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Sedimentology of the Mist Mountain formation, in the Fording River area, southeastern Canadian Rocky… Donald, Roberta L. 1984

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SEDIMENTOLOGY OF THE MIST MOUNTAIN FORMATION, IN THE FORDING RIVER AREA, SOUTHEASTERN CANADIAN ROCKY MOUNTAINS By ROBERTA L. DONALD B . S c , The U n i v e r s i t y of A l b e r t a , 1980 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n THE FACULTY OF GRADUATE STUDIES Department of G e o l o g i c a l S c i e n c e s We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o the r e q u i r e d s t a n d a r d THE UNIVERSITY OF A p r i l (c) R o b erta L. BRITISH 1984 Donald, COLUMBIA 1984 In presenting t h i s thesis i n p a r t i a l f u l f i l m e n t of the requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y available for reference and study. I further agree that permission for extensive copying of t h i s thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. I t i s understood that copying or publication of t h i s thesis for f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of Geological Sciences The University of B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 Date April 27. 1984 DE-6 n/Rn i i ABSTRACT The Upper J u r a s s i c - L o w e r C r e t a c e o u s M i s t Mountain F o r m a t i o n a t the F o r d i n g Mine i n s o u t h e a s t e r n B r i t i s h Columbia i s a 550 metre t h i c k i n t e r v a l o f non-marine, c o a l - b e a r i n g s e d i m e n t s . Three u n i t s can be d i s t i n g u i s h e d i n the s t r a t i g r a p h i c sequence based on sandstone body geometry and c o a l seam c h a r a c t e r i s t i c s . U n i t I , the lowermost u n i t , r e p r e s e n t s p r o g r a d i n g lower c o a s t a l p l a i n d e p o s i t s . Two major d i s t r i b u t a r y c h a n n e l s t r e n d e d n o r t h w e s t - s o u t h e a s t t h r o u g h the st u d y a r e a . These c h a n n e l s l i m i t e d the l a t e r a l e x t e n t of c o e x i s t i n g peat swamps r e s p o n s i b l e f o r c o a l seams 1, 2 and 3. The d o m i n a n t l y herbaceous peats grew i n hummock and d e p r e s s i o n topography i n i n t e r c h a n n e l a r e a s . C r e v a s s e s p l a y and overbank d e p o s i t s f l o o d e d peat swamps c a u s i n g c e s s a t i o n of growth and d e p o s i t i o n o f f i n e - g r a i n e d muds and s i l t s on peat s u r f a c e s . These mud and s i l t beds are the mudstone and s i l t s t o n e p a r t i n g s t h a t o c c u r i n the M i s t Mountain c o a l s . U n i t I I sediments accumulated i n a f l u v i a l - f l o o d p l a i n e nvironment. R i v e r s t r e n d e d n o r t h e a s t - s o u t h w e s t i n a wide meander b e l t . Peat swamps s u p p o r t e d herbaceous and ar b o r a c e o u s p l a n t s and were f r e q u e n t l y d i s t u r b e d by c o e x i s t i n g r i v e r s . R i v e r and s p l a y w a t e r s a c t i v e l y eroded p e a t s and d e p o s i t e d f i n e - t o medium-grained sediments on peat s u r f a c e s . The sediments o f U n i t I I I were d e p o s i t e d i n a f l o o d p l a i n dominated environment on the upper c o a s t a l p l a i n . Major r i v e r s were c o n c e n t r a t e d o u t s i d e of the s t u d y a r e a a l l o w i n g t h i c k f o r e s t peat a c c u m u l a t i o n s . Lake and f l o o d waters c o v e r e d peats c a u s i n g mudstone s p l i t s i n some c o a l seams and some a r g i l l a c e o u s c o a l s . C o a l s o f the M i s t Mountain F o r m a t i o n are low i n s u l f u r (<0.8%) r e f l e c t i n g f r e s h water t e r r e s t r i a l o r i g i n and l a c k of marine i n f l u e n c e . Ash c o n t e n t o f the c o a l s (5-33%) r e f l e c t s a c o m b i n a t i o n o f b i o l o g i c a l l y d e r i v e d , a u t h i g e n i c and d e t r i t a l a s h . A u t h i g e n i c ash i s i n the form of s p h e r u l i t i c s i d e r i t e p a r t i n g s , whereas mudstone and s i l t s t o n e p a r t i n g s c o n s t i t u t e the d e t r i t a l ash. M a c e r a l s i n the M i s t Mountain c o a l s r e f l e c t the c h a n g i n g d e p o s i t i o n a l environments i n which the peats formed. Lower c o a l s i n U n i t s I and I I a r e h i g h i n i n e r t i n i t e and low i n v i t r i n i t e . H i g h e r i n the s t r a t i g r a p h i c s e c t i o n the c o a l s are low i n i n e r t i n i t e and h i g h i n v i t r i n i t e w hich r e f l e c t s the peat c o m p o s i t i o n and the degree of peat d e g r a d a t i o n . The d e p o s i t i o n a l environments o f the M i s t Mountain Formation a t E a g l e Mountain have a marked i n f l u e n c e on the mine-a b i l i t y o f the c o a l . C o a l seam t h i c k n e s s and l a t e r a l c o n t i n u i t y a re m o d i f i e d by sandstone b o d i e s . D r a p i n g of c o a l seams over c h a n n e l sandstones and c h a n n e l washouts of c o a l have r e s u l t e d i n r a p i d v a r i a t i o n s i n i n t e r b u r d e n t h i c k n e s s . P r e d i c t i o n of sandstone geometry w i l l a l l o w more a c c u r a t e d e f i n i t i o n of c o a l r e s e r v e s and seam t r e n d s i n i n i t i a l e x p l o r a t i o n s t a g e s . P i t d e s i g n and b l a s t i n g can a l s o b e n e f i t from a d e t a i l e d knowledge of permeable sandstone b o d i e s . By a c c u r a t e l y d e f i n i n g sandstone t r e n d s , water seepage i n t o p i t s can be m i n i m i z e d i m p r o v i n g h i g h w a l l s t a b i l i t y and m a x i m i z i n g b l a s t r e s u l t s . i v ACKNOWLEDGEMENTS I w i s h t o thank my s u p e r v i s o r Dr. R. M. B u s t i n and commit-tee members W. H. Mathews and J . W. Murray f o r t h e i r g u i d a n c e , a d v i c e and c r i t i c a l r e v i e w s t h r o u g h o u t t h i s s t u d y . D i s c u s s i o n s w i t h J . D. Hughes and D. W. Gibson were v e r y h e l p f u l and are much a p p r e c i a t e d . S c o t t C a r m i c h a e l p r o v i d e d e x c e l l e n t a d v i c e and d i s c u s s i o n whenever i t was needed and I thank him f o r h i s time and p a t i e n c e . F i n a n c i a l a s s i s t a n c e and ac c e s s t o a l l c o a l mine d a t a were p r o v i d e d by F o r d i n g Coal L i m i t e d . The e n t i r e s t a f f a t F o r d i n g was v e r y h e l p f u l d u r i n g the s t u d y , but I e s p e c i a l l y want t o thank Ken Komenac, Don M i l l s , R i c h a r d Dean and P e t e r D a i g n a u l t f o r a l l t h e i r a s s i s t a n c e . A d d i t i o n a l Funding was p r o v i d e d by N.S.E.R.C. Grant 67-7337 t o Dr. R.M. B u s t i n . Dr. C. Godwin and I n t e r n a t i o n a l Geosystems C o r p o r a t i o n k i n d l y a l l o w e d me t o u t i l i z e t h e i r d a t a c o l l e c t i o n system. Dr. G. Rouse i s thanked f o r i d e n t i f i c a t i o n o f f o s s i l samples. Many thanks go t o the U.B.C. Geology s t a f f and t e c h n i c i a n s f o r sample p r e p a r a t i o n and a n a l y s e s . T h e s i s d r a f t i n g was done by Gordon Hodge. E. Montgomerey and G. Dunlop are thanked f o r t h e i r t e c h n i c a l a s s i s t a n c e and moral s u p p o r t . TABLE OF CONTENTS I . INTRODUCTION 1 1.1. OBJECTIVES AND STUDY LOCATION 1 1.2. PREVIOUS WORK 6 1.3. GEOLOGICAL HISTORY ...9 1.4. METHODS AND DATA 11 I I . LITHOSTRATIGRAPHY AND PALEOENVIRONMENTS 15 2.1. GENERAL STRATIGRAPHY AND STRUCTURE 15 2.2. EXPLANATION OF TERMS 20 2.3. LITHOFACIES 23 2.3.1. Channel D e p o s i t s 23 2.3.2. Crevasse S p l a y D e p o s i t s 25 2.3.3. N a t u r a l Levee D e p o s i t s 30 2.3.4. F l o o d B a s i n D e p o s i t s 31 2.4. LITHOFACIES DESCRIPTIONS AND SEDIMENTOLOGY 35 2.4.1. U n i t I C h a r a c t e r i s t i c s 35 2.4.2. U n i t I Sedimentology 45 2.4.3. U n i t I I C h a r a c t e r i s t i c s 57 2.4.4. U n i t I I Sedimentology 76 2.4.5. U n i t I I I C h a r a c t e r i s t i c s 83 2.4.6. U n i t I I I Sedimentology 100 2.5. DEPOSITIONAL HISTORY OF THE MIST MOUNTAIN FORMATION.112 I I I . SEDIMENTOLOGICAL ASPECTS OF COAL OCCURRENCE ON EAGLE MOUNTAIN 120 3.1. INTRODUCTION 120 3.2. DEPOSITIONAL FACTORS CONTROLLING SEAM PARAMETERS ...121 3.3. COAL SEAM CHARACTERISTICS 125 v i 3.3.1. P r o x i m a t e A n a l y s i s Data 125 3.3.2. P e t r o g r a p h i c Data 131 3.3.3. Rank 138 3.4. APPLICATIONS OF DEPOSITIONAL HISTORY TO MINING OPERATION 138 SUMMARY AND CONCLUSIONS 142 APPENDIX I - P a l e o n t o l o g y Summary 147 APPENDIX I I - T h i n S e c t i o n A n a l y s e s 149 APPENDIX I I I - C l a y M i n e r a l o g y 151 APPENDIX IV - C o a l P a r t i n g A n a l y s e s 155 APPENDIX V - Wentworth S i z e S c a l e 161 APPENDIX VI - R e p r e s e n t a t i v e L i t h o l o g i c Samples 162 APPENDIX V I I - G e o l o g i c a l Symbols Used 171 REFERENCES 172 v i i LIST OF TABLES I . R e p r e s e n t a t i v e P r o x i m a t e A n a l y s e s . 126 I I . C o a l P e t r o g r a p h y Data 133 v i i i LIST OF FIGURES 1. L o c a t i o n Map of F o r d i n g R i v e r O p e r a t i o n s 3 2. Area L o c a t i o n Map 4 3. E a g l e Mountain Study Area B o u n d a r i e s 5 4. Nomenclature o f the Kootenay Group and i t s R e l a t i o n -s h i p t o P r e v i o u s Terminology 8 5. E a g l e Mountain P a l i n s p a s t i c Map 12 6. Example of I n i t i a l C o r r e l a t i o n P r o c e s s U s i n g Geophys-i c a l Log Responses 181 7. G e n e r a l i z e d G e o l o g i c a l Cross S e c t i o n on E a g l e Moun-t a i n 19 8. G e n e r a l i z e d S t r a t i g r a p h i c S e c t i o n of the Kootenay Group 21 9. C r o s s S e c t i o n 1 182 <vi 10 C r o s s S e c t i o n 2 183 " 11 Cross S e c t i o n 3 184 " 12. Cross S e c t i o n 4 185 « 13. C r o s s S e c t i o n 5 186 u 14. R e p r e s e n t a t i v e Gamma Ray Responses For Cha n n e l , P r o x -i m a l S p l a y and D i s t a l S p l a y 28 15. D.D.H. 1758 Sediments of U n i t I 37 16. D.D.H. 1628 Sediments of U n i t I 38 17. Clode Creek T r a v e r s e 1-2 Sediments o f U n i t I 41 18. "A" Channel I s o l i t h Map and C o a l Seam 2 Isopach Map ..43 19. D.D.H. 1628 Sediments of U n i t I I 46 20. a,b,c S u c c e s s i v e D e p o s i t i o n a l Environments of U n i t I i x Sediments 51 20. d,e,f S u c c e s s i v e D e p o s i t i o n a l Environments o f U n i t I Sediments 53 20. g S u c c e s s i v e D e p o s i t i o n a l Environments o f U n i t I Sediments 56 21. "B" Channel I s o l i t h Map and Co a l Seam 5 Lower Isopach Map ' 60 22. Clode P i t West T r a v e r s e Sediments of U n i t I I 61 23. E a g l e Southwest T r a v e r s e 1-3 Sediments of U n i t I I ....62 24. D.D.H. 1752 Sediments of U n i t I I 65 25. "C" Channel I s o l i t h Map and C o a l Seam 5 Upper Isopach Map 6 7 26. N a t u r a l S c a l e Diagram of a P o r t i o n of 5 t o 9 Seam I n t e r v a l From Cross S e c t i o n 1 68 27. "D" Channel I s o l i t h Map and C o a l Seam 9 Isopach Map ..71 28. D.D.H. 1750 Sediments o f U n i t I I , S t a c k e d "D" Sand-stone 73 29. N a t u r a l S c a l e Diagram of a P o r t i o n o f the 7 t o 9 Seam I n t e r v a l From Cro s s S e c t i o n 5 75 30. a,b,c S u c c e s s i v e D e p o s i t i o n a l Environments o f U n i t I I Sediments 77 30. d,e,f S u c c e s s i v e D e p o s i t i o n a l Environments o f U n i t I I Sediments 79 30. g , h , i S u c c e s s i v e D e p o s i t i o n a l Environments of U n i t I I Sediments 81 31. E a g l e SW T r a v e r s e 4-6, Sediments of U n i t I I and U n i t I I I 86 X 32. D.D.H. 1758 Sediments of U n i t I I I 88 33. T a y l o r P i t T r a v e r s e , Sediments o f U n i t I I I 89 34. D.D.H. 1757 , Sediments of U n i t I I I 95 35. D.D.H. 1752 , Sediments of U n i t I I I 97 36. a,b,c S u c c e s s i v e D e p o s i t i o n a l Environments of U n i t I I I Sediments 101 36. d,e,f S u c c e s s i v e D e p o s i t i o n a l Environments o f U n i t I I I Sediments 103 36. g , h , i S u c c e s s i v e D e p o s i t i o n a l Environments of U n i t I I I Sediments 105 36. j , k , l S u c c e s s i v e D e p o s i t i o n a l Environments of U n i t I I I Sediments 109 36. m,n,o S u c c e s s i v e D e p o s i t i o n a l Environments of U n i t I I I Sediments I l l 36. p,q S u c c e s s i v e D e p o s i t i o n a l Environments of U n i t I I I Sediments 113 37. "E" Channel I s o l i t h Map and Co a l Seam 12 Isopach Map .107 38. Environment of D e p o s i t i o n o f the Kootenay Group Sediments 115 39. C l a y M i n e r a l P e r c e n t a g e s i n Mudstone P a r t i n g s 153 x i LIST OF PLATES 1. P r o x i m a l C r e v a s s e Channel Sandstone T r u n c a t i n g F l o o d B a s i n S i l t s t o n e and Mudstone 99 2 . Sample D016 .163 3 . Sample D018 .164 4. Sample D022 165 5. Sample D027 166 6. Sample D031 167 7 . Sample D056 168 8. Sample D057 169 9. Sample D060 170 1 I . INTRODUCTION 1.1. OBJECTIVES AND STUDY LOCATION The s u r f a c e m i n e a b i l i t y o f s o u t h e a s t e r n Canadian C o r d i l l e r a n c o a l seams depends.on many f a c t o r s . These i n c l u d e a c c e s s i b i l i t y , c o a l q u a l i t y and q u a n t i t y , topography and s t r u c t u r a l d e f o r m a t i o n . When thes e f a c t o r s come t o g e t h e r i n a f a v o r a b l e c o m b i n a t i o n , and a market f o r the p r o d u c t i s e s t a b l i s h e d , mines are opened and the s u r f a c e and underground removal of c o a l i s c a r r i e d o u t . C o a l seam geometry, t h i c k n e s s and o v e r a l l q u a l i t y are d i r e c t l y r e l a t e d t o the environment of peat swamp d e p o s i t i o n and p o s t - d e p o s i t i o n a l m o d i f i c a t i o n by d i a g e n e s i s , e r o s i o n and s t r u c t u r a l d e f o r m a t i o n . P r e d i c t i o n of c o a l seam parameters i s a v a l u a b l e t o o l t h a t can be used not o n l y i n the e x p l o r a t i o n s t a g e but a l s o i n the a c t i v e m i n i n g phase. In most areas poor o u t c r o p exposure and l a c k o f s u b s u r f a c e d a t a a r e not c o n d u c i v e t o d e t a i l e d s e d i m e n t o l o g i c a l a n a l y s e s of the c o a l measures. One n o t a b l e e x c e p t i o n i s the F o r d i n g R i v e r E a g l e Mountain mine s i t e . Here, r o a d c u t s , p i t f a c e s and n a t u r a l exposures can be combined w i t h e x t e n s i v e d r i l l h o l e d a t a t o f a c i l i t a t e a d e t a i l e d a n a l y s i s o f the s e d i m e n t o l o g y of the M i s t Mountain F o r m a t i o n . The purpose o f t h i s s t u d y i s t o d e t e r m i n e , s e d i m e n t o l o g i c -a l l y , a d e p o s i t i o n a l model f o r the L a t e J u r a s s i c - E a r l y C r e t a c e o u s M i s t Mountain F o r m a t i o n a t E a g l e Mountain. The major o b j e c t i v e s of t h i s s t u d y are t o : 2 1. D e f i n e major c l a s t i c l i t h o f a c i e s i n the M i s t Mountain F o r m a t i o n ; 2. Determine l i t h o f a c i e s a s s o c i a t i o n s u s i n g d e t a i l e d s e d i m e n t o l o g y ; 3. Develop d e p o s i t i o n a l models f o r the major c l a s t i c u n i t s and; 4. R e l a t e c o a l seam parameters ( l a t e r a l c o n t i n u i t y , c o a l q u a l i t y and t h i c k n e s s ) t o d e p o s i t i o n a l s e t t i n g . The F o r d i n g c o a l mine i s l o c a t e d i n the F r o n t Ranges of the Rocky Mo u n t a i n s , t h i r t y k i l o m e t r e s n o r t h o f the town of E l k f o r d , B.C. ( F i g u r e 1 ) . Access t o E l k f o r d i s v i a the Crowsnest highway #3 t o Sparwood, then n o r t h by paved highway t h i r t y - s i x k i l o m e t r e s ( F i g u r e 2 ) . The mine s i t e i s s i t u a t e d i n the upper E l k R i v e r v a l l e y c o a l b a s i n and s t r a d d l e s the F o r d i n g R i v e r . M i n i n g i s c a r r i e d out on the m o d e r a t e l y s l o p i n g v a l l e y w a l l s up t o an e l e v a t i o n o f 2438 metres. C o a l p r e p a r a t i o n o c c u r s a t an e l e v a t i o n o f 1650 metres on the r e l a t i v e l y f l a t f l o o r of the upper F o r d i n g R i v e r v a l l e y . The l o c a l topography r e f l e c t s the s t r u c t u r a l c o n t r o l of the u n d e r l y i n g f o l d e d and f a u l t e d s e d i m e n t a r y r o c k s c r e a t i n g c o n d i t i o n s amenable t o open p i t m i n i n g methods. M i n i n g i s c o n c e n t r a t e d i n the c o a l - b e a r i n g M i s t Mountain F o r m a t i o n of the Kootenay Group (Gib s o n , 1979). The s t u d y c e n t r e s on E a g l e Mountain i n the e a s t e r n p a r t o f the m i n i n g a r e a ( F i g u r e 3 ) . The e a s t e r n and w e s t e r n b o u n d a r i e s are d e l i m i t e d by s u r f a c e t r a c e s of the c o n t a c t between the M o r r i s e y F o r m a t i o n and the u n d e r l y i n g F e r n i e F o r m a t i o n . The n o r t h e r n and s o u t h e r n b o u n d a r i e s are Clode and K i l m a r n o c k 3 A L B E R T A I \ Figure 1 Loca t ion map of Ford ing River Operat ions (after Tapl in, 1976) 4 Figure 2 A r e a locat ion map (after L a n e , 1980) . 5 Figure 3. Eagle Mountain study area boundaries (modified from Gibson and Hughes, 1981). 6 c r e e k s . The study a r e a c o v e r s a p p r o x i m a t e l y t w e l v e square k i l o m e t r e s . The e n t i r e M i s t Mountain F o r m a t i o n was not examined, but r a t h e r the s t u d y f o c u s s e d on the i n t e r v a l from the b a s a l c o n t a c t w i t h the M o r r i s e y F o r m a t i o n t o the upper c o n t a c t of C o a l Seam 15. The approximate t h i c k n e s s o f t h i s sequence i s 500 metres. 1.2. PREVIOUS WORK The Kootenay Group of s o u t h e a s t e r n B r i t i s h Columbia has been under i n v e s t i g a t i o n s i n c e 1886. At t h i s time S i r J . W. Dawson proposed the name K o o t a n i e S e r i e s f o r the lower p a r t of the Mesozoic r o c k s u c c e s s i o n i n s o u t h e r n A l b e r t a . Leach (1912) named the F e r n i e s h a l e s c r e a t i n g a lower c o n t a c t f o r the K o o t a n i e , which he renamed the Kootenay F o r m a t i o n . In 1902 McEvoy d e s c r i b e d a d i s t i n c t i v e , c l i f f - f o r m i n g sandstone e q u i v a l e n t t o the Kootenay F o r m a t i o n i n the F e r n i e a r e a . Other e a r l y s t r a t i g r a p h e r s i n c l u d e C a i r n e s (1914) and Rose (1917), who d e s c r i b e d the base of the Kootenay F o r m a t i o n a t Moose Mountain, A l b e r t a and the Crows Nest P a s s , r e s p e c t i v e l y . The M i s t Mountain s t r a t a were p r e v i o u s l y grouped as p a r t of the Kootenay F o r m a t i o n (Newmarch, 1953; N o r r i s , 1959; P r i c e , 1962, 1965) and were d i v i d e d i n t o t h r e e members by N o r r i s (1959), based on exposures a t the type s e c t i o n of G r a s s y Mountain. These were, i n a s c e n d i n g o r d e r , the Adanac, H i l l c r e s t and Mutz Members. Because the d i v i s i o n s c o u l d not be r e c o g n i z e d r e g i o n a l l y G i b s o n (1979) r e d e f i n e d the s u c c e s s i o n w i t h the type 7 s e c t i o n l o c a t e d on the w e s t e r n spur o f M i s t Mountain, A l b e r t a , which i s 50 k i l o m e t r e s n o r t h of the s t u d y a r e a . The l o c a t i o n and type s e c t i o n are d e s c r i b e d i n Gibson (1979). Gibson's nomenclature f o r the 1 i t h o s t r a t i g r a p h i c s u c c e s s i o n between the Lower C r e t a c e o u s B l a i r m o r e Group and the J u r a s s i c F e r n i e F o r m a t i o n i s i l l u s t r a t e d i n f i g u r e 4. R e g i o n a l s t r u c t u r a l s t u d i e s c a r r i e d out on the Kootenay Group i n c l u d e t h o s e by P r i c e (1962, 1965), N o r r i s (1964, 1971), Da h l s t r o m (1970) and B u s t i n (1979). F r e b o l d (1957) p r o v i d e s a good summary of p r e v i o u s work c o n c e r n i n g paleogeography i n the J u r a s s i c . S t e l c k e t a l . (1972) and Hamblin and Walker (1979) a l s o d i s c u s s J u r a s s i c - C r e t a c e o u s paleogeography i n the s o u t h e r n Rocky Mountains. P a l e o b o t a n i c a l and p a l y n o l o g i c a l s t u d i e s conducted by Rouse (1959), Pocock (1964) and B e l l (1956) were the means of d a t i n g the Kootenay Group. R e g i o n a l p e t r o g r a p h y of the Kootenay r o c k s and c o a l seams has been p r o v i d e d by Cameron (1972) and Rapson (1965). On a l o c a l s c a l e s t r a t i g r a p h i c - s t r u c t u r a l mapping has been c a r r i e d out by Graham e t a l . (1977) i n the upper E l k R i v e r V a l l e y and by Pearson and G r i e v e (1980) a t the F o r d i n g mine s i t e . T a p l i n (1976) has d e s c r i b e d mine ge o l o g y and g e o l o g i c a l p r a c t i c e s a t the F o r d i n g mine s i t e . The c o n t a c t o f the Kootenay Group w i t h the u n d e r l y i n g J u r a s s i c F e r n i e F o r m a t i o n i s g r a d a t i o n a l and thus the c o n t a c t has been s e l e c t e d a t d i f f e r e n t l e v e l s by such a u t h o r s as Beach (1943) , A l l e n and C a r r (1947) , Newmarch (1953) , F r e b o l d (1957) , 8 A L B E R T A (N orris, 1959) BRITISH C O L U M B I A (Newmarch, 1953) A L B E R T A BRIT ISH C O L U M B I A (Gibson, 1981) ui O < A L B E R T A BRIT ISH C O L U M B I A (Jansa, 1972) C E N T R A L F O O T H I L L S , A L B E R T A (Stott, 7975; CADOMIN FM. CADOMIN FM. C A D O M I N F M . < cc O > < Z UJ H o o Mutz Member Hil lcrest Member Adanac Member M o o s e Mountain Mbr. P o c a t e r r a C k . Mbr . < 2 CC O LL LU < CC o u. >-< z UJ \— o o Q. Z> O CC o >-< z UJ H O o B a s a l Kootenay S a n d FERNIE F M . F E R N I E F M . z o i -< tr o LL UJ z o I-< CC o LL z < z O 2 »-CO CO D O LU o < H LU CC o CC < LU CADOMIN FM C A D O M I N F M . < 2 cc o LL < z LU I-o o > LU CO cc2 CCLL O 2 Moose Mountain Mbr. Weary Ridge Mbr. FERNIE F M . O W £ co co CC c LU O HQ. < w < 2 CC O LL -I LU E CO c CO 0) m "co o O < 2 CC o CO CO < z < M o o s e Mountain Mbr. F E R N I E F M , F E R N I E F M . Figure 4. Nomenclature of the K o o t e n a y Group and its re lat ionship to prev ious terminology (modified from Gibson and Hughes , 1981) 9 P r i c e (1962, 1965) and Jansa (1972). 1.3. GEOLOGICAL HISTORY The s o u t h e r n Rocky Mountains were the s i t e o f m i o g e o c l i n a l s e d i m e n t a t i o n from L a t e P r o t e r o z o i c u n t i l E a r l y J u r a s s i c (Gibson and Hughes, 1981). An E a r l y J u r a s s i c u p l i f t ' b e v e l l e d Devonian t o T r i a s s i c s t r a t a from e a s t t o west. T h i s event was f o l l o w e d by t r a n s g r e s s i o n of the J u r a s s i c F e r n i e Sea ( S t e l c k e t a l . , 1972). S e d i m e n t a t i o n , b e g i n n i n g i n E a r l y S i n e m u r i a n , r e s u l t e d i n the d e p o s i t i o n o f marine F e r n i e s h a l e s . F r e b o l d (1957) has o u t l i n e d the v a r i o u s p e r i o d s of t r a n s g r e s s i o n s and r e g r e s s i o n s t h a t o c c u r r e d based on d i a s t e m s . The f i n a l r e g r e s s i o n o f the F e r n i e Sea, a c c o r d i n g t o F r e b o l d (1957), o c c u r r e d a t the end o f the P o r t l a n d i a n . The r e g r e s s i o n was a r e s u l t of e p e i r o g e n i c u p l i f t c e n t e r e d i n the B l a c k H i l l s o f South Dakota t o the s o u t h and the P u r c e l l Mountains and the Shushwap Complex t o the west ( J a n s a , 1972). U p l i f t i n t h e s e a r e a s was caused by one of two major t e c t o n i c e v e n t s a f f e c t i n g the m i o g e o c l i n a l sediments of the s o u t h e r n Rocky Mountains. These t e c t o n i c e v e n t s were the Columbian and Laramide O r o g e n i e s . The f i r s t t e c t o n i c event was presumably a r e s u l t of a c o l l i s i o n o f an a l l o c h t h o n o u s t e r r a n e w i t h the s t a b l e N o r t h American c r a t o n t h a t caused u p l i f t and a s s o c i a t e d t h r u s t i n g and f o l d i n g i n the c r a t o n i c r o c k s (Gibson and Hughes, 1981) . T h i s L a t e J u r a s s i c - E a r l y C r e t a c e o u s t e c t o n i c event was a s s o c i a t e d 10 w i t h the Columbian Orogeny. D u r i n g the Columbian Orogeny, i n f i l l i n g of the s o u t h e r n margin o f the F e r n i e sea o c c u r r e d as e l a s t i c s were shed from u p l i f t e d c r y s t a l l i n e b e l t s . S e d i m e n t - b e a r i n g r i v e r s f l o w e d n o r t h and n o r t h e a s t towards the Western A l b e r t a B a s i n . Advancing s h o r e l i n e s and c o a s t a l p l a i n s l a i d down the K o o t e n a y - B l a i r m o r e c l a s t i c wedge ( S t e l c k e t a l . , 1972). F a r t h e r n o r t h t h e s e d e l t a complexes grade i n t o marine o f f s h o r e sand d e p o s i t s o f the N i k a n a s s i n F o r m a t i o n which p r o v i d e s e v i d e n c e of t h i s p r o g r a d a t i o n . J ansa (1972) has de t e r m i n e d t h a t i n the e a r l y s t a g e s o f d e l t a p r o g r a d a t i o n the de p o c e n t r e was l o c a t e d a t Vo l c a n o Creek, 60 k i l o m e t e r s n o r t h o f E a g l e Mountain. The l a t e r a l e x t e n t of the N i k a n a s s i n c l a s t i c wedge was 66 k i l o m e t r e s . L a t e r a l d i a c h r o n i s m o f the Moose Mountain Member of the M o r r i s e y F o r m a t i o n over the F e r n i e s h a l e s t o the n o r t h and s o u t h of t h i s d e p o c e n t r e i s good e v i d e n c e o f p r o g r a d a t i o n ( J a n s a , 1972). The second t e c t o n i c e v e n t , the Laramide Orogeny, a f f e c t e d the s o u t h e r n Rocky Mountain m i o g e o c l i n a l a r e a w i t h a s i m i l a r c o l l i s i o n o f an a l l o c h t h o n o u s t e r r a n e w i t h the c r a t o n d u r i n g L a t e C r e t a c e o u s t o E a r l y T e r t i a r y t imes (Gibson and Hughes, 1981). The Laramide Orogeny ac c o u n t s f o r the complex s t r u c t u r a l s t y l e found i n the Main and F r o n t Ranges and F o o t h i l l s of the Rocky Mountains. The r e s u l t i n g i m b r i c a t e t h r u s t f a u l t s and f o l d s were l a t e r deformed by a l a t e s tage of normal f a u l t i n g i n the Q u a t e r n a r y . 11 1.4. METHODS AND DATA G e o p h y s i c a l l o g s from 200 diamond and r o t a r y d r i l l h o l e s were a v a i l a b l e from E a g l e Mountain. Gamma r a y and n e u t r o n l o g t r a c e s were examined i n d e t a i l t o determine l i t h o l o g i e s . To c o r r e c t l y d etermine the c o n f i g u r a t i o n o f s t r a t a a t the time o f d e p o s i t i o n , a p a l i n s p a s t i c map was c o n s t r u c t e d from the Ea g l e Mountain d r i l l h o l e l o c a t i o n map ( F i g u r e 5 ) . An a r b i t r a r y b a s e l i n e was chosen on the e a s t s i d e of the st u d y a r e a p a r a l l e l t o s t r u c t u r a l s t r i k e . On Ea g l e Mountain, s t r i k e i s n o r t h w e s t -s o u t h e a s t . One major s y n c l i n e and two major t h r u s t f a u l t s r o u g h l y p a r a l l e l t h i s t r e n d . The average d i s p l a c e m e n t on the t h r u s t f a u l t s was f i r s t removed by moving the f a u l t s u r f a c e t r a c e s t o the southwest, p e r p e n d i c u l a r t o the b a s e l i n e . The amount t h a t each one was moved was c a l c u l a t e d from s t r u c t u r a l c r o s s s e c t i o n s p r o v i d e d by F o r d i n g C o a l L t d . T h i s procedure a l l o w e d removal o f the bed r e p e t i t i o n r e s u l t i n g from f a u l t i n g . The r e a s o n t h a t some d r i l l h o l e s a r e l a b e l l e d "top of d r i l l h o l e " and "bottom o f d r i l l h o l e " on the c r o s s s e c t i o n s i s because t h e y o c c u r on s e p a r a t e t h r u s t p l a t e s . The s h o r t e n i n g caused by the s y n c l i n e was removed by moving each d r i l l n o l e t o the southwest, p e r p e n d i c u l a r t o the b a s e l i n e , the amount o f which was c a l c u l a t e d from s t r u c t u r a l c r o s s s e c t i o n s . The d r i l l h o l e s and s t r a t a t h e r e b y r e s t o r e d t o t h e i r o r i g i n a l d e p o s i t i o n a l p o s i t i o n s produce a p a l i n s p a s t i c map. The p a l i n s p a s t i c map was used as a b a s i s f o r a l l i s o l i t h s , i s o - a s h maps and c r o s s s e c t i o n s . 13 Isopach and raw c o a l ash c o n t e n t maps were c o n s t r u c t e d f o r c o a l seams 2, 5L, 5U, 9 and 12. The c o r r e c t e d t h i c k n e s s of the c o a l was c a l c u l a t e d from g e o p h y s i c a l l o g s . I s o - a s h map d a t a was c o l l e c t e d from w a s h a b i l i t y s t u d i e s done on s e l e c t e d seams by F o r d i n g C o a l ' s l a b o r a t o r y . Only th o s e seams w i t h t h e most a v a i l a b l e d a t a were c o n t o u r e d . These maps can be found i n the t e x t ( F i g u r e s 18, 21, 25, 27, 3 7 ) . Cross s e c t i o n l i n e s were e s t a b l i s h e d i n areas o f . h i g h e s t d r i l l h o l e d e n s i t y ( F i g u r e s 6, 9-13, Map P o c k e t ) . S e l e c t e d l o g s were used t o c o r r e l a t e c o a l seams and l i t h o l o g i e s . F i g u r e 6 (Map Pocket) i s an example of t h i s i n i t i a l c o r r e l a t i o n p r o c e s s . E l e v e n o u t c r o p s e c t i o n s and s i x d r i l l h o l e c o r e s (3611 metres) were examined w i t h l i t h o l o g y and s e d i m e n t o l o g y emphasized t o ensure c o r r e c t i n t e r p r e t a t i o n o f the c o r r e s p o n d i n g g e o p h y s i c a l t r a c e s . E i g h t c r o s s s e c t i o n s were c o n s t r u c t e d from g e o p h y s i c a l l o g s . S i x were o r i e n t e d p e r p e n d i c u l a r t o the b a s e l i n e and the l o c a l s t r u c t u r a l t r e n d . Two o f th e s e were l a t e r o m i t t e d because poor c o n t r o l and i n f e r i o r l o g q u a l i t y made c o r r e l a t i o n d i f f i c u l t . Two c r o s s s e c t i o n s were o r i e n t e d p a r a l l e l t o the b a s e l i n e . Number 9 c o a l seam was used as a datum f o r a l l s e c t i o n s . I t o c c u r s a p p r o x i m a t e l y m i d - s e c t i o n and i s e a s i l y i d e n t i f i e d by i t s d i s t i n c t i v e g e o p h y s i c a l c h a r a c t e r i s t i c s . A m i d - s e c t i o n datum was chosen t o mi n i m i z e d i s t o r t i o n o f sediments due t o d i f f e r e n t i a l c ompaction. R e p r e s e n t a t i v e samples were t a k e n from v a r i o u s l i t h o l o g i e s t h r o u g h o u t the s t r a t i g r a p h i c sequence from o u t c r o p s and 14 d r i l l h o l e c o r e s . In t o t a l , 62 samples were t a k e n . Of the s e samples, 7 were f o r f o s s i l i d e n t i f i c a t i o n , 8 were t h i n s e c t i o n e d f o r a n a l y s e s of m i n e r a l c o m p o s i t i o n , 11 were a n a l y z e d by X-ray d i f f r a c t i o n f o r d e t e r m i n a t i o n of c l a y m i n e r a l s , 11 were t a k e n f o r c o a l p a r t i n g a n a l y s i s and 14 were t a k e n as examples o f s e d i m e n t a r y f e a t u r e s . S e v e r a l samples were a n a l y z e d u s i n g more tha n one o f the above t e c h n i q u e s . E l e v e n samples p r e v i o u s l y c o l l e c t e d by F o r d i n g were a n a l y z e d f o r c o a l p a r t i n g c o m p o s i t i o n . The f o s s i l samples were i d e n t i f i e d by Dr. G. Rouse a t the U n i v e r s i t y o f B r i t i s h Columbia. R e s u l t s are g i v e n i n Appendix I . E i g h t t h i n s e c t i o n s were a n a l y z e d s e m i - q u a n t i t a t i v e l y t o determine framework and m a t r i x m i n e r a l s and cement t y p e s . T h i s was done u s i n g a p e t r o g r a p h i c m i c r o s c o p e . R e s u l t s a r e p r e s e n t e d i n Appendix I I . The p r o c e d u r e s used i n a n a l y z i n g the e l e v e n c l a y s t o n e and s h a l e samples f o r m i n e r a l o g y are d e s c r i b e d i n Appendix I I I . The p r o c e d u r e s used i n a n a l y z i n g 11 samples f o r c o a l p a r t i n g m i n e r a l o g y are d e s c r i b e d i n Appendix IV. The 11 a d d i t i o n a l t h i n s e c t i o n s p r o v i d e d by F o r d i n g were a n a l y z e d s e m i - q u a n t i t a t i v e l y f o r m i n e r a l o g y u s i n g a p e t r o g r a p h i c m i c r o s c o p e . In a d d i t i o n , 4 of t h e s e samples were examined u s i n g a Scanning E l e c t r o n M i c r o s c o p e . E i g h t c o r e samples were photographed and are p r e s e n t e d i n the t e x t as examples o f s e d i m e n t a r y f e a t u r e s found i n r o c k s t h a t r e p r e s e n t d i f f e r e n t d e p o s i t i o n a l e n v i r o n m e n t s . The M u n s e l l i d e n t i f i c a t i o n system was used t o d e s i g n a t e r o c k c o l o r s . 15 I I . LITHOSTRATIGRAPHY AND PALEOENVIRONMENTS 2.1. GENERAL STRATIGRAPHY The Kootenay Group has been mapped t h r o u g h o u t the Rocky Mountain F o o t h i l l s and the F r o n t Ranges from the U.S. b o r d e r n o r t h t o the N o r t h Saskatchewan R i v e r . N o r t h of the N o r t h Saskatchewan R i v e r the M o r r i s e y , M i s t Mountain and the E l k Formations grade l a t e r a l l y i n t o the marine-nonmarine N i k a n a s i n F o r m a t i o n . To the e a s t a t h i n n i n g of the c l a s t i c sediments o c c u r s because o f i n c r e a s i n g d i s t a n c e from the s o u r c e and because of removal by p r e - B l a i r m o r e e r o s i o n . The M i s t Mountain F o r m a t i o n i s the s t r a t i g r a p h i c i n t e r v a l o v e r l y i n g the M o r r i s e y F o r m a t i o n , and u n d e r l y i n g the E l k F o r m a t i o n of the Kootenay Group. The upper c o n t a c t o f the M i s t Mountain F o r m a t i o n w i t h the E l k F o r m a t i o n i s conformable and i s p l a c e d a t the base of the f i r s t sandstone or conglomerate t h a t o v e r l i e s the uppermost major c o a l seam of the M i s t Mountain F o r m a t i o n (Gibson and Hughes, 1981). The lower c o n t a c t w i t h the Moose Mountain Member of the M o r r i s e y F o r m a t i o n i s conformable and a b r u p t . The m a s s i v e , w e l l - i n d u r a t e d sandstones o f the Moose Mountain c o n t r a s t markedly w i t h the o v e r l y i n g r e c e s s i v e , carbonaceous s h a l e s , c o a l s and s i l t s t o n e s of the lower M i s t Mountain F o r m a t i o n . The s t r a t i g r a p h i c sequence a t E a g l e Mountain i s a non-marine s u c c e s s i o n composed of i n t e r b e d d e d s i l t s t o n e , s a n d s t o n e , mudstone, s i l t y s h a l e and c o a l . The t h i c k n e s s v a r i e s 16 from 500 t o 580 metres a c r o s s the s t u d y a r e a . S i l t s t o n e i s the predominant l i t h o l o g y i n the M i s t Mountain F o r m a t i o n . I t makes up 40-50% of t h e sequence (percentages were c a l c u l a t e d u s i n g c o r r e c t e d t h i c k n e s s e s on c r o s s s e c t i o n s ) . S i l t -s t one i s commonly t h i n - t o medium-bedded, weathers medium- t o d a r k - g r e y (N5-N3) 1, and i s i n t e r b e d d e d w i t h f i n e - g r a i n e d s a n d s t o n e . Where s i l t s t o n e i s i n t e r b e d d e d and i n t e r l a m i n a t e d w i t h mudstone, s h a l e and c o a l i t appears c o n s i d e r a b l y d a r k e r (N1-N2), and c o n t a i n s o r g a n i c m a t e r i a l . The predominant m i n e r a l i n s i l t s t o n e s i s q u a r t z w i t h l e s s e r amounts of c h e r t , c a r b o n a t e , and opaque m i n e r a l s (as d e t e r m i n e d by p e t r o g r a p h i c e x a m i n a t i o n ) . Where the s i l t s t o n e s a r e h i g h l y s i l i c e o u s and f e r r u g i n o u s they appear orange-brown (10 YR 6/6), i n weathered o u t c r o p . These beds are c h a r a c t e r i s t i c a l l y v e r y c a l c a r e o u s and w e l l i n d u r a t e d . The second most common l i t h o l o g y i s sandstone which makes up about 15% of the F o r m a t i o n . I t commonly weathers l i g h t - t o medium-grey (N7-N5), and i s c o a r s e - t o v e r y f i n e - g r a i n e d . I t o c c u r s as e i t h e r c hannel d e p o s i t s t h a t f i n e - u p w a r d s or as i n t e r b e d d e d s a n d s t o n e , s i l t s t o n e and s h a l e sequences t h a t e i t h e r c o a r s e n - or f i n e - u p w a r d s . Predominant m i n e r a l s are q u a r t z and c h e r t . S i l i c i f i e d r o c k f r a g m e n t s , and c a r b o n a t e and i r o n m i n e r a l s o c c u r i n s m a l l e r amounts. U s i n g F o l k ' s (1968) sandstone c l a s s i f i c a t i o n scheme, the sandstones of the M i s t Mountain F o r m a t i o n a r e 1 i t h a r e n i t e s . Mudstone and s h a l e comprise a p p r o x i m a t e l y 20-25% of the M u n s e l l C o l o r C h a r t N o t a t i o n 17 F o r m a t i o n and are g e n e r a l l y r e c e s s i v e i n o u t c r o p . They are a r g i l l a c e o u s and carbonaceous, w e a t h e r i n g d a r k - g r e y t o b l a c k (N3-N1), w i t h an orange-brown c o l o r (10 YR 6/6), where l i m o n i t i c o r p y r i t i f e r o u s l a m i n a t i o n s are p r e s e n t . C l a y m i n e r a l s i n t he mudstones are p r e d o m i n a n t l y i l l i t e and k a o l i n i t e , as det e r m i n e d by X-ray d i f f r a c t i o n a n a l y s e s (Appendix I I I ) . C o a l c o m p r i s e s 15-20% of the s t r a t i g r a p h i c sequence. Of the 15 seams s t u d i e d , named 1 th r o u g h 15 , t e n are c o n s i d e r e d m i n e a b l e . They range i n rank from low- t o h i g h - v o l a t i l e b i t u m i n o u s . S u l f u r i n the s e seams i s low (<0.8%), and raw ash c o n t e n t s range from 5-33%. The seams range from l e s s than 0.3 metres t o 31 metres i n t h i c k n e s s , i n c l u d i n g p a r t i n g s ( F i g u r e 8 ) . P r i m a r y s e d i m e n t a r y s t u c t u r e s a re common i n the s i l t s t o n e s and sandstones o f the stu d y a r e a . S m a l l - t o l a r g e - s c a l e c r o s s -bedding o c c u r s i n the sandstone c h a n n e l s i n the form o f p l a n a r -and t r o u g h - c r o s s b e d s . S m a l l e r s t r u c t u r e s i n c l u d e c u r r e n t - and w a v e - r i p p l e s , c l i m b i n g r i p p l e d r i f t s and, l e s s commonly, f l a s e r b e d d i n g . C o a l spar and l o a d c a s t s o c c u r i n ch a n n e l l a g d e p o s i t s . D e f o r m a t i o n f e a t u r e s i n s i l t s t o n e s and sandstones i n c l u d e s o f t - s e d i m e n t d e f o r m a t i o n s t r u c t u r e s , sand v o l c a n o e s and s i m i l a r d e w a t e r i n g s t r u c t u r e s , m i c r o - f a u l t i n g and sl u m p i n g . C o n v o l u t e t o wavy l a m i n a t i o n s and v e r t i c a l t o h o r i z o n t a l burrows a re common, w i t h r o o t l e t s b e i n g f a r l e s s f r e q u e n t . P e t r i f i e d t r e e t r u n k s a re common i n s i l t s t o n e beds. The age o f the M i s t Mountain s t r a t a has not been p r e c i s e l y d e t e r m i n e d a l t h o u g h i t i s known t o be L a t e J u r a s s i c t o E a r l y C r e t a c e o u s . In the F e r n i e a r e a a L a t e P o r t l a n d i a n ammonite was 18 found a t the top o f the Moose Mountain Member s u g g e s t i n g a L a t e J u r a s s i c age a t t h a t l o c a l i t y ( N o r r i s , 1959). S i x p l a n t f o s s i l s were c o l l e c t e d from s t r a t a a t E a g l e Mountain and were i d e n t i f i e d by Dr.G. Rouse a t U.B.C. as C o n i o p t e r i s b r e v i f o l a , P t i l o p h y l l u m a r c t i c u m , P i t y o p h y l l u m p h o e n i c o p s i s Cycadospermum oregonense, Pityospermum a n t h r o -c i t i c u m , P t i l o p h y l l u m (Anonozamites) montanense. They are the same s p e c i e s as those found i n the M o r r i s e y F o r m a t i o n a t Grassy Mountain which are c o n s i d e r e d t o be Neocomian-Barremian i n age ( B e l l , 1956). P r e s e n t l y , no p r e c i s e d a t i n g has o c c u r r e d because of a p a u c i t y of good i n d e x f o s s i l s . S t r u c t u r e The major s t r u c t u r a l f e a t u r e s found on the F o r d i n g R i v e r p r o p e r t y i n c l u d e the A l e x a n d e r Creek and G r e e n h i l l s S y n c l i n e s , the F o r d i n g R i v e r A n t i c l i n e , the E r i k s o n F a u l t and numerous unnamed t h r u s t f a u l t s ( F i g u r e 7 ) . The A l e x a n d e r Creek S y n c l i n e , c a l l e d the F o r d i n g S y n c l i n e l o c a l l y , i s c o n t i n u o u s a l o n g the e n t i r e l e n g t h of the E l k V a l l e y C o a l f i e l d . I t o c c u r s t o the e a s t of F o r d i n g R i v e r and r o u g h l y b i s e c t s E a g l e Mountain. T h i s f o l d plunges t o t h e n o r t h w e s t . The e a s t l i m b d i p s a t 35-45 d e g r e e s , whereas the west li m b d i p s a t 20-25 degr e e s . F i g u r e 7 i l l u s t r a t e s s e v e r a l major h i g h - a n g l e t h r u s t f a u l t s t h a t cause e c o n o m i c a l l y i m p o r t a n t r e p e t i t i o n s of c o a l - b e a r i n g s t r a t a . Numerous normal and r e v e r s e f a u l t s f u r t h e r c o m p l i c a t e c o a l e x t r a c t i o n . The G r e e n h i l l s S y n c l i n e o c c u r s on the w e s t e r n s i d e of F o r d i n g R i v e r i n the G r e e n h i l l s Range. T h i s f o l d i s a l s o Figure 7 Genera l i zed geologica l c r o s s sect ion on Eag le Mountain (after Tap l in , 1976) 20 asymmetric w i t h 35-50 degree d i p s on the west l i m b and 10-20 degree d i p s on the e a s t l i m b . T h i s s y n c l i n e i s c h a r a c t e r i z e d by numerous normal f a u l t s . S t r a t a which were deformed by the F o r d i n g Mountain A n t i c l i n e have been eroded by the F o r d i n g R i v e r on the p r o p e r t y . The r i v e r v a l l e y f o l l o w s the E r i k s o n F a u l t , a normal f a u l t which has s t r a t a on the west s i d e downthrown by 330 metres (Pearson and G r i e v e , 1980). Outcrops i n the v a l l e y i n d i c a t e t h a t T r i a s s i c Spray R i v e r F o r m a t i o n and J u r a s s i c - C r e t a c e o u s Kootenay Group sediments have been j u x t a p o s e d . 2.2. EXPLANATION OF TERMS The s t r a t i g r a p h i c s u c c e s s i o n i n the s t u d y a r e a has been d i v i d e d i n t o t h r e e d i s t i n c t u n i t s , r e f e r r e d t o as U n i t s I , I I and I I I . U n i t I i s the lowermost and i s composed of Seams 1, 2 and 3 and a major sandstone i n t e r v a l below 4 Seam. U n i t I I i s composed of a l l the l i t h o l o g i e s from 4 Seam up t o , but e x c l u d i n g , 9 Seam. The uppermost U n i t makes up the remainder o f the sequence from 9 t o 15 seams ( F i g u r e 8 ) . These u n i t s were chosen on the b a s i s of the geometry o f d i s t i n c t i v e sandstone b o d i e s . The c h a r a c t e r i s t i c s o f each u n i t , as d e t e r m i n e d from o u t c r o p and g e o p h y s i c a l l o g s t u d i e s , are d i s c u s s e d and r e l a t e d t o f a c i e s i n the f o l l o w i n g s e c t i o n s . In t h i s d i s c u s s i o n the term " f a c i e s " i s r e f e r r e d t o i n a g e n e t i c sense. F a c i e s as used here r e f e r s t o the p r o d u c t s of a p r o c e s s by which the r o c k s are thought t o have been formed. For 21 from TA PL IN, 1976 This Study 2 < HI CO CO ^ UJ £ SI 6 0 0 m 5 5 0 m 5 0 0 m 4 5 0 m 4 0 0 m 3 5 0 m 3 0 0 m 2 5 0 m 2 0 0 m 150 m 100 m 50 m D A T U M 0 m 14U 14L 13 12 11U 11 9 MY 7 4 2 r = 1 "E" Sandstone 6 3 M I S T M O U N T A I N 6 "D* Sandstone 1 F O R M A T I O N 9 " C " Sandstone 7 "B* Sandstone 1 "A" Sandstone 2 Basa l Sandstone M O R R I S E Y F O R M A T I O N F E R N I E F O R M A T I O N o i 0. < DC O CO LU o < o CO o I < CC Unit III Unit II Unit I Figure 8 G e n e r a l i z e d strat igraphic sect ion of the Kootenay Group (modified from Tapl in , 1976) . 22 example, "channel f a c i e s " r e f e r s t o the p r o d u c t s of f l o w c o n f i n e d t o a cha n n e l (Reading, 1978, p . 4 ) . In t h i s way, s e v e r a l l i t h o l o g i e s can be d e s c r i b e d and r e l a t e d t o one d e p o s i t i o n a l environment. Groups o f f a c i e s t h a t tend t o o c c u r t o g e t h e r a re c a l l e d f a c i e s a s s o c i a t i o n s by Reading (1978, p . 5 ) . By i n t e r p r e t i n g a f a c i e s w i t h r e f e r e n c e t o a d j a c e n t f a c i e s an o v e r a l l e n v i r o n m e n t a l p i c t u r e can be i n t e r p r e t e d . Sequences o f f a c i e s can be r e c o g n i z e d i n v e r t i c a l s e c t i o n s as a s e r i e s of l i t h o l o g i e s g r a d i n g i n t o one a n o t h e r , but bounded a t the top and bottom by a sharp c o n t a c t . The c o n t a c t may r e p r e s e n t an e r o s i v e phase o r an h i a t u s i n d e p o s t i o n (Reading, 1978, p . 5 ) . Two common sequences i n the s t u d y a r e a a re c o a r s e n i n g -upward and f i n i n g - u p w a r d sequences. These sequences are d i s t i n c t i v e and e a s i l y r e c o g n i z e d i n o u t c r o p , c o r e and g e o p h y s i c a l l o g s . They v a r y i n s c a l e from graded beds t o v e r y t h i c k s u c c e s s i o n s o f sediments l a i d down by m i g r a t i n g r i v e r b a r s . T h e i r g r a i n s i z e v a r i a t i o n i s a r e f l e c t i o n o f the f l o w regime i n which they were d e p o s i t e d . For example, a c o a r s e n i n g -upward sequence, such as o c c u r s when a d e l t a or r i v e r s p l a y progrades i n t o a s t a n d i n g body o f w a t e r , i s i n d i c a t i v e o f an i n c r e a s e i n f l o w r a t e . A d e c r e a s e i n f l o w r a t e produces a f i n i n g - u p w a r d sequence. The Wentworth s i z e s c a l e was used f o r the c l a s s i f i c a t i o n of l i t h o l o g i e s based on g r a i n s i z e . The s c a l e i s i n c l u d e d i n Appendix V. The term " i n t e r b u r d e n " i s used t o d e s c r i b e any l i t h o l o g i c a l sequence t h a t o c c u r s between two c o a l seams. 23 The c a l c u l a t i o n of the i n i t i a l peat t h i c k n e s s e s t h a t produced the p r e s e n t c o a l t h i c k n e s s e s was based on the assumption o f a peat t o b i t u m i n o u s c o a l compaction r a t i o o f 6:1 as suggested by S t a c h e t a l . (1982). Peat swamp growth p e r i o d s were c a l c u l a t e d assuming c o n t i n u o u s peat a c c u m u l a t i o n a t a growth r a t e o f 1 mm. a n n u a l l y . T h i s annual growth r a t e was chosen as i n t e r m e d i a t e between the v a l u e s f o r p r e s e n t l y - f o r m i n g temperate (0.5-1 mm/year) and s u b t r o p i c a l (1-1.3 mm./year) peats ( F i s k , 1960). 2.3. LITHOFACIES 2.3.1. Channel D e p o s i t s A l t h o u g h sandstones make up o n l y 15 % o f the M i s t Mountain F o r m a t i o n , they a re the most c o n s p i c u o u s d e p o s i t s i n the sequence. In o u t c r o p they appear t a b u l a r t o l e n t i c u l a r i n shape and range i n t h i c k n e s s from 4 t o 21 metres. As shown i n f i g u r e s 9-13 (Map Pocket) t h e r e i s no c o n c e n t r a t o n of t h i c k e r sandstone b o d i e s i n any one u n i t . However, t h e r e i s a v e r t i c a l v a r i a t i o n i n t he number o f sandstone b o d i e s p r e s e n t . For example, r o u g h l y h a l f o f U n i t I i s made up of s a n d s t o n e s , U n i t I I has a l e s s e r amount than U n i t I and U n i t I I I has the l e a s t amount o f sandstone d e p o s i t s i n the sequence. S t a c k i n g o f sandstone d e p o s i t s i s shown i n f i g u r e 10 (Map Pocket) and a d e f i n i t e d e c r e a s e i n sandstone o c c u r r e n c e can be seen from the base of the M i s t Mountain F o r m a t i o n upwards. Some of the sandstone d e p o s i t s can be t r a c e d l a t e r a l l y a c r o s s the 24 e n t i r e s t u d y a r e a o f f o u r k i l o m e t r e s . Commonly the sandstone d e p o s i t s grade l a t e r a l l y i n t o i n t e r b e d d e d sandstones and s i l t s t o n e s t h a t have been i n t e r p r e t e d as c r e v a s s e s p l a y d e p o s i t s . The sandstones w i t h i n the s t a c k e d sequences v a r y from f i n e -t o c o a r s e - g r a i n e d and are immature l i t h a r e n i t e s . The c o l o r ranges from " s a l t and pepper" l i g h t - g r e y (N7), t o d a r k -g r e y - b r o w n i s h - g r e y (N4-5 YR 4/1) on f r e s h s u r f a c e s . Weathered s u r f a c e s can be l i g h t - t o d a r k - g r e y (N7-N4), b u f f (10 YR 8/2) or r u s t (10 YR 6/6) depending on the m i n e r a l o g i c a l c o m p o s i t i o n . The base o f the sandstone i s c h a r a c t e r i z e d by c o n g l o m e r a t i c " l a g " d e p o s i t s . The l a g d e p o s i t r e p r e s e n t s r e s i d u a l c o n c e n t r a t i o n s o f c o a r s e r sediment accumulated as d i s c o n t i n u o u s l e n s e s i n deeper c h a n n e l s c o u r s . The chance of p r e s e r v a t i o n of th e s e d e p o s i t s i s good because they a re r a p i d l y c o v e r e d by sandy b e d l o a d (Reineck and S i n g h , 1980, p. 266). The l a g i s composed of a r g i l l a c e o u s and s i d e r i t i c p e b b l e s , p l a n t f o s s i l s and f o s s i l i z e d wood molds. The wood molds and a r g i l l a c e o u s fragments can be up t o t h r e e metres i n l e n g t h and the l a g t h i c k n e s s can range from s e v e r a l c e n t i m e t r e s t o one metre. S m a l l - s c a l e l o a d and f l u t e c a s t s o c c u r i n f r e q u e n t l y on the sandstone base. The b a s a l l a g d e p o s i t i s o v e r l a i n by a medium- t o c o a r s e -g r a i n e d sandstone t h a t i s c h a r a c t e r i z e d by medium- t o l a r g e -s c a l e c r o s s - s t r a t i f i c a t i o n (0.5-1.0 m.). The c r o s s - s t r a t i f i c a -t i o n i s p l a n a r o r t r o u g h i n form. The l a r g e - s c a l e c r o s s - s t r a t -i f i c a t i o n changes v e r t i c a l l y i n t o s m a l l - t o medium-scale (0.5 cm.-0.5 m.) c l i m b i n g r i p p l e s and p l a n a r and r i p p l e c r o s s - l a m i n -25 a t i o n s (<l cm.)- Sediment d e f o r m a t i o n o c c u r s a l o n g w i t h the r i p p l e s i n the form o f c o n v o l u t e b e d d i n g , sediment slumping and d i s t u r b a n c e by r o o t growth and b u r r o w i n g . The sandstone d e p o s i t s a re i n t e r p r e t e d as l a t e r a l p o i n t bar a c c r e t i o n d e p o s i t s . The d e p o s i t i o n o f p o i n t b a r s r e s u l t s from the l a t e r a l m i g r a t i o n o f a f l u v i a l system d u r i n g f l o o d s t a g e s ( A l l e n , 1965). The c o a r s e s t sediments are d e p o s i t e d i n the c h a n n e l l a g d e p o s i t and a s u c c e s s i o n o f f i n e r sediments b u i l d s up from sand, s i l t , mud and p e a t . The p r e s e r v a t i o n p o t e n t i a l f o r the f i n e upper sediments i s poor because of the p o s s i b i l i t y of e r o s i o n o c c u r r i n g b e f o r e the next sequence i s d e p o s i t e d (Reineck and S i n g h , 1980, p. 268). 2.3.2. Cr e v a s s e S p l a y D e p o s i t s I n t e r - c h a n n e l b a s i n s e d i m e n t a t i o n i s dominated by f l o o d - g e n e r a t e d p r o c e s s e s . E l l i o t (1974) d i s t i n g u i s h e d t h r e e f l o o d - g e n e r a t e d p r o c e s s e s and t h e i r r e l a t e d s e d i m e n t a r y sequences i n modern f l u v i a l e n v i r o n m e n t s ; overbank f l o o d i n g , c r e v a s s i n g and a v u l s i o n . D u r i n g f l o o d i n g , l e v e e s a r e c r e v a s s e d and f l o o d w a t e r s d e p o s i t t h e i r sediment on the a d j a c e n t f l o o d p l a i n (Coleman, 1969; E l l i o t , 1974; Reineck and S i n g h , 1980, p. 291). The s i z e o f the c r e v a s s e c h a n n e l i s dependant on the r i v e r s i z e and the amount o f exce s s water t h a t must be c h a n n e l l e d o f f . Each c r e v a s s e c h a n n e l has a unique sequence o f s e d i m e n t a r y s t r u c t u r e s t h a t are de t e r m i n e d by the magnitude of the f l o o d and the f l o w c h a r a c t e r i s t i c s ( E l l i o t , 1974) . A f t e r the f l o o d w a t e r s 26 s u b s i d e the c r e v a s s e c h a n n e l s may be abandoned, but o c c a s i o n a l l y the main r i v e r d i s c h a r g e i s d i v e r t e d t h r o u g h the c r e v a s s e s t o a new c o u r s e (Oomkens, 1967; E l l i o t , 1974; Reineck and S i n g h . 1980, p.292). T h i s o c c u r s when the c r e v a s s e o f f e r s a h i g h e r g r a d i e n t advantage than the main c h a n n e l and when the d i r e c t i o n o f b i f u r c a t i o n i s o n l y s l i g h t l y a n g l e d from the main c h a n n e l (Oomkens, 1967). In modern f l o o d p l a i n environments overbank f l o o d i n g o c c u r s e v e r y one o r two y e a r s (Leopold and Wolman, 1957). The s p l a y sediments are d e p o s i t e d i n narrow or broad tongues t h a t t a p e r and f i n e away from the main c h a n n e l (Reineck and S i n g h , 1980, p. 292). The s p l a y d e p o s i t s can range from c e n t i m e t r e s t o metres i n t h i c k n e s s . C r e v a s s e c h a n n e l s commonly e x h i b i t s cour and f i l l s t r u c t u r e s ( E l l i o t , 1974). Rapid f l o w i n l a t e r a l l y r e s t r i c t e d c h a n n e l s produces s m a l l - t o medium-scale p l a n a r and r i p p l e c r o s s - s t r a t i f i c a t i o n . A s h a l l o w i n g of the c h a n n e l and r a p i d s e d i m e n t a t i o n produces graded b e d d i n g , c l i m b i n g r i p p l e s and p l a n a r l a m i n a t i o n s (Reading, 1978, p.39). A f i n i n g - u p w a r d s t o s i l t s t o n e s and r o o t - r i c h mudstones r e f l e c t s waning f l o w and c h a n n e l i n f i l l i n g ( G e r s i b and McCabe, 1981). The p r o x i m a l s p l a y s c o n t a i n some of the c o a r s e b e d l o a d p o r t i o n o f the r i v e r sediment (Walker and Cant, 1980). The c o a r s e r m a t e r i a l i s d e p o s i t e d c l o s e t o the source and the s p l a y t h i n s and f i n e s i n the d i s t a l p o s i t i o n . P r o g r a d a t i o n of s p l a y d e p o s i t s over the f l o o d p l a i n produces a coarsening-upward p r o f i l e ( E l l i o t , 1974). A coarsening-upward p r o f i l e may a l s o 27 i n d i c a t e p r o g r a d a t i o n of s p l a y m a t e r i a l i n t o s t a n d i n g b o d i e s of water on the f l o o d p l a i n . F i g u r e 14 i s an example of g e o p h y s i c a l l o g res p o n s e s i n d i c a t i n g f i n i n g - u p w a r d p r o x i m a l s p l a y s and coarsening-upward d i s t a l s p l a y s . On E a g l e M ountain, c r e v a s s e s p l a y d e p o s i t s a re abundant i n a l l u n i t s of the M i s t Mountain F o r m a t i o n . They make up a major p o r t i o n of the overbank f a c i e s . C r e v a s s e s p l a y d e p o s i t s a re most e v i d e n t a d j a c e n t t o the cha n n e l sequence i n the 5 t o 7 seam i n t e r v a l . I s o l i t h maps ( F i g u r e s 18, 21, 25, 27, 37) i l l u s t r a t e p r o t r u d i n g sand l o b e s p r o x i m a l t o the c h a n n e l s . These l o b e s have been i n t e r p r e t e d as s p l a y d e p o s i t s on the b a s i s o f t h e i r f a c i e s a s s o c i a t i o n s and s e d i m e n t o l o g i c a l c h a r a c t e r i s t i c s . The s p l a y d imensions v a r y w i t h the s i z e of the cha n n e l d e p o s i t s . The s m a l l e s t s p l a y s a re a s s o c i a t e d w i t h "B" Channel d e p o s i t s ( F i g u r e 2 1 ) . They ex t e n d 500-700 metres from the chan n e l margin and are a p p r o x i m a t e l y one k i l o m e t e r wide. The l a r g e s t s p l a y l o b e s a re a s s o c i a t e d w i t h "D" Channel d e p o s i t s ( F i g u r e 2 7 ) . The s a n d s t o n e - s i l t s t o n e l o b e s e x t e n d 1-4 k i l o m e t e r s from the edge o f the ch a n n e l and are 4-6 k i l o m e t e r s wide. From s t u d y i n g the i n t e r n a l c h a r a c t e r i s t i c s of t h e s e d e p o s i t s , two s p l a y t y p e s were r e c o g n i z e d ; p r o x i m a l s p l a y s and d i s t a l s p l a y s . P r o x i m a l S p l a y D e p o s i t s P r o x i m a l s p l a y d e p o s i t s are composed of f i n e - g r a i n e d s a n d s t o n e s , s i l t s t o n e s and mudstones t h a t more commonly Figure 14 Represen ta t i ve Gamma ray r e s p o n s e s for C h a n n e l , P rox ima l s p l a y , and D is ta l s p l a y . 0 0 29 f i n e - u p w a r d than coarsen-upwards. The sequences average 3 metres i n t h i c k n e s s and r a r e l y , 5 metre u n i t s o c c u r . The s p l a y d e p o s i t s are most e v i d e n t near sandstone Channels "A" t o "E" where they o c c u r i n s t a c k e d sequences up t o f i f t y metres t h i c k . The sandstones are b r o w n i s h - g r e y (5 YR 4/1), t o d a r k - g r e y (N3) i n o u t c r o p and are o f t e n r u s t y - b r o w n (10 YR 6/6) , and c o l o r - b a n d e d . On f r e s h s u r f a c e s they are s a l t and pepper (N7), c o l o r e d . The base of the f i n i n g - u p w a r d sequence i s e r o s i o n a l and a b r u p t where c r e v a s s e c h a n n e l l i n g has s c o u r e d i n t o p o i n t bar d e p o s i t s or l e v e e muds and p e a t s . Remnants of t h e s e u n d e r l y i n g d e p o s i t s a r e p r e s e r v e d as s i l t and mud r i p - u p c l a s t s and c o a l s p a r . Bedding i n the lower p a r t o f the sandstones i s i n the form of s m a l l - t o medium-scale p l a n a r and r i p p l e c r o s s - s t r a t i f i c a -t i o n . The lower sandstones grade upward t o s i l t y sandstones and s i l t s t o n e s t h a t show c l i m b i n g r i p p l e s and p l a n a r l a m i n a t i o n s . The uppermost s i l t s t o n e s are commonly d i s t u r b e d by s o f t - s e d i m e n t d e f o r m a t i o n i n the form of c o n v o l u t e b e d d i n g , slump and d e w a t e r i n g s t r u c t u r e s and b i o t u r b a t i o n . P l a n t a c t i v i t y i s i n d i c a t e d a t the top o f the s p l a y d e p o s i t s by r o o t m o t t l i n g s i n i n t e r b e d d e d s i l t s t o n e s and mudstones. D i s t a l S p l a y D e p o s i t s D i s t a l s p l a y d e p o s i t s , t h a t more commonly c o a r s e n - than f i n e - u p w a r d s , are composed of i n t e r b e d d e d sandstone and s i l t s t o n e w i t h minor mudstone. These d e p o s i t s are 1-3 metres i n t h i c k n e s s , but can be s t a c k e d i n sequences of up t o 10 metres. 30 Gamma r a y l o g r esponses are the c l e a r e s t i n d i c a t o r s of d i s t a l s p l a y s ( F i g u r e 14). D i s t a l s p l a y d e p o s i t s commonly o v e r l i e l a m i n a t e d o r g a n i c c l a y s and s i l t s of swamp or pond o r i g i n . The sandstones of d i s t a l s p l a y d e p o s i t s are v e r y f i n e - t o f i n e - g r a i n e d and are commonly s i l t y . R i p p l e and p l a n a r l a m i n a t i o n s and f l a s e r and l e n t i c u l a r bedding are the most common se d i m e n t a r y s t r u c t u r e s p r e s e n t . The i n t e r b e d d e d sandstones and s i l t s t o n e s are b o t h b r o w n i s h - g r e y (5 YR 4/1), on weathered s u r f a c e s and l i g h t grey (N7), on f r e s h s u r f a c e s . C o l o r b anding o c c u r s where s i d e r i t e c o n c r e t i o n s are p r e s e n t i n s i l t s t o n e beds. P l a n t f o s s i l s a re abundant on bedding p l a n e s . Sediment m o t t l i n g r e s u l t i n g from b u r r o w i n g and r o o t l e t p e n e t r a t i o n i s e v i d e n t i n some s t r a t a . 2.3.3. N a t u r a l Levee D e p o s i t s Levees are wedge-shaped sediment r i d g e s t h a t b u i l d up a l o n g c h a n n e l edges from the d e p o s i t i o n of m a t e r i a l c a r r i e d by w a t e r s t h a t top the banks ( E l l i o t , 1974; Reineck and S i n g h , 1980, p. 299). The c o a r s e r f r a c t i o n of the sediment i s d e p o s i t e d near the c h a n n e l as f l o w v e l o c i t y and competence d e c r e a s e . The g r a i n s i z e and r a t e of d e p o s i t i o n d e c r e a s e away from the c h a n n e l as w a t e r s f l o w i n t o the f l o o d b a s i n (Reineck and S i n g h , 1980, p. 299). Because l e v e e s are n a t u r a l l y l a t e r a l l y r e s t r i c t e d , t hey are a minor component of the F o r m a t i o n . They o c c u r above, or a d j a c e n t t o , c h a n n e l d e p o s i t s . Where p r e s e n t , l e v e e s are composed of s i l t y sandstones and sandy s i l t s t o n e s t h a t f i n e - u p -31 ward t o p l a n a r - l a m i n a t e d , r o o t - r i c h mudstones and c o a l s . The s i l t s t o n e beds are c e n t i m e t r e s t o 3 metres i n t h i c k n e s s . The sandstones and s i l t s t o n e s appear s i m i l a r i n o u t c r o p . They a r e b r o w n i s h - g r e y (5 YR 4/1), t o d a r k - g r e y (N3), on weathered s u r f a c e s and medium-grey (N5), on f r e s h s u r f a c e s . C o l o r - b a n d i n g o c c u r s where i r o n c o n c e n t r a t i o n s are h i g h and s i d e r i t e has p r e c i p i t a t e d i n the form of l e n s e s and c o n c r e t i o n s . The most common sed i m e n t a r y s t r u c t u r e s a r e p a r a l l e l and r i p p l e l a m i n a t i o n s . S m a l l - s c a l e p l a n a r c r o s s b e d d i n g and c l i m b i n g r i p p l e s are o c c a s i o n a l l y p r e s e n t . Sediment d e f o r m a t i o n s t r u c t u r e s i n the upper p o r t i o n of the s i l t s t o n e s i n c l u d e c o n v o l u t e l a m i n a t i o n s , slump s t r u c t u r e s and b i o t u r b a t i o n . F o s s i l i z e d p l a n t remains are abundant and t r e e stumps i n v e r t i c a l growth p o s i t i o n s o c c u r i n i n t e r b e d d e d s i l t s t o n e s and mudstones. C o n t a c t s of t h e s e l i t h o l o g i e s a r e g r a d a t i o n a l or s h a r p . 2.3.4. F l o o d B a s i n D e p o s i t s F l o o d b a s i n s or p l a i n s are l o w - l y i n g , f l a t , p o o r l y - d r a i n e d a r e a s a d j a c e n t t o a c t i v e o r abandoned r i v e r c h a n n e l s (Reineck and S i n g h , 1980, p. 295). S e d i m e n t a t i o n i n the f l o o d b a s i n s i s by s e t t l i n g o f suspended f i n e - g r a i n e d m a t e r i a l from overbank f l o o d w a t e r s . Overbank f l o o d i n g may o c c u r e v e r y one or two y e a r s r e s u l t i n g i n d e p o s i t s o n l y m i l l i m e t r e s t h i c k ( Leopold and Wolman, 1957; L e e d e r , 1978; Reineck and S i n g h , 1980, p. 295). The c o a r s e r sediment from the overbank f l o w s i s d e p o s i t e d i n c l o s e p r o x i m i t y t o the c h a n n e l and c o n t r i b u t e s t o l e v e e and 32 s p l a y development. F l o o d b a s i n d imensions are dependant on the s i z e and type o f c h a n n e l p r e s e n t (Reineck and S i n g h , 1980, p. 295).. T h i n , e l o n g a t e d f l o o d b a s i n d e p o s i t s are formed by r i v e r s t h a t have r a p i d r a t e s o f l a t e r a l m i g r a t i o n , such as b r a i d e d c h a n n e l s (Reineck and S i n g h , 1980, p. 295). T h i c k e r , w i d e r f l o o d b a s i n s a r e a s s o c i a t e d w i t h r i v e r s t h a t do not have e x t e n s i v e l a t e r a l l y s h i f t i n g p a t t e r n s . F l o o d b a s i n d e p o s i t s on E a g l e Mountain can be d i f f e r e n t i a t e d i n t o t h r e e t y p e s ; overbank sheet f l o w d e p o s i t s , swamp d e p o s i t s and pond d e p o s i t s . Overbank sheet f l o w s o c c u r d u r i n g f l o o d i n g e v e n t s when f l o o d w a t e r s top the l e v e e s w i t h o u t the a i d o f c r e v a s s e breaches (Coleman, 1969). Coarse sediment i s d e p o s i t e d on the l e v e e s and f i n e r s i l t and c l a y are c a r r i e d t o d i s t a l p o s i t i o n s ( E l l i o t , 1974). On E a g l e Mountain sheet f l o w d e p o s i t s are c h a r a c t e r i z e d by s e d i m e n t a r y f e a t u r e s t h a t formed when l i g h t - t o medium-grey (N7-N5), s i l t s and c l a y s s e t t l e d out of s u s p e n s i o n . S o f t - s e d i m e n t s l u m p i n g commonly causes c o n v o l u t e l a m i n a t i o n s . O c c a s i o n a l l y , r i p - u p c l a s t s and r i p p l e marks are p r e s e n t i n sandy and s i l t y i n t e r c a l a t i o n s i n d i c a t i n g c u r r e n t s c o u r i n g (Reineck and S i n g h , 1980, p. 298-301). F o s s i l i z e d p l a n t and v e r t e b r a t e remains may a l s o o c c u r i n sheet f l o w d e p o s i t s . P y r i t e and s i d e r i t e n o d u l e s and c o n c r e t i o n s are common, perhaps i n d i c a t i n g r e d u c i n g c o n d i t i o n s i n s o i l p r o f i l e s . T h i c k l y v e g e t a t e d peat swamps form i n f l o o d b a s i n s when c l i m a t i c and s u b s i d e n c e c o n d i t i o n s are f a v o r a b l e . Humid c l i m a t e s p r e v e n t d r y i n g out o f the f l o o d p l a i n and a l l o w v e g e t a t e d a r e a s 33 t o d e v e l o p . Peat swamps p r e s e n t l y form i n humid-temperate, s u b - t r o p i c a l and t r o p i c a l c l i m a t e s . T r o p i c a l c l i m a t e s f a v o r f o r e s t swamps over r e e d and moss swamps. The abundant m o i s t u r e and warm te m p e r a t u r e s a l l o w t r e e s t o grow t o 30 metres i n h e i g h t i n a r e l a t i v e l y s h o r t time p e r i o d (7-9 y e a r s ) , whereas i n the h a r s h e r c o n d i t i o n s o f temperate r e g i o n s the same growth p e r i o d y i e l d s t r e e s o n l y 5-6 metres h i g h ( T e i c h m u l l e r and T e i c h m u l l e r , 1982, p. 6 ) . To form peat i t i s n e c e s s a r y t h a t groundwater s t a g n a t e s a t or near ground l e v e l p r e v e n t i n g the d e c o m p o s i t i o n o f p l a n t m a t e r i a l . T h i s most f r e q u e n t l y o c c u r s on f l a t p l a i n s a l o n g s e a c o a s t s . P e a t s t h a t a re c l i m a t i c a l l y - c o n d i t i o n e d and o c c u r on c o a s t a l p l a i n s where t h e r e i s a r e g i o n a l c o n t r o l on ground water l e v e l are r e f e r r e d t o as p a r a l i c bogs. They are d i s t i n g u i s h e d from l i m n i c ( i n l a n d ) low moors t h a t form i n t o p o g r a p h i c d e p r e s s i o n s where s t a g n a n t water r e q u i r e m e n t s a re met. P a r a l i c p e a t s t h a t d e v e l o p on the d i s t a l p o r t i o n s of d e l t a s i n temperate and s u b - t r o p i c a l a r e a s may be t r e e l e s s sedge-reed swamps or may be a c o m b i n a t i o n o f re e d swamp and f o r e s t e d hummocks. P r e s e n t l y , mangrove f o r e s t s are the dominant v e g e t a t i o n t y p e s i n t r o p i c a l c o a s t a l swamps ( T e i c h m u l l e r and T e i c h m u l l e r , 1982). R e g r e s s i o n of the sea a l l o w s the mangrove and reed swamps t o advance seaward as the c o a s t l i n e p r o g r a d e s . F i r e s p l a y an i m p o r t a n t r o l e i n r e d u c i n g f o r e s t swamps t o re e d and moss swamps. R a r e l y do swamps c o n t a i n e x c l u s i v e l y one type of v e g e t a t i o n . R a t h e r , they are m i x t u r e s o f moss, herbaceous and arb o r a c e o u s v e g e t a t i o n . 34 L a c u s t r i n e d e p o s i t s i n the M i s t Mountain F o r m a t i o n a re most commonly a s s o c i a t e d w i t h peat swamp d e p o s i t s . They are found above, below, i n , and a d j a c e n t t o c o a l seams i n the s t r a t i g r a p h i c sequence. Because of t h i s c l o s e a s s o c i a t i o n , the l a m i n a t e d c l a y s and s i l t s a r e h i g h l y o r g a n i c . They are d a r k - g r e y t o b l a c k (N3-N1), on f r e s h s u r f a c e s and brown t o d a r k - g r e y (5 YR 4/1-N3), on weathered s u r f a c e s . C o a l y l a m i n a t i o n s and p l a n t f o s s i l s a r e abundant. Bedding p l a n e s a re co v e r e d w i t h f i n e l y d i s s e m i n a t e d f o s s i l p l a n t f r a g m e n t s , o c c a s i o n a l l y l a r g e enough t o be i d e n t i f i e d as stems o r l e a v e s , (Appendix I ) . T h i n (<lcm.), p a r a l l e l l a m i n a t i o n s a re the commonest s e d i m e n t a r y f e a t u r e s . S o f t - s e d i m e n t d e f o r m a t i o n s t r u c t u r e s , r o o t l e t s and r i p p l e s a r e o c c a s i o n a l l y p r e s e n t . When an i n f e r r e d pond d e p o s i t o c c u r s a d j a c e n t t o or beneath a c o a l seam, a g r a d a t i o n a l c o n t a c t e x i s t s over a s h o r t l a t e r a l d i s t a n c e , (1-2 m e t r e s ) . Pond d e p o s i t s o v e r l y i n g c o a l seams have a b r u p t c o n t a c t s . The p r o p o r t i o n o f mudstone t o c o a l was examined f o r the t h r e e major u n i t s . I n U n i t I , t h e r e a re 1.6 metres o f mudstone f o r e v e r y metre of c o a l . In U n i t I I , the r a t i o was found t o be 2.8 metres o f mudstone t o ev e r y metre of c o a l . The r a t i o i n U n i t I I I was 1.5 metres mudstone t o e v e r y metre of c o a l . The r e l a t i v e abundance o f the pond d e p o s i t s r e f l e c t s the cha n g i n g d e p o s i t i o n -a l e nvironments of the t h r e e U n i t s . F l o o d b a s i n pond d e p o s i t s a re commonly i n t e r b e d d e d w i t h overbank sheet f l o w d e p o s i t s and d i s t a l s p l a y d e p o s i t s . In th e s e i n s t a n c e s , s h a l l o w ponds were a b r u p t l y i n f i l l e d by l i g h t e r 35 c o l o r e d s i l t s and muds from f l o o d w a t e r s . O c c a s i o n a l l y , s p l a y s p r o g r a d i n g i n t o ponds caused coarsening-upward d e l t a sequences t o be formed. 2.4. LITHOFACIES DESCRIPTIONS AND SEDIMENTOLOGY 2.4.1. U n i t I C h a r a c t e r i s t i c s The lowermost l i t h o s t r a t i g r a p h i c package c o m p r i s e s C o a l Seams 1, 2 and 3, a l a t e r a l l y e x t e n s i v e sandstone body, d e s i g n a t e d as "A" Sandstone and an i n t e r b e d d e d s a n d s tone, s i l t -s t one and mudstone sequence. The t h i c k n e s s o f the U n i t v a r i e s from 22 metres i n the southwest t o 70 metres i n the n o r t h and t h i n s t o the s o u t h and west. C o a l Seam 1, a t the base of the U n i t , i s u n d e r l a i n by the Moose Mountain Member of the M o r r i s e y F o r m a t i o n , or the " B a s a l Sandstone" as i t i s c a l l e d l o c a l l y . A l t h o u g h the B a s a l Sandstone i s not i n c l u d e d i n U n i t I , i t was examined f o r the purpose of e s t a b l i s h i n g i t s d e p o s i t i o n a l environment. B a s a l Sandstone The r e s i s t a n t Moose Mountain Member i s a f i n e - t o medium-g r a i n e d , mature s u b l i t h a r e n i t e . In o u t c r o p i t i s w e l l s o r t e d , w e l l i n d u r a t e d and c o n t r a s t s markedly w i t h the o v e r l y i n g r e c e s s i v e mudstones and c o a l s o f U n i t I of the M i s t Mountain F o r m a t i o n . The commonest s e d i m e n t a r y f e a t u r e s observed i n c l u d e s m a l l - t o l a r g e - s c a l e t r o u g h c r o s s b e d d i n g . Less f r e q u e n t s m a l l -36 t o medium-scale p l a n a r and t a b u l a r c r o s s b e d d i n g o c c u r . P l a n a r l a m i n a t i o n s , a r g i l l a c e o u s r i p - u p c l a s t s and s a n d - f i l l e d burrows a l s o o c c u r . S h a l e y t o c o a l y i n t e r b e d s o c c u r i n f r e q u e n t l y as shown i n f i g u r e 15. O f t e n a s s o c i a t e d w i t h t h e s e i n t e r b e d s i s f i n e - g r a i n e d p y r i t e i n the form of cubes o r fr a m b o i d s ( F i g u r e 1 5 ) . In t h i n - s e c t i o n the B a s a l Sandstone has a q u a r t z and c h e r t framework w i t h minor carbonaceous fragments. M u s c o v i t e , c a r b o n a t e and opaque m i n e r a l s a re p r e s e n t i n minor amounts w i t h z i r c o n and mica o c c u r r i n g i n t r a c e amounts. The m a t r i x and cement are p r e d o m i n a n t l y s i l i c e o u s and f e r r u g i n o u s m i n e r a l s . A more d e t a i l e d m i n e r a l o g i c a l summary i s p r o v i d e d i n Appendix I I . T h i c k n e s s d e t e r m i n a t i o n s were not c a r r i e d out f o r t h i s sandstone u n i t as the lower c o n t a c t was not observ e d i n o u t c r o p . I t i s known t o be 12 t o 36 metres t h i c k i n t h i s a r e a from r o t a r y and diamond d r i l l h o l e i n f o r m a t i o n . The upper c o n t a c t w i t h the M i s t Mountain F o r m a t i o n i s conformable and ab r u p t where i t i s observe d i n o u t c r o p . The gamma r a y g e o p h y s i c a l response i s shown i n f i g u r e s 15 and 16. The low gamma r a y response i s c h a r a c t e r i s t i c o f t h i s c l e a n q u a r t z o s e sandstone and i n d i c a t e s a l a c k o f a r g i l l a c e o u s m a t e r i a l . C o a l Seam One In o u t c r o p C o a l Seam 1 a b r u p t l y o v e r l i e s the M o r r i s e y F o r m a t i o n and v a r i e s i n t h i c k n e s s from l e s s than one metre t o f o u r metres. Seam 1 t h i n s t o the s o u t h e a s t . In o u t c r o p i t i s o f t e n a r g i l l a c e o u s and o x i d i z e d , but more commonly i s a s h i n y , F i g u r e 1 5 D D H 1 7 5 8 S E D I M E N T S O F U N I T I 38 F i g u r e 1 6 D D H 1 6 2 8 S E D I M E N T S O F U N I T I 39 b r i t t l e b l a c k c o a l ( N l ) , w i t h one or two c o n s p i c u o u s c l e a t d i r e c t i o n s . The predominant l i t h o t y p e i s v i t r a i n . In comparison t o the r e s i s t a n t , u n d e r l y i n g B a s a l Sandstone, Seam 1 i s r e c e s s i v e and b l o c k y t o s h e a r e d . The c o n t a c t w i t h the B a s a l Sandstone i s conformable and a b r u p t i n o u t c r o p but has been obser v e d as g r a d a t i o n a l i n d r i l l c o r e . The gamma r a y response ( F i g u r e 15) shows an a b r u p t c o n t a c t from c l e a n q u a r t z sandstone t o Seam 1, whereas the response shown i n f i g u r e 16 e x h i b i t s a g r a d u a l t r a n s i t i o n from q u a r t z sandstone through muddy s i l t s t o n e t o c o a l . Seam 1 i s a c l e a n c o a l w i t h few s p l i t s . Seams 1 and 2 are s e p a r a t e d by a c o a l y s h a l e or s i l t s t o n e i n t e r v a l t h a t ranges from one t o t h r e e metres i n t h i c k n e s s . T h i s f i n e - g r a i n e d s i l t s t o n e commonly e x h i b i t s p l a n a r l a m i n a t i o n s , r i p p l e l a m i n a t i o n s , r o o t l e t s and e v i d e n c e o f b u r r o w i n g . I t u s u a l l y weathers medium- t o d a r k - g r e y (N5-N3). C o a l Seam Two C o a l Seam 2 i s composed of an upper and lower seam s e p a r a t e d by a mudstone p a r t i n g i n the n o r t h w e s t and s o u t h e a s t s e c t o r s of the s t u d y a r e a . The p a r t i n g , which v a r i e s from two t o t h r e e metres i n t h i c k n e s s i n the n o r t h w e s t , a p p a r e n t l y p i n c h e s out t o the e a s t i n the n o r t h e r n and c e n t r a l s e c t o r s . I t r e a p p e a r s i n the s o u t h e a s t where i t reaches a p p r o x i m a t e l y two metres i n t h i c k n e s s . The seam i s s h a l e y and b l o c k y t o sheared. The p a r t i n g i s u s u a l l y a d a r k - g r e y t o b l a c k (N3-N1), carbonaceous s h a l e w i t h abundant p l a n t f o s s i l s and p l a n a r l a m i n a t i o n s . 40 Sandstone "A" T h i s r e s i s t a n t sandstone o c c u r s above 2 Seam or i s s e p a r a t e d from i t by s i l t s t o n e and mudstone beds. In the nor t h w e s t and c e n t r a l s e c t o r s of the study a r e a Sandstone "A" l i e s d i r e c t l y upon 2 Seam w i t h an e r o s i o n a l c o n t a c t ( F i g u r e 1 7 ) . To the e a s t and s o u t h the sandstone i s r e p l a c e d by i n t e r b e d d e d sandstone w i t h minor mudstone i n t e r b e d s . The sandstone's l a t e r a l d i s t r i b u t i o n i s shown i n f i g u r e s 9-13 (Map P o c k e t ) . The i s o l i t h map f o r t h i s sandstone was used t o determine the o v e r a l l d i r e c t i o n of the sandstone body. The parameter c o n t o u r e d was the t o t a l amount o f sandstone between C o a l Seams 2 and 4. ( F i g u r e 18) . In the n o r t h e r n s e c t i o n o f the st u d y a r e a , t h e r e a re two main sandstone b o d i e s , one above and one below C o a l Seam 3. The lower sandstone ranges from 12 metres i n t h i c k n e s s i n the west t o 0 i n the e a s t and d i v i d e s i n t o an upper 12 metre and a lower 9 metre s i l t s t o n e s p l i t i n the n o r t h - c e n t r a l a r e a . These d i s t i n c t s p l i t s may r e p r e s e n t a l a t e r a l s h i f t i n g o f the a c t i v e c h a n n e l or more l i k e l y r e p r e s e n t the lower main c h a n n e l and upper l e v e e - c r e v a s s e s p l a y d e p o s i t s . The second major sandstone u n i t , above C o a l Seam 3, i s d i s t i n c t from the lower sandstone u n i t because of the presence of 3 Seam ( F i g u r e 9, Map P o c k e t ) . However, i n the c e n t r a l and s o u t h e r n s e c t o r s of the st u d y a r e a , when 3 Seam i s a b s e n t , d i f f -e r e n t i a t i o n o f the sandstone u n i t s i s d i f f i c u l t . The sandstone u n i t s a re the main components of the 2 t o 4 Seam i n t e r v a l i n the n o r t h , c e n t r a l and e a s t e r n s e c t o r s , but are r e p l a c e d by i n t e r -0. E O LITHOLOQY & GRAIN SIZE CL 3 VF F M I I I I L _ STRUCTURE REMARKS 1 9 0 -180 -170 -160 -150 -140 -1 3 0 -120 -1 1 0 -100 90 80 -70 -60 -50 -40 -30 4 20 10 0 wmmmtm BP un 'A* S a n d s t o n e C h a n n e l f l oo r S e a m 2 Seam 1 F i g u r e 17 C L O D E C R E E K T R A V E R S E 1 - 2 , Sediments of Unit I 42 bedded sandstone and s i l t s t o n e i n the s o u t h e a s t and s o u t h -c e n t r a l a r e a s . The i s o l i t h map ( F i g u r e 18) i l l u s t r a t e s a t o t a l sandstone t h i c k n e s s o f 25 metres t r e n d i n g n o r t h w e s t - s o u t h e a s t t h r o u g h the c e n t r a l a r e a and t h i n n i n g t o the southwest and n o r t h e a s t . In o u t c r o p the sandstone u n i t s a r e r e s i s t a n t , c l i f f - f o r m i n g l i t h a r e n i t e s . They a re " s a l t - a n d - p e p p e r " c o l o r e d (N7), and show some f e r r u g i n o u s s t a i n i n g . Where sandstone i s i n c o n t a c t w i t h Seam 2 the c o n t a c t i s ab r u p t t o e r o s i o n a l w i t h abundant c o a l spar a t the c o n t a c t . S m a l l - t o l a r g e - s c a l e c l i m b i n g r i p p l e t r a i n s and t a n g e n t i a l p l a n a r c r o s s b e d s a re common. C o a l y c l a s t s and p l a n t f o s s i l s a r e abundant a l o n g bedding p l a n e s . C o n v o l u t e bedding and slump s t r u c t u r e s i n d i c a t e d e f o r m a t i o n o f sandstone beds p r i o r t o l i t h i f i c a t i o n . A r g i l l a c e o u s r i p - u p c l a s t s and s i d e r i t e c o n c r e t i o n s commonly o c c u r i n thes e u n i t s . A t y p i c a l "A" Sandstone gamma r a y response i s i l l u s t r a t e d i n f i g u r e 16. The lower c o n t a c t of the sandstone i s abrupt and the s h i f t t o the l e f t i n r e l a t i o n s h i p t o the u n d e r l y i n g s i l t -s t o ne i n d i c a t e s the l e s s a r g i l l a c e o u s n a t u r e of the sandstone. F i g u r e 15 shows the same sandstone w i t h a h i g h e r c l a y c o n t e n t and c o n s e q u e n t l y a h i g h e r gamma r a y re s p o n s e . These sandstones f i n e - u p w a r d i n t o an i n t e r b e d d e d sandstone and s i l t s t o n e i n t e r v a l t h a t shows an i n c r e a s i n g gamma r a y re s p o n s e . C o a l Seam Three C o a l Seam 3 i s a s h a l e y c o a l t h a t o c c u r s i n the n o r t h e r n s e c t o r s o f the stu d y a r e a . I t i s a p p r o x i m a t e l y one and a h a l f metres t h i c k and i s v e r y r e c e s s i v e . I t i s composed of carbona-43 N I N E T C H A N N E L S A N D S T O N E [! : 1 0 - 1 0 m e t r e s l i l l l l l 1 0 - 2 0 m e t r e s Bill 2 0 - 2 5 m e t r e s WMM > 25 m e t r e s 8 « R a w c o a l a s h c o n t e n t (weight %) ' " 4 C o a l s e a m 2 t h i c k n e s s (met res ) D iamond and ro ta ry drill ho les * H o l e s u s e d for c r o s s s e c t i o n s o C o r e d h o l e s 500 Figure 18 "A" channel isolith map and Coa l S e a m 2 i s o p a c h map 44 ceous s h a l e and s h a l e y c o a l w i t h abundant f o s s i l p l a n t fragments on bedding p l a n e s . Because o f i t s h i g h mud c o n t e n t , the c o a l seam i s d i f f i c u l t t o d i s t i n g u i s h i f t h e r e a re r o o f and f l o o r mudstones p r e s e n t . T h i s seam i s not p r e s e n t i n the c e n t r a l and s o u t h e r n s e c t o r s and i s r e p l a c e d by i n t e r b e d d e d sandstones and s i l t s t o n e s . S a n d s t o n e - S i l t s t o n e I n t e r b u r d e n The i n t e r b e d d e d sandstone and s i l t s t o n e u n i t between Coal Seams 3 and 4 v a r i e s i n t h i c k n e s s from 10 metres i n the w e s t e r n s e c t o r t o 21 metres i n the s o u t h e a s t e r n a r e a . I t a l s o t h i c k e n s t o 23 metres i n the n o r t h - c e n t r a l r e g i o n and t h i n s t o 10 metres i n t he n o r t h e a s t . In o u t c r o p , the s i l t y sandstone beds are f i n e -t o medium-grained and d a r k - g r e y (N3), and r e c e s s i v e . They e x h i b i t p l a n a r and t a n g e n t i a l c r o s s b e d d i n g , slump s t r u c t u r e s and c o a l y l e n s e s . B a s a l d e p o s i t s i n c l u d e r i p - u p c l a s t s and l o a d c a s t s . The c o a l y s i l t s t o n e beds a r e f i n e - g r a i n e d and d a r k - g r e y (N3), w i t h p l a n a r and r i p p l e l a m i n a t i o n s . Slump s t r u c t u r e s , r i p - u p c l a s t s and c o n v o l u t e l a m i n a t i o n s i n d i c a t e a h i g h energy d e p o s i t i o n a l environment. F o s s i l i z e d p l a n t f r a g m e n t s , r o o t l e t s and burrows a r e found i n abundance on upper s i l t s t o n e beds. I n t e r b e d d e d sandstone and s i l t s t o n e o c c u r i n f i n i n g - u p w a r d s e t s of 2 t o 3 metres i n t h i c k n e s s and g i v e a jagged gamma r a y re s p o n s e . The lower c o n t a c t w i t h the "A" Sandstone i s a g r a d a t i o n a l , f i n i n g - u p w a r d c o n t a c t , as i s the upper c o n t a c t . These u n i t s f i n e - u p w a r d i n t o the c a r b o n a c e o u s , b l a c k ( N l ) , muddy s i l t s t o n e f l o o r of 4 Lower (4L) Seam. The s i l t s t o n e i s composed of q u a r t z , c h e r t and carbonaceous m a t e r i a l . The framework g r a i n s 45 a r e surrounded by a f e r r u g i n o u s m a t r i x and cement. F o s s i l p l a n t m a t e r i a l i s abundant and the p r i m a r y s e d i m e n t a r y s t r u c t u r e s a r e p l a n a r l a m i n a t i o n s . The gamma r a y response i s t y p i c a l l y i n t e r m e d i a t e t o h i g h , dependant on the amount of c o a l y m a t e r i a l p r e s e n t . More c o a l y m a t e r i a l causes an i n t e r m e d i a t e t o h i g h r esponse ( F i g u r e 1 9 ) . 2.4.2. U n i t I Sedimentology In s t u d y i n g the r e g i o n a l s t r a t i g r a p h y and s e d i m e n t o l o g y o f the s o u t h e a s t c o a l f i e l d s , G i b s o n and Hughes (1981) have proposed d e p o s i t i o n a l s e t t i n g s f o r the F e r n i e , M o r r i s e y , M i s t Mountain and E l k F o r m a t i o n s . R e g i o n a l l y , Hamblin and Walker (1979) and Hughes (1981) agree t h a t the F e r n i e and M o r r i s e y F o r m a t i o n l i t h o f a c i e s a r e comparable t o sequences produced i n modern, wave-dominated d e l t a s . They use the Sao F r a n c i s c o R i v e r of B r a z i l and the Rhone R i v e r o f France as examples o f modern a n a l o g i e s . The Rhone R i v e r has been e x t e n s i v e l y s t u d i e d by Oomkens (1967) and W r i g h t and Coleman (1973) . U s i n g t h e s e a n a l o g i e s , the F e r n i e F o r m a t i o n i s r e g a r d e d as r e p r e s e n t i n g o f f s h o r e p r o d e l t a sediments (Hamblin and Walker, 1979; G i b s o n and Hughes, 1981). The lower F e r n i e s h a l e s and s i l t s t o n e s a re c o n s i d e r e d marine t u r b i d i t e s and the upper c o a r s e r - g r a i n e d sediments storm d e p o s i t s i n a n e a r s h o r e l o c a t i o n (Hamblin and Walker, 1979). O v e r l y i n g the near shore d e p o s i t s are sandstones of t h e Weary Ridge Member. G i b s o n and Hughes (1981) i n t e r p r e t t h e s e p l a n a r t a b u l a r and p a r a l l e l c r o s s - s t r a t i f i e d sandstones as upper s h o r e f a c e and f o r e s h o r e 46 F igure 19 ODH 1628 S e d i m e n t s of Unit II 47 beach d e p o s i t s . The r e s i s t a n t sandstone of the Moose Mountain Member has been i n t e r p r e t e d as a b r a i d e d stream d e p o s i t by Hamblin and Walker (1979) and as backshore and b e a c h - r i d g e and dune d e p o s i t s by Gi b s o n and Hughes (1981). My o b s e r v a t i o n s o f the sandstone c h a r a c t e r i s t i c s and the a p p l i c a t i o n o f c r i t e r i a from Harms e t a l . (1975), Walker (1980), Reineck and Singh (1980) and E l l i o t (1978), l e a d t o c o n c u r r e n c e w i t h the i n t e r p r e t a t i o n of Gi b s o n and Hughes (1981). The c h a r a c t e r i s t i c s o f the Moose Mountain Member sandstone a r e not d i s s i m i l a r t o th o s e found i n b e a c h - r i d g e and dune complexes on the c o a s t o f N a y a r i t i n w e s t e r n Mexico (Curray e t a l . , 1969). The N a y a r i t c o a s t l i n e i s p r o g r a d a t i o n a l , w i t h 250 p a r a l l e l beach r i d g e s r u n n i n g 225 k i l o m e t r e s a l o n g the c o a s t . The r i d g e s a r e b e l i e v e d by C u r r a y e t a l . (1969) t o be i n i t i a t e d by wave a c t i o n . As p r o g r a d a t i o n c o n t i n u e s , wind p l a y s an i n c r e a s i n g l y i m p o r t a n t r o l e i n s h a p i n g and s o r t i n g sand g r a i n s . These sands are w e l l s o r t e d and f i n e - t o medium-grained, as are the M o r r i s e y s a n d s t o n e s . The winnowing a c t i o n o f the waves and wind have c o n c e n t r a t e d the more r e s i s t a n t q u a r t z and c h e r t g r a i n s and c a r r i e d away the l e s s r e s i s t a n t f e l d s p a r s , micas, c a r b o n a t e s and a r g i l l a c e o u s g r a i n s . The N a y a r i t beach sands have v a r i a b l e s h e l l c o n t e n t and d e b r i s l a y e r s of s h e l l s , wood, peat and pumice. A l t h o u g h no s h e l l d e b r i s has been found i n the Moose Mountain s a n d s t o n e s , the l e n s e s o f c o a l y and carbonaceous s h a l e a r e analogous t o the d e b r i s l a y e r s t h a t become c o n c e n t r a t e d i n p r o t e c t e d swales between the r i d g e s . A r g i l l a c e o u s r i p - u p c l a s t s found i n t h e s e sandstones may r e p r e s e n t d e p o s i t s c a r r i e d i n t o swales o r r u n n e l s by washover fans a t h i g h water or d u r i n g storm s u r g e s . G i b s o n and Hughes (1981) f a v o r a storm surge mechanism f o r the emplace-ment of the ammonite T i t a n i t e s o c c i d e n t a l i s found a t the t o p o f the Moose Mountain Member, i n t o the backshore environment. T h i s i s analogous t o the mechanism t h a t i s r e s p o n s i b l e f o r emplacement o f abundant s h e l l s on A u s t r a l i a n and F i j i a n c o a s t l i n e s ( G i b s o n , 1977). S a n d - f i l l e d burrows a r e common i n the Moose Mountain sandstones and may r e p r e s e n t f e e d i n g o r escape burrows o f f r e s h w a t e r o s t r a c o d s (Walker, 1980) or m o l l u s k s , such as are found on the Mexican c o a s t (Curray e t a l . , 1969). H o r i z o n t a l l a m i n a t i o n s a re common i n t h i s sandstone and may r e p r e s e n t p e r i o d s o f beach l e v e l l i n g d u r i n g s e a s o n a l storms. S h a l l o w a n g l e p l a n a r t a b u l a r and t a n g e n t i a l p l a n a r c r o s s b e d d i n g a re c o n s i s t e n t w i t h bedding t y p e s found i n beach r i d g e s and may r e p r e s e n t i n c l i n e d s u r f a c e s o f beaches o r b a r s (Reineck and S i n g h , 1980, p. 382-386). T h i s type o f bedding can d i p towards o r away from the sea. Reineck and Singh (1980, p. 350-352) found t h a t beach r i d g e l a m i n a t i o n s and bed d i n g i n the G u l f of Gaeta, I t a l y , d i p p e d from 5 t o 30 degrees w i t h the s t e e p e r a n g l e s d i p p i n g towards the l a n d . T h i s c o a s t l i n e i s not a f f e c t e d by t i d e s , but r a t h e r l o n g s h o r e c u r r e n t s and storms shape the beach d e p o s i t s . High a n g l e crossbedded sands on the N a y a r i t c o a s t a re formed as lo n g s h o r e b a r s m i g r a t e towards l a n d (Curray e t a l . , 1969). Trough c r o s s b e d d i n g and s t e e p l y a n g l e d c r o s s l a m i n a t i o n s r e s u l t from sand a v a l a n c h e s on a e o l i a n dune s l i p f a c e s d u r i n g dune 49 m i g r a t i o n (Reineck and S i n g h , 1980, p. 350-352). In r e g i o n a l s t u d i e s , G i b s o n and Hughes (1981), have not enc o u n t e r e d marine or b r a c k i s h water d e p o s i t s above the M o r r i s e y F o r m a t i o n . T h i s l e a d t o the s u g g e s t i o n t h a t the beach-ridge-dune complexes were not s e p a r a t e d from the sea by t i d a l l a g o o n s , as i s the case w i t h b a r r i e r b a r s , but r a t h e r were d i r e c t l y connected t o the c o a s t l i n e . In t h i s s t u d y the s t r a t a o f U n i t I are i n t e r p r e t e d t o have formed d i r e c t l y b e h i n d the c o a s t a l beaches and dunes and prograded over t h e s e d e p o s i t s w i t h t i m e . The p r o g r a d a t i o n of the beach complex was p r o b a b l y a r e s u l t o f a d d i t i o n o f sediment from nearby s m a l l d e l t a d i s t r i b u t a r i e s . T h i s sediment would move a l o n g the c o a s t w i t h the a i d o f l o n g s h o r e c u r r e n t s . W ith a c o n t i n u o u s b u i l d i n g out of the c o a s t l i n e , c o a s t a l peat swamps were e s t a b l i s h e d d i r e c t l y b e h i n d the a e o l i a n dunes. T h i s i s analogous t o p e a t s p r e s e n t l y f o r m i n g i n the Dismal Swamp which o c c u r s on the b o r d e r between V i r g i n i a and N o r t h C a r o l i n a . Here, p e a t s a r e p r o t e c t e d from marine i n c u r s i o n s by sand b a r s , s p i t s and i s l a n d c h a i n s . Sim-i l a r i l y , i n Borneo r a i s e d mangrove bogs are p r e s e n t l y f o r m i n g between a n c i e n t beach b e l t s (Anderson, 1964). In some p a r t s o f the st u d y a r e a a s i l t y sandstone o v e r l i e s the a e o l i a n d e p o s i t s and may r e p r e s e n t sediment i n f l u x from a d j a c e n t f l u v i a l systems. A r i s i n g water t a b l e and s l o w l y s u b s i d i n g c o a s t a l p l a i n would a l l o w the f o r m a t i o n of the peat swamp t h a t produced C o a l Seam 1. From f o s s i l e v i d e n c e the peats formed from herbaceous m a t e r i a l s such as sedges, r u s h e s , f e r n s and water l i l i e s (Appendix I ) . B r i g h t bands i n the c o a l i n d i c a t e 50 t h a t a few t r e e s or d r i f t w o o d h o r i z o n s o c c u r r e d i n the reed-dominated peat environment ( T e i c h m u l l e r and T e i c h m u l l e r , 1982). The l a c k o f mudstone s p l i t s i n d i c a t e s a c o n t i n u o u s p e a t - f o r m i n g e nvironment, u n i n t e r r u p t e d by d e t r i t a l i n f l u x e s . The 4 metre maximum c o a l t h i c k n e s s s u g g e s t s a peat f o r m a t i o n p e r i o d of a t l e a s t 24,000 y e a r s ( F i g u r e 20a). The peat f o r m i n g p e r i o d was t e r m i n a t e d by a f l o o d i n g e p i s o d e from a nearby d i s t r i b u t a r y c h a n n e l which d e p o s i t e d f i n e -g r a i n e d s i l t and mud upon the peat ( F i g u r e 20b). The medium- t o d a r k - g r e y (N5-N3), c o l o r and f i n e g r a i n s i z e o f the sediments suggests a subaqueous d e p o s i t i o n i n a backswamp or f l o o d p l a i n a r e a . R i p p l e l a m i n a t i o n s a re i n d i c a t i v e of d e p o s i t i o n by lower f l o w regime c u r r e n t s . Large f l o o d b a s i n s a r e common on c o a s t a l p l a i n s and h o r i z o n t a l l y l a m i n a t e d muds and s i l t s a r e the commonest i n d i c a t i o n s of f i n e - g r a i n e d sediment s e t t l i n g from overbank f l o w s (Reineck and S i n g h , 1980, p.295-298). P l a n t r o o t l e t s a t the top o f the u n i t i n d i c a t e t h a t the peat swamp t h a t produced Seam 2 used the f l o o d b a s i n muds as a s o i l base. C o a l Seam 2 was d e p o s i t e d i n a swamp environment t h a t was c o n t i n u o u s l y i n t e r r u p t e d by the d e p o s i t i o n o f f i n e - g r a i n e d m a t e r i a l as e v i d e n t by a prominent s h a l e y c o a l s p l i t t h a t i n d i c a t e s a p r o l o n g e d f l o o d . P l a n a r l a m i n a t i o n s s uggest f i n e - g r a i n e d p a r t i c l e s e t t l i n g from f l o o d w a t e r s . The geometry of the s h a l e p a r t i n g s u g g e s t s t h a t the peat swamp was f l o o d e d from two s o u r c e s : one i n the n o r t h w e s t and one i n the s o u t h e a s t ( F i g u r e 2 0 c ) . The c e n t r a l a r e a was not a f f e c t e d by f l o o d w a t e r s , perhaps because i t was then t o p o g r a p h i c a l l y h i g h e r than the 5 1 Figure 20 S u c c e s s i v e depos i t iona l environments of Unit I sed iments 52 s u r r o u n d i n g p e a t . The c e s s a t i o n o f peat growth was a r e s u l t o f i n c r e a s e d s u b s i d e n c e which e n a b l e d the r i v e r r e s p o n s i b l e f o r the sands of the lower member of the "A" Sandstone Channel t o d e v e l o p on the peat swamp ( F i g u r e 20d). E r o s i v e c h a n n e l s c o u r i n g d e s t r o y e d the peat i n some areas as b a s a l l a g d e p o s i t s were l a i d down. P l a n t p a r t s were i n c o r p o r a t e d i n t o t h e s e d e p o s i t s and produced c o a l spar t h a t measure up t o a metre i n l e n g t h . Downstream m i g r a t i o n o f sandy sediment produced s m a l l - t o l a r g e - s c a l e (mm-cm), p l a n a r c r o s s b e d s t h a t d e c r e a s e i n s i z e upward c o r r e s p o n d i n g t o a l o w e r i n g o f f l o w i n t e n s i t y . C l i m b i n g r i p p l e s i n d i c a t e a lower f l o w regime and h i g h sediment s u p p l y d u r i n g d e p o s i t i o n . C o n v o l u t e bedding and slump s t r u c t u r e s found i n the f i n e sandstones and s i l t s t o n e s s u ggest an i n s t a b i l i t y o f sands and s i l t s a l o n g the c h a n n e l margin p r i o r t o l i t h i f i c a t i o n . H o r i z o n t a l b edding above the r i p p l e c r o s s - l a m i n a t e d zone was p r o b a b l y formed from s i l t and mud d r o p p i n g out o f s u s p e n s i o n . The "A" Lower Channel seems t o have " s i l t e d up" as a r e s u l t of a v u l s i o n . The abandonment of the "A" Lower Sandstone c h a n n e l p r o v i d e d a r i c h s o i l h o r i z o n f o r the development of a peat f o r m i n g environment t o the n o r t h and a backswamp t o the s o u t h ( F i g u r e 20e). T h i s swamp produced the s h a l e y 3 Seam which i n t e r f i n g e r s w i t h o r g a n i c - r i c h sandstones t o the s o u t h . The common o c c u r r e n c e o f p l a n a r l a m i n a t i o n s suggest suspended sediment d e p o s i t i o n i n a l o w - l y i n g wet b a s i n w i t h the c o a r s e r sediment r e p r e s e n t i n g d i s t a l p o r t i o n s of c r e v a s s e s p l a y a p r o n s . d. e. f. Figure 20 S u c c e s s i v e depos i t iona l env i ronments of Unit I s e d i m e n t s 54 Coa l Seam 3 i s e r o s i o n a l l y o v e r l a i n by the Upper "A" Sandstone ( F i g u r e 2 0 f ) . The cha n n e l r e s p o n s i b l e f o r the Upper "A" Sandstone de v e l o p e d on 3 Seam w i t h i t s a s s o c i a t e d c r e v a s s e s p l a y and f l o o d p l a i n d e p o s i t s . The c h a r a c t e r of the s t r u c t u r a l f e a t u r e s a r e the same as tho s e found i n the Lower "A" Channel. These c h a n n e l s a re i n t e r p r e t e d as d i s t r i b u t a r y c h a n n e l s on a lower c o a s t a l p l a i n . A t o t a l - s a n d s t o n e i s o l i t h map f o r the i n t e r v a l between Seams 2 and 4 was c o n s t r u c t e d t o det e r m i n e the e f f e c t , i f any, of the "A" Channels on 2 Seam ( F i g u r e 1 8 ) . T h i s i s o l i t h i s a t o t a l t h i c k n e s s map t h a t r e p r e s e n t s the combined a r e a l coverage of the c h a n n e l s shown i n f i g u r e s 20d and 20f. When the 2 Seam i s o p a c h map i s superimposed on t h i s map, a d e f i n i t e r e l a t i o n s h i p emerges. The sandstones a re t h i c k e s t (25 m e t r e s ) , i n the c e n t r a l t o s o u t h e a s t e r n a r e a s where 2 Seam i s t h i n n e r . C o n v e r s e l y , a t the c h a n n e l edges (0-4 metres) o r where the c h a n n e l i s a b s e n t , the c o a l s a r e the t h i c k e s t . T h i s i n d i c a t e s the e r o s i v e n a t u r e o f the sandstone c h a n n e l . I t a l s o i n d i c a t e s t h a t 2 Seam r e t a i n e d i t s f u l l t h i c k n e s s i n f l o o d p l a i n a r e a s where d e p o s i t i n g c u r r e n t s were n o n - e r o s i v e and became t h i n n e r as a r e s u l t of c h a n n e l l i n g d u r i n g d e p o s i t i o n o f "A" Chann e l . An i s o - a s h map of 2 Seam was p r e p a r e d from w a s h a b i l i t y d a t a t o d e t e r m i n e the e f f e c t , i f any, t h a t p r o x i m i t y t o c h a n n e l s had on the c o a l q u a l i t y . The ash c o n t e n t v a l u e s a re p l o t t e d on f i g u r e 18. The h i g h e s t ash c o n t e n t s o c c u r a d j a c e n t t o deepest c h a n n e l a r e a s , w h i l e the lower v a l u e s o c c u r a t the t h i n n e r c h a n n e l margins i n d i c a t i n g t h a t c l o s e p r o x i m i t y t o c h a n n e l s 55 i n c r e a s e s c o a l ash c o n t e n t s . The f i n a l sequence of U n i t I i s composed of i n t e r b e d d e d sandstone and s i l t s t o n e d e p o s i t e d as a r e s u l t o f abandonment of Upper "A" Channel ( F i g u r e 20g). C r e v a s s i n g of the c h a n n e l may have p l a y e d a major r o l e i n s h a p i n g the d r a i n a g e p a t t e r n . C r e v a s s e c h a n n e l s are r e c o g n i z e d as s a n d s t o n e - s i l t s t o n e s e t s o f 2 t o 3 metres i n t h i c k n e s s t h a t are p e t r o g r a p h i c a l l y s i m i l a r t o the "A" Channel s a n d s t o n e s . T h e i r main c h a r a c t e r i s t i c s i n c l u d e a b a s a l l a g d e p o s i t and s m a l l - t o medium-scale c r o s s b e d d i n g t h a t r e p r e s e n t s h i g h i n t e n s i t y f l o w i n a lower f l o w regime. Slumping of u n s t a b l e c h a n n e l margins i s i n d i c a t e d by s o f t sediment d e f o r m a t i o n i n the form of c o n v o l u t e l a m i n a t i o n s and slump s t r u c t u r e s . A f i n i n g - u p w a r d s t o s i l t s t o n e s marks waning of the f l o w . The s i l t s t o n e s show s m a l l - s c a l e p l a n a r and r i p p l e l a m i n a t i o n s c o r r e s p o n d i n g t o a lower c u r r e n t s t r e n g t h . O c c a s i o n a l slump s t r u c t u r e s and r i p - u p c l a s t s i n d i c a t e e r o s i v e f l o o d w a t e r s . The s i l t s t o n e s may a l s o r e p r e s e n t d i s t a l p o r t i o n s of s p l a y s which f i n e away from the main f l u v i a l c h a n n e l . The r e - e s t a b l i s h -ment of v e g e t a t i o n i s i n d i c a t e d by p l a n t s r o o t i n the uppermost bed of U n i t I . The s i l t s t o n e s f i n e - u p w a r d i n t o a carbonaceous muddy s i l t s t o n e of f l o o d p l a i n o r i g i n . The predominant p l a n a r l a m i n a t i o n s r e p r e s e n t d e p o s i t i o n of f i n e p a r t i c l e s from s u s p e n s i o n , p r o b a b l y as a r e s u l t o f p e r i o d i c f l o o d i n g . Mudstone i n t e r v a l s are composed of i l l i t e and k a o l i n i t e . The i l l i t e i s degraded i n d i c a t i n g t h a t the i n t e r - l a y e r p o t a s s i u m has been l e a c h e d from i t s p o s i t i o n by f r e s h water or by the c r o p p i n g 56 Figure 20 S u c c e s s i v e depos i t iona l envi ronments of Unit I s e d i m e n t s 57 a c t i o n o f p l a n t s ( B u s t i n and B a y l i s s , 1979). 2.4.3. U n i t I I C h a r a c t e r i s t i c s The m i d d l e l i t h o s t r a t i g r a p h i c package comprises C o a l Seams 4 Lower and Upper, 5 Lower and Upper, 7, 8 and Sandstones "B", "C" and "D" and t h e i r a s s o c i a t e d f i n e r - g r a i n e d sediments ( F i g u r e 8 ) . Those sequences not composed o f sandstone b o d i e s a re i n t e r b e d d e d s a n d s tone, s i l t s t o n e and mudstone. U n i t I I i s d i f f e r e n t i a t e d on the b a s i s of sandstone abundance and geometry when compared w i t h sediments o f U n i t I . In U n i t I the main sandstone body t r e n d s n o r t h w e s t - s o u t h e a s t , whereas i n U n i t I I the t h r e e major sandstone b o d i e s t r e n d n o r t h e a s t t o southwest. C o a l Seam Four Lower Four Seam i s d i v i d e d i n t o Lower and Upper seams over most of the stu d y a r e a . Four Lower re a c h e s i t s maximum t h i c k n e s s of 15 metres i n the no r t h w e s t s e c t o r and t h i n s t o 2 metres i n the n o r t h e a s t , 3 metres i n the so u t h and 5 metres i n the s o u t h e a s t . The c o a l i s b l o c k y t o sheared i n o u t c r o p w i t h mudstone and s i d e r i t i c p a r t i n g s up t o 2 metres t h i c k . The mudstone i s da r k -g r e y t o b l a c k (N3-N1), w i t h abundant c o a l y l a m i n a t i o n s . The s i d e r i t i c p a r t i n g s , i n c o n t r a s t , a re b l u i s h - b l a c k (5 PB 3/2), and s p h e r u l i t i c . The s p h e r u l e s a re 1 t o 2 m i l l i m e t r e s i n di a m e t e r and h a r d and dense. The s i d e r i t i c p a r t i n g s can be t r a c e d f o r 100 metres i n o u t c r o p i n the n o r t h w e s t e r n p a r t o f the st u d y a r e a . The p a r t i n g s a re d i s t i n c t because of a d i f f e r e n c e i n l u s t r e between the v i t r e o u s c o a l bands and the d u l l s i d e r i t e . 58 I r o n s t a i n i n g o c c u r s on some weathered s u r f a c e s . The g e o p h y s i c a l l o g r esponse i l l u s t r a t e s c l e a r l y the m u d s t o n e ^ s i d e r i t i c p a r t i n g w h i c h i s i d e n t i f i e d by i t s medium t o h i g h gamma r a y v a l u e as compared t o the c o a l ' s lower v a l u e ( F i g u r e 1 9 ) . Co a l Seams 4L and 4U are s e p a r a t e d by a s i 1tstone-mudstone i n t e r v a l t h a t has a maximum t h i c k n e s s o f 37 metres i n the n o r t h and d i m i n i s h e s t o 2 metres i n the southwest. T h i s sequence t h i n s and s h a l e s out t o the e a s t and s o u t h . The s i l t s t o n e appears d a r k - g r e y (N3), i n o u t c r o p and c o n t a i n s c o a l y b i t s and f o s s i l p l a n t s . P l a n a r l a m i n a t i o n s a re the predominant s e d i m e n t a r y s t u c t u r e s . The c o n t a c t w i t h the o v e r l y i n g 4U seam i s g r a d a t i o n a l . The g r a d a t i o n a l c o n t a c t s between t h e s e i n t e r b e d d e d sediments show up as i n d i s t i n c t c o n t a c t s on the g e o p h y s i c a l t r a c e . R e s u l t s o f a p e t r o g r a p h i c e x a m i n a t i o n of a carbonaceous s i l t s t o n e i n the f o o t w a l l o f 4U seam i n the n o r t h w e s t e r n s e c t o r a r e p r e s e n t e d i n Appendix I I . The q u a r t z and c h e r t g r a i n s of the framework are surrounded by a m a t r i x o f carbonaceous and o r g a n i c fragments t h a t g i v e the t h i n s e c t i o n an o v e r a l l brown appear-ance. A sample was a l s o c o l l e c t e d f o r e x a m i n a t i o n by X-ray d i f f r a c t i o n i n o r d e r t o det e r m i n e the c l a y m i n e r a l s p r e s e n t . The main c l a y m i n e r a l s a re i l l i t e and k a o l i n i t e (Appendix I I I ) . The i l l i t e i s degraded i n d i c a t i n g t h a t the i n t e r - l a y e r p o t a s s i u m has been removed by p l a n t c r o p p i n g or f r e s h water l e a c h i n g ( B u s t i n and B a y l i s s , 1979). C o a l Seam Four Upper C o a l Seam 4U a t t a i n s i t s maximum t h i c k n e s s of 11 metres i n 59 t h e southwest s e c t o r o f the stu d y a r e a . The seam i s b l o c k y t o sheared and v i t r a i n i s the main l i t h o t y p e . I t t h i n s t o 4 metres i n the n o r t h e a s t and s o u t h e a s t and d e v e l o p s a c o n s p i c u o u s s i l t s t o n e s p l i t i n the n o r t h . Where p r e s e n t , the p a r t i n g i s composed o f f i n e - t o medium-grained, d a r k - g r e y (N3), c a r b o n a -ceous s i l t s t o n e . The o n l y s e d i m e n t a r y s t r u c t u r e s found a re p l a n a r l a m i n a t i o n s . The g e o p h y s i c a l l o g s i g n a t u r e f o r t h i s seam i s v e r y c h a r a c t e r i s t i c . I t u s u a l l y d i s p l a y s a g r a d a t i o n a l lower c o n t a c t , a v e r y low b l o c k y gamma r a y v a l u e and an ab r u p t upper c o n t a c t . The s i l t s t o n e s p l i t shows up as a v e r y h i g h gamma r a y v a l u e . Four Upper t o F i v e Lower I n t e r b u r d e n The t o t a l t h i c k n e s s of t h i s i n t e r v a l i s g r e a t e s t i n the southwest a t 76 metres. G e n e r a l l y those a r e a s w i t h a g r e a t e r c o n c e n t r a t i o n o f sandstone show the t h i c k e s t sequences. The "B" Sandstone i s o l i t h map g i v e s the t r e n d o f the t o t a l sandstone t h i c k n e s s between 4U and 5L seams ( F i g u r e 2 1 ) . The c r o s s s e c t i o n s g i v e a more r e a l i s t i c p i c t u r e o f the geometry of sandstone b o d i e s . As shown i n F i g u r e s 22 and 23 the c o n t a c t of the 4U c o a l seam and the o v e r l y i n g sandy s i l t s t o n e i s g e n e r a l l y g r a d a t i o n a l , but o c c a s i o n a l l y a b r u p t . In o u t c r o p t h i s s i l t s t o n e i s medium- t o c o a r s e - g r a i n e d and weathers a l i g h t - b r o w n t o r e d d i s h - o r a n g e (10 YR 8/2-10 YR 6/6). I t can a l s o appear l i g h t -t o medium-grey (N7-N5). The se d i m e n t a r y s t r u c t u r e s o b s e r v e d i n o u t c r o p and c o r e i n c l u d e p l a n a r and r i p p l e l a m i n a t i o n s and p l a n a r c r o s s b e d d i n g . S o f t - s e d i m e n t s l u m p i n g , c o n v o l u t e l a m i n a t i o n s and burrows a l s o o c c u r . C a r b o n i z e d p l a n t i m p r e s s i o n s 60 N N E T C H A N N E L S A N D S T O N E 1 | 0 - 1 0 m e t r e s [r||i:j| 1 0 - 2 0 m e t r e s lllll] > 20 m e t r e s 2 2 • R a w c o a l a s h c o n t e n t ( w e i g h t %) 5 0 0 ~4 C o a l s e a m 5 L o w e r t h i c k n e s s ( m e t r e s ) D i a m o n d a n d r o t a r y dr i l l h o l e s * H o l e s u s e d for c r o s s s e c t i o n s o C o r e d h o l e s 500 1000 m e t r e s Figure 21 " B " c h a n n e l isolith map and C o a l S e a m 5 L o w e r i s o p a c h map 0. E Ul O L I T H O L O G Y & GRAIN SIZE C L S VF F M i i i i i_ S T R U C T U R E R E M A R K S 1 9 0 H 1 8 0 1 7 0 -160 -150 140 130 -1 2 0 -1 1 0 -100 -9 0 -8 0 7 0 6 0 5 0 4 0 3 0 = V = 0 0 = 2/ = rm = 0 C h a n n e l f l o o r M i n o r c o a l s e a m s C h a n n e l f l o o r S e a m 4 F igure 22 C L O D E PIT W E S T T R A V E R S E , Sediments of Unit II 62 Q. E o 1 9 0 -1 8 0 -1 7 0 -160 i 1 5 0 4 140 L I T H O L O G Y & GRAIN SIZE C L S V F F M i i i ' ' 130 4: 1 2 0 -f 1 1 0 -1 0 0 -9 0 8 0 -t 70 -\ 6 0 H 10 S T R U C T U R E ix o = y\ CD = 0 7777 7777 JUT mr mr R E M A R K S C o l o u r b a n d e d s i l t s t o n e s B a n d e d s i l t s t o n e s a n d s h a l e s S h e a r e d c o a l s e a m 5 W e a t h e r e d - o u t s h a l e l e n s e s 2 m w i d e . 112 m h i g h C h a n n e l f l o o r S e a m 4 Figure 2 3 E A G L E S O U T H W E S T T R A V E R S E 1 - 3 , S e d i m e n t s of Unit II 63 up t o 10 c e n t i m e t r e s i n l e n g t h a re p r e s e n t on bed d i n g p l a n e s . P e t r o g r a p h i c a n a l y s i s o f the s i l t s t o n e i s shown i n Appendix I I (sample 9 ) . The p r i m a r y c o n s t i t u e n t s a re q u a r t z , c a r b o n a t e and opaque m i n e r a l s i n an o r g a n i c and c a r b o n a t e m a t r i x . The c o n t a c t o f the sandy s i l t s t o n e and the base o f the "B" Sandstone i s e r o s i o n a l and uneven. Channel l a g d e p o s i t s i n the form o f c a r b o n i z e d t r e e f r a g m e n t s , up t o 3 metres i n l e n g t h , and a r g i l l a c e o u s r i p ^ u p c l a s t s a r e common a l o n g t h i s boundary. The "B" Sandstone i s a medium- t o c o a r s e - g r a i n e d l i t h a r e n i t e . I t i s s a l t and pepper c o l o r e d (N7), and v e r y r e s i s t a n t . P r i m a r y s e d i m e n t a r y s t r u c t u r e s i n c l u d e p l a n a r and t a n g e n t i a l c r o s s b e d d i n g , p l a n a r and r i p p l e l a m i n a t i o n s and a r g i l l a c e o u s c l a s t s . D e f o r m a t i o n o f the sediments has been caused by b i o t u r b a t i o n and s l u m p i n g . F o s s i l i z e d p l a n t m a t e r i a l i s common on bed d i n g p l a n e s and l o a d and f l u t e c a s t s a r e p r e s e n t i n some a r e a s . C a r b o n i z e d r o o t l e t s can o f t e n be observed c u t t i n g t h r o u g h bedding s u r f a c e s . C o a l Seams F i v e , F i v e Lower and F i v e Upper "Number 5 Seam" can be d i v i d e d i n t o t h r e e seams a t v a r i o u s l o c a t i o n s ' i n t he s t u d y a r e a . The t h i c k n e s s e s and g e o m e t r i e s a re i l l u s t r a t e d i n f i g u r e s 9-13 (Map P o c k e t ) . F i v e Lower Seam (5L) i s r e l a t i v e l y c o n s i s t e n t a c r o s s the n o r t h e r n a r e a c o m p r i s i n g 2.5 metres of c o a l w i t h a 1 t o 2 metre s h a l e p a r t i n g . However, i t i s d i s t u r b e d by a d j a c e n t c h a n n e l l i n g i n t he w e s t - c e n t r a l and s o u t h - c e n t r a l a r e a s . Channels have the e f f e c t of e i t h e r e r o d i n g the c o a l seam or c a u s i n g an i n c r e a s e i n number of p a r t i n g s because o f d e t r i t u s i n p u t by c r e v a s s e s p l a y s . 64 In o u t c r o p 5L i s a s h a l e y c o a l or carbonaceous mudstone w i t h a sheared t e x t u r e . V i t r a i n and d u r a i n a re the predominant l i t h o t y p e s . F o s s i l p l a n t m a t e r i a l i s common a l o n g the bedding p l a n e s . Where t h i s seam i s p r e s e n t , the g e o p h y s i c a l l o g t r a c e i s b l o c k y t o i n d i s t i n c t , depending on the amount of s h a l e y m a t e r i a l p r e s e n t i n the seam. The s h a l e p a r t i n g s show d i s t i n c t i v e h i g h gamma r a y v a l u e s and s h a l e y c o a l shows low t o medium gamma v a l u e s . C o a l Seam 5 Occurs o n l y i n the w e s t - c e n t r a l and sou t h w e s t e r n a r e a s and has a t h i c k n e s s o f 1 metre. I t i s s e p a r a t e d from 5L and 5U by mudstone and s i l t s t o n e beds t h a t e x h i b i t p l a n a r l a m i n a t i o n s , c l i m b i n g r i p p l e s and b u r r o w i n g . Seam 5 i s b l o c k y t o sheared i n o u t c r o p . The g e o p h y s i c a l t r a c e shows moderate gamma v a l u e s t h a t i n d i c a t e a c o a l y s h a l e . I t has i n d i s t i n c t c o n t a c t s w i t h the r o o f and f l o o r r o c k s . The t h i c k n e s s o f C o a l Seam 5U i s c o n s i s t e n t i n the w e s t e r n a r e a a t 3 metres. In the e a s t e r n and c e n t r a l areas i t d i v i d e s i n t o two 1 metre seams s e p a r a t e d by a 3 metre s h a l e p a r t i n g . In the n o r t h - c e n t r a l r e g i o n , ( F i g u r e 9, Map P o c k e t ) , 5U i s absent as a r e s u l t of c h a n n e l l i n g . In o u t c r o p the c o a l i s a r g i l l a c e o u s and s h e a r e d . The g e o p h y s i c a l s i g n a t u r e , shown i n f i g u r e 24, i s c h a r a c t e r i z e d by low t o moderate gamma v a l u e s w i t h i n d i s t i n c t c o n t a c t s . F i v e To Seven Seam I n t e r b u r d e n The geometry and c o m p o s i t i o n of t h i s sequence a r e i l l u s t r a t e d i n f i g u r e s 9-13 (Map P o c k e t ) . T h i s sequence i s composed o f a s t a c k e d s e r i e s of sandstone b o d i e s t r e n d i n g 65 F i g u r e 2 4 D O H 1 7 5 2 S E D I M E N T S O F U N I T II 66 r o u g h l y n o r t h e a s t t o southwest ( F i g u r e 25). These sandstones have c o l l e c t i v e l y been c a l l e d "C" Sandstone and were i s o l i t h e d as the t o t a l - s a n d s t o n e t h i c k n e s s between Seams 5 and 7. The i s o l i t h g i v e s an i n d i c a t i o n of o v e r a l l t r e n d . As shown i n f i g u r e 25, the g r e a t e s t t h i c k n e s s o c c u r s i n the n o r t h - c e n t r a l a r e a a t 183 metres. Minimum t h i c k n e s s e s of 19 and 24 metres o c c u r i n the n o r t h w e s t and s o u t h e a s t a r e a s , r e s p e c t i v e l y . Even d i s r e g a r d i n g the f i v e t imes v e r t i c a l e x a g e r a t i o n o f the c r o s s s e c t i o n s ( F i g u r e s 9-13) the a e r e a l d i f f e r e n c e s i n t h i c k n e s s are w e l l i l l u s t r a t e d . A n a t u r a l s c a l e c r o s s s e c t i o n ( F i g u r e 2 6 ) , o f the 5 t o 7 seam i n t e r v a l d i s p l a y s a d i p of 6 t o 8 degrees between the west and c e n t r a l a r e a s measured on t o p o f 5 Seam. T h i s 6 degree s l o p e i s c o n s i d e r e d a r e s u l t o f d i f f e r e n t i a l compaction of the u n d e r l y i n g u n i t s . The s i l t s t o n e and mudstone i n t e r v a l s would compact more than the sandstone c h a n n e l s . In o u t c r o p , r e s i s t a n t sandstones range from 4 t o 17 metres i n t h i c k n e s s . The sandstones are l i t h a r e n i t e s t h a t are f i n e - t o medium-grained and b r o w n i s h - g r e y (5 YR 4/1), ( F i g u r e 24). B a s a l c o n t a c t s a r e e r o s i o n a l and l a g d e p o s i t s of a r g i l l a c e o u s r i p - u p c l a s t s and c o a l fragments are common. P l a n t f o s s i l s o c c u r on b e dding p l a n e s and bedding has been d i s t u r b e d by b i o t u r b a t i o n . The most common p r i m a r y s t u c t u r e s observed were p l a n a r c r o s s b e d s , p l a n a r and r i p p l e c r o s s - l a m i n a t i o n s and c l i m b i n g r i p p l e s . C o n v o l u t e bedding and s l u m p i n g l o c a l l y o c c u r s . F i n i n g - u p w a r d sequences of sandstones t o s i l t s t o n e s and c o a l y mudstones are common and e a s i l y r e c o g n i z e d on g e o p h y s i c a l N E T C H A N N E L S A N D S T O N E * D i a m o n d and r o t a r y dr i l l h o l e s * H o l e s u s e d for c r o s s s e c t i o n s o C o r e d h o l e s L F i g u r e 25 " C " c h a n n e l isolith i s o p a c h m a p . map and C o a l S e a m 5 U p p e r WEST 1753B 1659T EAST 350 1660T Siltstone and Mudstone M>M Sandstone H i Coal Seam 70 0 70 140 metres S c a l e : Ve r t i ca l = Horizontal Figure 26 Natura l s c a l e d iagram of a protion of 5 to 9 seam interval from c r o s s - s e c t i o n 1 69 l o g s . The sandstones show a low t o moderate gamma r a y response w i t h sharp b a s a l c o n t a c t s . The upper c o n t a c t s a re g r a d a t i o n a l t o i n t e r b e d d e d s i l t s t o n e and mudstone. T h i n c o a l beds commonly cap the s e f i n i n g upward sequences and are i n sharp c o n t a c t w i t h the o v e r l y i n g s andstone. In a r e a s removed from the main channel system, such as i n the n o r t h w e s t and s o u t h e a s t , f i n i n g upward sandstone and s i l t s t o n e sequences of a more l i m i t e d t h i c k n e s s (1 t o 3 m e t r e s ) , o c c u r . R i p p l e l a m i n a t i o n s and c l i m b i n g r i p p l e s a r e the predominant s e d i m e n t a r y s t r u c t u r e s . Other a r e a s a r e d e v o i d o f any major sandstones and the 5-7 Seam i n t e r v a l i s composed o f i n t e r b e d d e d s i l t s t o n e and mudstone. In o u t c r o p the s i l t s t o n e s a r e d a r k - g r e y t o b r o w n i s h - g r e y (N3-5 YR 4/1), and appear c o l o r - b a n d e d where i r o n - r i c h c o n c r e t i o n s a re c o n c e n t r a t e d . The i r o n - r i c h bands a re more r e s i s t a n t than t h e carbonaceous s h a l e s and are b l o c k y i n t e x t u r e . R i p p l e and p l a n a r l a m i n a t i o n s and c o n c r e t i o n s are the commonest se d i m e n t a r y s t r u c t u r e s . P l a n a r c r o s s b e d s , slump s t u c t u r e s and b u r r o w i n g a re o c c a s i o n a l l y p r e s e n t . The g e o p h y s i c a l l o g s i g n a t u r e i s i n d i s t i n c t w i t h g r a d a t i o n a l c o n t a c t s between moderate gamma r a y v a l u e s i l t s t o n e s and h i g h e r gamma r a y v a l u e mudstones. The c o n t a c t s w i t h the u n d e r l y i n g 5 Seam and the o v e r l y i n g 7 Seam are g r a d a t i o n a l and i n d i s t i n c t ( F i g u r e 2 4). Co a l Seam Seven The geometry and v e r t i c a l c o n f i g u r a t i o n o f 7 Seam are i l l u s t r a t e d i n f i g u r e s 9-13 (Map P o c k e t ) . Seam 7 i s complex seam 70 w i t h s u b s t a n t i a l a e r e a l d i f f e r e n c e s i n t h i c k n e s s and number of p a r t i n g s p r e s e n t . F i g u r e s 9, 10 and 11 show the seam as b e i n g f a i r l y c o n s i s t e n t i n the e a s t e r n and c e n t r a l a r e a s i n r e g a r d s t o the number o f p a r t i n g s . The seam v a r i e s i n t h i c k n e s s from 3 metres i n the n o r t h e a s t and s o u t h e a s t t o 13 metres i n the c e n t r a l a r e a . The w e s t e r n s e c t o r shows a change i n seam c h a r a c t e r w i t h the number of p a r t i n g s i n c r e a s i n g and the o v e r a l l t h i c k n e s s a v e r a g i n g 7 metres. F i g u r e s 12 and 13 i l l u s t r a t e t he e f f e c t a n o r t h e r n c h a n n e l has on the seam. I t d e v e l o p s more p a r t i n g s a d j a c e n t t o the ch a n n e l and appears t o be washed out i n one a r e a . The i s o p a c h o f "D" Sandstone shows the n o r t h e a s t t o southwest t r e n d o f the sandstone ( F i g u r e 27). Seam 7 i s sheared t o b l o c k y w i t h c o a l y s i l t s t o n e p a r t i n g s . In diamond d r i l l c o r e the p a r t i n g s a re d a r k - g r e y (N3), and f i n e - t o medium-grained. P l a n a r and r i p p l e l a m i n a t i o n s are the commonest s e d i m e n t a r y s t r u c t u r e s . F o s s i l i z e d p l a n t p a r t s a re abundant on bedding p l a n e s . A s p h e r u l i t i c p a r t i n g was found i n d r i l l c o r e . The p a r t i n g and a d j a c e n t c o a l s were a n a l y z e d by X-ray d i f f r a c t i o n and S.E.M. t o det e r m i n e c o m p o s i t i o n . Both methods d e t e r m i n e d the p a r t i n g t o be s i d e r i t e . R e s u l t s a re p r e s e n t e d i n Appendix IV. The s i d e r i t e i s e a s i l y d i s t i n g u i s h e d from the c o a l because of i t s s p h e r u l i t i c t e x t u r e and h i g h d e n s i t y . A l t h o u g h the c o l o r s are s i m i l a r , the p a r t i n g has a s u p e r i o r hardness and d u l l e r l u s t r e . The s i d e r i t e p a r t i n g i s r a r e l y d i f f e r e n t i a t e d from the s u r r o u n d i n g c o a l seam on g e o p h y s i c a l t r a c e s . T h i s may be because N E T C H A N N E L S A N D S T O N E l l i l l l 0 - 1 0 m e t r e s 1 0 - 2 0 m e t r e s > 20 m e t r e s 2 6 • R a w c o a l a s h c o n t e n t (we ight %) 10 C o a l s e a m 9 t h i c k n e s s ( m e t r e s ) • D i a m o n d a n d r o t a r y dr i l l h o l e s • H o l e s u s e d for c r o s s s e c t i o n s o C o r e d h o l e s 500 500 1000 m e t r e s F i g u r e 27 " D " c h a n n e l iso l i th map and C o a l S e a m 9 i s o p a c h map 72 the p a r t i n g i s o n l y 10 c e n t i m e t r e s t h i c k . The gamma r a y s i g n a t u r e f o r 7 Seam v a r i e s from a v e r y low b l o c k y response where the seam i s t h i c k and c l e a n t o a low-moderate, i n d i s t i n c t r e sponse where p a r t i n g s i n c r e a s e . The lower and upper c o n t a c t s a r e g r a d a t i o n a l w i t h c o a l y mudstones of the r o o f and f l o o r . Seven To Nine Seam I n t e r b u r d e n T h i s i n t e r v a l i s complex because of the l i m i t e d d i s t r i b u t i o n o f 8 Seam and numerous sandstone b o d i e s . F i g u r e s 9-13 (Map Pocket) i l l u s t r a t e the c o m p l e x i t y . An i s o l i t h of t o t a l - s a n d s t o n e o c c u r r i n g i n t h i s i n t e r v a l , t he "D" Sandstone i s o l i t h , i s shown i n f i g u r e 27. The o v e r a l l t r e n d o f the i n t e r v a l i s n o r t h e a s t t o west-southwest which i s c o n s i s t e n t w i t h the t r e n d s o f Sandstones "B" and "C". The combined t h i c k n e s s o f the sequence i s g r e a t e s t i n the n o r t h and c e n t r a l a r e a s w i t h a maximum t h i c k n e s s o f 70 metres. The i n t e r v a l t h i n s t o 16 metres i n the s o u t h . Sandstone b o d i e s up t o 11 metres i n t h i c k n e s s o c c u r i n a s t a c k e d sequence i n the west ( F i g u r e 28). A s e p a r a t e sandstone body, 7 metres i n t h i c k n e s s , o c c u r s i n the e a s t - c e n t r a l a r e a . In areas where the sandstone sequences do not o c c u r , the i n t e r v a l i s composed o f i n t e r b e d d e d s a n d s tone, s i l t s t o n e and mudstone. C o a l Seam 8 reaches a maximum of 3 metres i n the e a s t - c e n t r a l a r e a and s h a l e s out t o the n o r t h and west ( F i g u r e 2 9 ) . A l t h o u g h t h i n , a t 1 t o 2 metres, i t i s s t i l l r e c o g n i z a b l e i n the southwest. C o a l Seam 8 i s i n d i s t i n c t on the gamma r a y l o g because of i t s s h a l e y n a t u r e . I t shows a moderate v a l u e t h a t can be e a s i l y m i s t a k e n f o r the s i g n a t u r e of a s i l t y s andstone. In Figure 28 DDH 1750 S t a c k e d "D" s a n d s t o n e , S e d i m e n t s of Unit II 74 o u t c r o p , 8 Seam i s s h a l e y and sheared. The sandstone b o d i e s were not observed i n o u t c r o p but are w e l l d e f i n e d i n c o r e and g e o p h y s i c a l l o g s . In co r e t h e s e s i l t y s andstones a r e l i g h t - g r e y (N7), and f i n e - t o medium-grained. The b a s a l c o n t a c t s a r e e r o s i o n a l w i t h u n d e r l y i n g s i l t s t o n e s , which i s r e f l e c t e d i n a c h a r a c t e r i s t i c gamma r a y response shown on f i g u r e 28. The sandstones i n c l u d e a r g i l l a c e o u s r i p - u p c l a s t s and c o a l spar fragments i n b a s a l l a g d e p o s i t s . Sedimentary s t r u c t u r e s i n c l u d e p l a n a r and r i p p l e l a m i n a t i o n s , p l a n a r c r o s s b e d s , c l i m b i n g r i p p l e s and l o a d c a s t s . S o f t - s e d i m e n t slump s t r u c t u r e s and b i o t u r b a t i o n a r e common. A f i n i n g - u p w a r d t r e n d i s i n d i c a t e d as s i l t s t o n e s and o v e r l y i n g mudstones show an i n c r e a s i n g gamma r a y v a l u e ( F i g u r e 2 8 ) . The s i l t s t o n e s i n o u t c r o p weather b l u i s h - b l a c k t o y e l l o w - o r a n g e (5 PB 3/2-10 YR 6/6). They a r e f i s s i l e , r e c e s s i v e and e x h i b i t p l a n a r and r i p p l e l a m i n a t i o n s and c l i m b i n g r i p p l e s . Load c a s t s and r i p - u p c l a s t s are o c c a s i o n a l l y seen. Slump s t r u c t u r e s and b i o t u r b a t i o n are a l s o p r e s e n t . The b a s a l and upper c o n t a c t s of t h i s i n t e r v a l a r e g r a d a t i o n a l and i n d i s t i n c t on g e o p h y s i c a l l o g s as a r e s u l t o f 7 Seam g r a d i n g up i n t o a c o a l y mudstone. At the top o f t h i s i n t e r v a l a c o a l y mudstone changes g r a d u a l l y i n t o 9 Seam. N O R T H S O U T H 4 1 1 1 5 6 9 T 1 6 3 7 1 6 3 9 Figure 29 Natural sca le diagram of a portion of 7 to 9 Seam interval from c r o s s - s e c t i o n 5 76 2.4.4. U n i t I I Sedimentology With the abandonment and i n f i l l i n g of "A" Channel , c o a l swamp "4L" was e s t a b l i s h e d on the f i n e - g r a i n e d f l o o d p l a i n ( F i g u r e 30a). The maximum t h i c k n e s s o f 15 metres suggests a s t a b l e , p e a t - f o r m i n g p e r i o d o f a t l e a s t 90,000 y e a r s . B r e a c h i n g o f a d j a c e n t c h a n n e l s t o the n o r t h w e s t and s o u t h e a s t caused i n -f r e q u e n t f l o o d i n g by s p l a y l o b e s i n t o the backswamp a r e a s . S i d -e r i t i c p a r t i n g s i n the c o a l seam are i n d i c a t i v e o f low s u l p h i d e a c t i v i t y , h i g h c a r b o n a t e a c t i v i t y and h i g h F e 2 + / C a 2 + c o n d i t i o n s d u r i n g d i a g e n e s i s (Spears and Amin, 1981). Peat swamp "4L" was i n u n d a t e d by the f l o o d w a t e r s of the a d j a c e n t c h a n n e l s and a p e r i o d o f f i n e - g r a i n e d s e d i m e n t a t i o n began ( F i g u r e 30b). The maximum t h i c k n e s s o c c u r s i n the n o r t h and s u g g e s t s a b r e a c h i n g o f the n o r t h e r n c h a n n e l as opposed t o the s o u t h e a s t e r n s o u r c e . The i n t e r b e d d e d s i l t s t o n e s and s h a l e s a re c o n s i d e r e d t o be of d i s t a l s p l a y o r i g i n . P l a n a r l a m i n a t i o n s suggest d e p o s i t i o n from a lower f l o w regime. Suspended l o a d s i n waning f l o o d w a t e r s would t r a n s p o r t m a t e r i a l , s i m i l a r i n c o m p o s i t i o n t o r i v e r s e d i m e n t s , i n t o f l o o d p l a i n r e g i o n s . N o n - e r o s i v e c o n t a c t s between the d e p o s i t s s u p p o r t t h i s mode o f d e p o s i t i o n . A c e s s a t i o n i n f l o o d i n g a l l o w e d the e s t a b l i s h m e n t of the "4U" peat swamp ( F i g u r e 3 0 c ) . The maximum t h i c k n e s s o f 11 metres s u g g e s t s a peat d e p o s i t i o n p e r i o d o f a t l e a s t 66,000 y e a r s . A s i l t s t o n e s p l i t i n the n o r t h w e s t s u g g e s t s t h a t the n o r t h e r n r i v e r was s t i l l i n e x i s t a n c e and was p e r i o d i c a l l y breached t o c r e a t e s p l a y d e p o s i t s . The p l a n a r l a m i n a t i o n s suggest t h a t the Figure 3 0 S u c c e s s i v e d e p o s i t i o n a l env i ronments of Unit II s e d i m e n t s 78 c o a l y s i l t s t o n e s were l a i d down i n the d i s t a l s p l a y p o s i t i o n . The "4U" peat swamp d e p o s i t i o n was c o n c l u d e d when c r e v a s s e s p l a y s i l t s t o n e s c o v e r e d the p e a t s . These s i l t s t o n e s a re o f the same m i n e r a l o g i c a l c o m p o s i t i o n as the o v e r l y i n g "B" Sandstone and show c h a r a c t e r i s t i c s of c r e v a s s e c h a n n e l s and p r o x i m a l s p l a y l o b e s . The c r e v a s s e c h a n n e l s e x h i b i t a b r u p t t o e r o s i o n a l b a s a l c o n t a c t s , p l a n a r c r o s s b e d d i n g and s o f t - s e d i m e n t s l u m p i n g a l o n g c h a n n e l margins. P r o x i m a l s p l a y d e p o s i t s e x h i b i t g r a d a t i o n a l b a s a l c o n t a c t s and p l a n a r and r i p p l e l a m i n a t i o n s . The Lower "B" Channel moved i n t o t h i s a r e a and s c o u r e d i n t o the u n d e r l y i n g s p l a y d e p o s i t s ( F i g u r e 30d). Ev i d e n c e f o r e r o s i o n a r e l a g d e p o s i t s and scour c a s t s and molds. The r i v e r t r e n d was n o r t h e a s t t o southwest w i t h c o a r s e - g r a i n e d , i n - c h a n n e l d e p o s i t s o c c u r r i n g a l o n g t h i s l i n e . A s s o c i a t e d f i n e r - g r a i n e d l e v e e and c r e v a s s e d e p o s i t s f l a n k the c h a n n e l t o the n o r t h w e s t and the e a s t . The Lower "B" Channel appears t o have m i g r a t e d t o a more n o r t h e r l y c o u r s e due t o a v u l s i o n . The absence of an e x t e n s i v e c l a y p l u g i n d i c a t e s t h a t a chute c u t - o f f p r o c e s s o c c u r r e d i n which the r i v e r c u t a s t e e p e r , s h o r t e r r o u t e t o the sea t h r o u g h a p o i n t bar swale. A v u l s i o n caused i n t e r b e d d e d s i l t s t o n e s and mudstones t o be d e p o s i t e d as the c u r r e n t f l o w and c a p a c i t y d e c r e a s e d c a u s i n g the cha n n e l t o s i l t up. The n o r t h e a s t e r n c h a n n e l remained a c t i v e c r e a t i n g a d j a c e n t f l o o d p l a i n d e p o s i t s of i n t e r b e d d e d s i l t s t o n e s and s a n d s t o n e s . A s i m i l a r s i l t i n g up o f t h i s c h a n n e l l i k e l y a l l o w e d the e s t a b l i s h m e n t o f the "5L" peat swamp ( F i g u r e 30e). T h i s swamp devel o p e d a d j a c e n t t o the Upper 79 Figure 3 0 S u c c e s s i v e deposi t iona l env i ronments of Unit II s e d i m e n t s 80 "B" r i v e r system. The r i v e r was s i t u a t e d i n the so u t h w e s t e r n a r e a and a c t i v e l y eroded the peat swamp. I t i n t r o d u c e d d e t r i t u s i n t o the swamp as c r e v a s s e s r e s u l t i n g i n l a r g e s i l t s t o n e s p l i t s i n t he c o a l seam. The s h a l e y n a t u r e o f the c o a l i s a l s o an i n d i c a t i o n o f the nearness of the c h a n n e l . A v u l s i o n l e d t o the end of the "B" Channel phase of d e p o s i t i o n . F l o o d p l a i n mudstones then c o v e r e d the a r e a . A s t a b l e p e r i o d of a t l e a s t 5,000 y e a r s a l l o w e d the d e p o s i t i o n of the "5" peat swamp i n the so u t h w e s t e r n r e g i o n ( F i g u r e 3 0 f ) . T h i s swamp was f r e q u e n t l y f l o o d e d as i n d i c a t e d by i t s s h a l e y n a t u r e . The f l o o d w a t e r s e v e n t u a l l y drowned the pe a t s and d e p o s i t e d s i l t s and muds over them. These d e p o s i t s were used as a r o o t i n g medium by the "5U" pe a t s t h a t c o v e r e d the a r e a f o r a t l e a s t t h e next 18,000 y e a r s . As the f i r s t o f the c h a n n e l s , l a b e l l e d as "C" Channel, moved i n t o the ar e a i t eroded the "5U" peat swamp i n the n o r t h e r n r e g i o n ( F i g u r e 30g). Muds were i n t r o d u c e d i n t o the swamp from t h i s r i v e r system f o r m i n g the c o n s p i c u o u s s h a l e s p l i t i n the 5U Seam. The "C" r i v e r system d e p o s i t e d as many as 8 sandstone b o d i e s i n a b e l t t r e n d i n g n o r t h e a s t - s o u t h w e s t . The r i v e r m i g r a t e d a c r o s s t h i s f l o o d p l a i n numerous t i m e s . An u p l i f t i n the sourc e a r e a may have i n c r e a s e d sediment l o a d f o r c i n g the r i v e r t o seek a s t e e p e r , more d i r e c t r o u t e t o the se a . R e g a r d l e s s of the mechanism, the r i v e r appears t o have f a v o r e d the n o r t h -e a s t - s o u t h w e s t r o u t e through the s t u d y a r e a . P o i n t bar d e p o s i t s d e v e l o p e d from l a t e r a l m i g r a t i o n over c h a n n e l l a g d e p o s i t s . V e r t i c a l a c c r e t i o n d e p o s i t s o f s i l t s t o n e s , 81 F i g u r e 3 0 S u c c e s s i v e d e p o s i t i o n a l e n v i r o n m e n t s o f U n i t II s e d i m e n t s 82 carbonaceous s h a l e s and c o a l o f t e n o c c u r a t the t o p o f t h e s e d e p o s i t s . The p r e s e r v a t i o n p o t e n t i a l of the v e r t i c a l a c c r e t i p n d e p o s i t s i s low because of t h e p r o b a b i l i t y o f removal by s u c c e e d i n g c h a n n e l s . A s s o c i a t e d f i n e r - g r a i n e d f l o o d p l a i n sediments a re r e c o g n i z e d i n a r e a s d e v o i d o f c h a n n e l l i n g . Peat swamp "7" was e s t a b l i s h e d on top o f the "C" Channel d e p o s i t s ( F i g u r e 30h). I t was a d j a c e n t t o an a c t i v e c h a n n e l i n the n o r t h t h a t was breached s e v e r a l times r e s u l t i n g i n c r e v a s s e s p l a y d e p o s i t i o n i n the swamp. T h i s i s e v i d e n t from t h e numerous mudstone s p l i t s p r e s e n t i n the c o a l . The c e n t r a l a r e a o f the swamp may have been t o p o g r a p h i c a l l y h i g h e r than the s u r r o u n d i n g p e a t s because i t was l e a s t a f f e c t e d by the c r e v a s s e s p l a y s . I t s h i g h e r t o p o g r a p h i c p o s i t i o n may have been a r e s u l t of the "C" Channel sandstones compacting l e s s than a d j a c e n t f i n e r - g r a i n e d s e d i m e n t s . The c e n t r a l swamp ar e a c o n t i n u e d growing f o r a t l e a s t 80,000 y e a r s w i t h o u t i n t e r r u p t i o n from d e t r i t a l i n f l u x . The so u t h w e s t e r n r e g i o n appears t o have been i n c l o s e p r o x i m i t y t o the sediment s o u r c e as i n d i c a t e d by the h i g h c o n c e n t r a t i o n o f s i l t s t o n e p a r t i n g s . The "7" peat swamp was drowned by the "D" Channel f l o o d p l a i n s i l t s and muds ( F i g u r e 3 0 i ) . The n o r t h e a s t - s o u t h w e s t t r e n d i n g r i v e r system s i l t e d up and a s m a l l swamp (Coal Seam 8 ) , was e s t a b l i s h e d i n the e a s t - c e n t r a l and s o u t h w e s t e r n r e g i o n s . The swamp was p r e s e n t f o r o n l y 25,000 y e a r s , d u r i n g which time the "D" Channel o c c u r r e d s p o r a d i c a l l y n e x t t o i t i n t r o d u c i n g c r e v a s s e s p l a y sediments i n t o the swamp i n the southwest and n o r t h e a s t . 83 The end o f U n i t I I d e p o s i t i o n came w i t h the f l o o d i n g of "8" swamp and the b u r i a l under "D" Channel sediments. F l o o d b a s i n s i l t s and muds b l a n k e t e d the a r e a as the cha n n e l e s t a b l i s h e d a new r o u t e t o the sea. The sandstone b o d i e s t h a t a re so p r e v a l e n t i n t h i s U n i t a re not found i n the s u c c e e d i n g U n i t I I I . There i s no e v i d e n c e of sea l e v e l t r a n s g r e s s i o n d u r i n g the p e r i o d of M i s t Mountain s e d i m e n t a t i o n which would c r e a t e a h i g h e r base l e v e l and cause sediment d e p o s i t i o n upstream. The Columbian Orogeny was u p l i f t i n g t he source a r e a t o the west and so u t h and c o n t i n u e d t e c t o n i c p u l s e s may have i n c r e a s e d sediment i n p u t t o the r i v e r system l e a d i n g t o a l l u v i a t i o n d u r i n g d e p o s i t i o n of U n i t I I . I t i s unknown whether t e c t o n i c , c l i m a t i c o r b a s i n a l s u b s i d e n c e e f f e c t s t r i g g e r e d and i n f l u e n c e d the s h i f t i n g r i v e r p a t t e r n s o b s e r v e d i n U n i t I I . 2.4.5. U n i t I I I C h a r a c t e r i s t i c s The upper l i t h o s t r a t i g r a p h i c package c o m p r i s e s C o a l Seams 9, 11, 12, 13, 14 and 15 ( F i g u r e 8 ) . Channel sandstones a re l e s s common i n t h i s i n t e r v a l than i n e i t h e r U n i t s I or I I and t h e predominant sediments a re t h i n i n t e r b e d d e d s a n d s t o n e s , s i l t s t o n e s and mudstones. Co a l Seam Nine The t h i c k n e s s and geometry of Seam 9 are i l l u s t r a t e d i n f i g u r e s 9-13 (Map P o c k e t ) . The seam i s f r e e o f p a r t i n g s over most of the a r e a but has t h i n , s h a l e y s p l i t s i n the s o u t h w e s t e r n s e c t o r . The seam i s r e l a t i v e l y u n i f o r m i n t h i c k n e s s a t an 84 average o f 5 metres and i s b l o c k y t o sheared. The c o a l y mudstone p a r t i n g , where p r e s e n t , i s b l a c k ( N l ) , and e x h i b i t s p l a n a r l a m i n a t i o n s and f o s s i l p l a n t r emains. The g e o p h y s i c a l l o g t r a c e f o r Seam 9 i s a d i s t i n c t , b l o c k y low gamma r a y r e s p o n s e , w i t h g r a d a t i o n a l t o ab r u p t c o n t a c t s w i t h r o o f and f l o o r mudstones. Mudstone p a r t i n g s a re d i s t i n c t from the c o a l w i t h moderate t o h i g h gamma r a y v a l u e s . Nine To E l e v e n Seam I n t e r b u r d e n T h i s i n t e r v a l i s composed of i n t e r b e d d e d s a n d s tone, s i l t s t o n e and mudstone w i t h minor c o a l y beds. I t reaches i t s maximum t h i c k n e s s o f 52 metres i n the southwest and averages a p p r o x i m a t e l y 33 metres over the r e m a i n i n g a r e a . In o u t c r o p t h i s sequence i s mod e r a t e l y r e c e s s i v e and medium- t o d a r k - g r e y (N5-N3; F i g u r e 31). I r o n - r i c h bands and c o n c r e t i o n s a re r u s t y - o r a n g e (10 YR 6/6), and may form l e n s e s h a l f a metre t h i c k . The s i l t s t o n e s a r e medium- t o c o a r s e - g r a i n e d and f i s s i l e w i t h abundant f o s s i l i z e d p l a n t m a t e r i a l on bedding s u r f a c e s . O c c a s i o n a l v e r t i c a l l y - s t a n d i n g p e t r i f i e d t r e e t r u n k s o c c u r . P l a n a r l a m i n a t i o n s a re the most common s t r a t i f i c a t i o n and r o o t l e t s and b i o t u r b a t i o n commonly d i s t u r b t h e s e l a m i n a t i o n s . Sandstone beds are f i n e - g r a i n e d and medium-grey (N5). R i p p l e and p l a n a r l a m i n a t i o n s a re common and c l i m b i n g r i p p l e s and l o a d c a s t s o c c a s i o n a l l y o c c u r . C o a l y mudstone beds are p r e s e n t a t the top o f 9 Seam and a t the base o f Seam 11. On the g e o p h y s i c a l l o g response th e s e mudstones cause the b o u n d a r i e s of the 9-11 Seam i n t e r v a l t o be i n d i s t i n c t and g r a d a t i o n a l . The o v e r a l l g e o p h y s i c a l t r a c e i s i n d i s t i n c t as the sandstones and 85 s i l t s t o n e s grade i n t o one a n o t h e r . C o a l Seams E l e v e n Lower and Upper "Seam 11" i s composed o f two d i s t i n c t seams s e p a r a t e d by a s i l t s t o n e - m u d s t o n e i n t e r v a l ( F i g u r e 3 1 ) . The s t r a t i g r a p h y i s d i s p l a y e d i n f i g u r e s 9-13 (Map P o c k e t ) . Seam 11 Lower (11L) , ranges between 3 and 7 metres i n t h i c k n e s s a c r o s s the st u d y a r e a , e x c e p t i n the e a s t - c e n t r a l s e c t o r where i t t h i c k e n s t o 14 metres. In t h i s a r e a the seam i s a l s o f r e e of s i l t s t o n e or mudstone s p l i t s , whereas one or two s p l i t s a r e common i n a l l o t h e r a r e a s . The seam i s b l o c k y t o sheared and o f t e n s h a l e y . The r o o f r o c k i s commonly a medium- t o d a r k - g r e y (N5-N3) s i l t s t o n e . F o s s i l i z e d p l a n t m a t e r i a l i s abundant on bedding p l a n e s . R i p p l e and p l a n a r l a m i n a t i o n s a re the most common se d i m e n t a r y s t r u c t u r e s . The g e o p h y s i c a l l o g t r a c e r e f l e c t s the s h a l i n e s s o f the seam, i n most cases showing i n d i s t i n c t low t o moderate gamma r a y peaks. In o t h e r a r e a s where 11L and 11 Upper (11U) , seams are t h i c k and s e p a r a t e d by o n l y a t h i n , s h a l e y band the gamma-ray response i s w e l l - d e f i n e d and low ( F i g u r e 3 2 ) . The 11L t o 11U i n t e r v a l i s composed of i n t e r b e d d e d s i l t s t o n e and mudstone. The maximum t h i c k n e s s (32 metres) i s reached i n the n o r t h e a s t where the e n t i r e i n t e r v a l i s s i l t s t o n e . The i n t e r v a l t h i n s and s h a l e s - o u t i n a l l o t h e r a r e a s . The t h i n n e s t a r e a , 1 metre, c o r r e s p o n d s t o the t h i c k e s t r e g i o n of 11L Seam. The s i l t s t o n e s and mudstones are r e c e s s i v e i n o u t c r o p and d i s p l a y f i s s i l e and s p h e r o i d a l w e a t h e r i n g t e x t u r e s . Rusty w e a t h e r i n g i s a s s o c i a t e d w i t h i r o n - r i c h l e n s e s and c o n c r e t i o n s . 86 L I T H O L O G Y & GRAIN SIZE C L S VF F M i i I i 1 _ S T R U C T U R E R E M A R K S 30 -\ 20 10 -t y. an y-~u~ = ^ X y\ o y^ o y\ nrr y^ o = y\ y- $ \y^ = CD y^ = 13 S e a m 12 S e a m C h a n n e l f l o o r 11 U p p e r s e a m 11 S e a m 9 S e a m 8 S e a m A b r u p t t o g r a d a t i o n a l c o n t a c t Figure 31 E A G L E S W T R A V E R S E 4 - 6 Sed iments of Unit II and Unit III 87 Sedimentary s t r u c t u r e s p r e s e n t i n c l u d e p l a n a r and r i p p l e l a m i n a t i o n s , c l i m b i n g r i p p l e s and l o a d c a s t s . S o f t -sediment sl u m p i n g and b u r r o w i n g a re l o c a l l y p r e s e n t ( F i g u r e 3 2). The g e o p h y s i c a l l o g response i s i n d i s t i n c t , showing g r a d a t i o n a l moderate t o h i g h gamma r a y peaks. C o a l Seam 11U i s c o n s t a n t i n t h i c k n e s s a t 4 t o 5 metres and i t i s r e l a t i v e l y f r e e o f p a r t i n g s . In o u t c r o p i t i s b l o c k y and the predominant l i t h o t y p e s a r e v i t r a i n and c l a r a i n . The lower c o n t a c t i s g r a d a t i o n a l from c o a l y mudstone or s i l t s t o n e t o c o a l w h i l e the upper c o n t a c t i s a b r u p t t o e r o s i o n a l ( F i g u r e s 31, 32 and 3 3 ) . The g e o p h y s i c a l response i s a b l o c k y , low gamma t r a c e w i t h a g r a d a t i o n a l lower boundary and a more a b r u p t upper boundary. Seam E l e v e n Upper t o Twelve I n t e r b u r d e n The geometry and c o n f i g u r a t i o n of t h i s i n t e r v a l a r e i l l u s t r a t e d i n f i g u r e s 9-13 (Map P o c k e t ) . I t v a r i e s i n t h i c k n e s s from 2 metres i n the n o r t h e a s t t o 41 metres i n the c e n t r a l and e a s t e r n a r e a s . T h i s sequence i s p r e d o m i n a n t l y s i l t s t o n e e x c e p t i n the c e n t r a l a r e a where a t h i n sandstone body o c c u r s . I n o u t c r o p the f i n e - t o medium-grained s i l t s t o n e i s d a r k - g r e y (N3), commonly showing a r u s t y - c o l o r e d w e a t h e r i n g p r o d u c t . C l i m b i n g r i p p l e s and p l a n a r and r i p p l e l a m i n a t i o n s and p l a n a r c r o s s b e d d i n g a r e common s e d i m e n t a r y f e a t u r e s . The s i l t s t o n e s show f i s s i l i t y and s p h e r o i d a l w e a t h e r i n g of i r o n - r i c h c o n c r e t i o n s . S o f t - s e d i m e n t s l u m p i n g and b i o t u r b a t i o n caused d i s t u r b a n c e o f bed d i n g ( F i g u r e 32). The g e o p h y s i c a l l o g s i g n a t u r e o f the s i l t s t o n e s i s a h i g h 88 Figure 3 2 D D H 1 7 5 8 S E D I M E N T S O F UNIT I I I 89 L I T H O L O G Y & GRAIN SIZE C L S V F F M _1 i i_ 160 -•-1 5 0 1 1 0 1 0 0 -6 0 -2 0 10 -: 0 - T ^ y\ t. -- o y\ 777T C D = y^ $ = y^ TUT = y^ S T R U C T U R E y^ IT y\ y^ - 7T7T R E M A R K S 15 S e a m C o l o u r b a n d e d L e n s e s to w e s t M i n o r s e a m S a n d s t o n e l e n s e s - 0 . 5 m t h i c k , c h a n n e l l a g C l i m b i n g r i p p l e s a n d r o o t l e t s in s a n d s t o n e M i n o r s e a m 14 U p p e r s e a m 14 S e a m 14 L o w e r s e a m 13 S e a m 12 S e a m 11 U p p e r s e a m F i g u r e 3 3 T A Y L O R PIT T R A V E R S E Sediments of Unit III 90 t o moderate gamma r a y v a l u e . I n d i s t i n c t c o n t a c t s o c c u r where s i l t s t o n e s grade v e r t i c a l l y i n t o mudstones, but b o u n d a r i e s a re d i s t i n c t and a b r u p t where s i l t s t o n e s are o v e r l a i n by sandstones ( F i g u r e s 32 and 33). In o u t c r o p the sandstones a re f i n e - t o medium-grained and medium-grey (N5). I r o n w e a t h e r i n g p r o d u c t s s t a i n t he s u r f a c e w i t h r u s t y p a t c h e s . B a s a l c o n t a c t s a r e e r o s i o n a l w i t h r i p - u p c l a s t s , p e t r i f i e d wood fragments and l o a d c a s t s as e v i d e n c e of s c o u r i n g . Sandstones e x h i b i t c l i m b i n g r i p p l e s and r i p p l e l a m i n a t i o n s , p l a n a r c r o s s b e d d i n g and p l a n a r l a m i n a t i o n s . Sediments have been d i s t u r b e d by slump i n g and b u r r o w i n g . The g e o p h y s i c a l l o g response f o r t h i s i n t e r v a l shows a h i g h gamma r a y v a l u e f o r mudstones, a moderate response f o r s i l t s t o n e s and s i l t y sandstone and a low response f o r c l e a n e r sandstones ( F i g u r e 3 2 ) . The c o n t a c t s o f i n d i v i d u a l beds are commonly i n d i s t i n c t because o f r e p e t i t i o u s g r a d i n g between l i t h o l o g i e s . Sharp, e r o s i o n a l c o n t a c t s a r e a r e s u l t of s c o u r i n g of u n d e r l y i n g sediments d u r i n g sandstone d e p o s i t i o n . C o a l Seam Twelve A c r o s s the e a s t e r n s e c t o r o f the stu d y a r e a 12 Seam i s u n i f o r m l y 6 metres t h i c k w i t h e i t h e r one or two p a r t i n g s . However, i n the c e n t r a l a r e a 12 Seam i s t r u n c a t e d by a sandstone c h a n n e l and i s reduced t o 1.5 metres t h i c k . In o u t c r o p the predominant l i t h o t y p e s a r e v i t r a i n and c l a r a i n . The v i t r a i n appears s h i n y and b l o c k y i n t e x t u r e , whereas the c l a r a i n i s commonly sh e a r e d . The c o a l y mudstone p a r t i n g s e x h i b i t p l a n a r l a m i n a t i o n s and abundant p l a n t f o s s i l s 91 on b edding p l a n e s . On the g e o p h y s i c a l l o g t h i s seam has a d i s t i n c t , b l o c k y form i n the low gamma range. The lower c o n t a c t i s g r a d a t i o n a l from s h a l y f l o o r r o c k and the upper c o n t a c t i s s h a r p e r w i t h muddy s i l t s t o n e s . Twelve To T h i r t e e n Seam I n t e r b u r d e n F i g u r e s 9-13 (Map P o c k e t ) , i l l u s t r a t e the geometry and c o m p o s i t i o n o f the 12 t o 13 Seam i n t e r b u r d e n . I t i s p r e d o m i n a n t l y a s i l t s t o n e - m u d s t o n e i n t e r v a l w i t h a minor sandstone body t r e n d i n g n o r t h - s o u t h i n the w e s t e r n p a r t of the stud y a r e a . The sandstone body i s more l i m i t e d i n v e r t i c a l and a r e a l e x t e n t than the sandstone b o d i e s t h a t o c c u r i n U n i t s I and I I . The o v e r a l l t h i c k n e s s o f the i n t e r v a l i s g r e a t e s t i n areas of sandstone o c c u r r e n c e . The maximum t h i c k n e s s i s 41 metres and the minimum t h i c k n e s s , i n the n o r t h e a s t e r n s e c t o r , i s 5 metres. The sandstone body averages 6 metres i n t h i c k n e s s . The ch a n n e l f i l l i s f i n e - g r a i n e d s i l t y sandstone t h a t i s br o w n i s h - g r e y (5 YR 4/1), on a f r e s h s u r f a c e . The b u f f w e a t h e r i n g c o l o r (10 YR 8/2), i s due t o the presence o f i r o n m i n e r a l s . P l a n a r and r i p p l e l a m i n a t i o n s , c l i m b i n g r i p p l e s , t a n g e n t i a l c r o s s b e d d i n g and l o a d c a s t s a re common se d i m e n t a r y s t r u c t u r e s . B u r r o w i n g and s o f t - s e d i m e n t s l u m p i n g have d i s t u r b e d the s e d i m e n t s . C o a l y p a r t i n g s and f o s s i l i z e d p l a n t s a re common on bedding p l a n e s . The s i l t s t o n e s i n o u t c r o p a re medium- t o d a r k - g r e y (N5-N3). P l a n a r and r i p p l e l a m i n a t i o n s a re the predominant s e d i m e n t a r y f e a t u r e s . R o o t l e t s , b i o t u r b a t i o n and s o f t - s e d i m e n t s l u m p i n g have 92 d i s t u r b e d the sediment. The c o a l y mudstones a r e b r o w n i s h - g r e y (5 YR 4/1), p l a n a r l a m i n a t e d and commonly f i s s i l e . Where sandstone b o d i e s o c c u r , the g e o p h y s i c a l l o g shows a b l o c k y , low gamma r a y v a l u e w i t h a sharp base and a g r a d a t i o n a l upper c o n t a c t . The sandstones f i n e upward i n t o the moderate gamma r a y response i n d i c a t i v e of s i l t s t o n e s and f i n a l l y t o h i g h gamma mudstones. In some cases the mudstones and s i l t s t o n e s appear t o coarsen-upward t o sa n d s t o n e s . The sandstones show a g r a d a t i o n a l base and an ab r u p t upper c o n t a c t . C o a l Seam T h i r t e e n " T h i r t e e n Seam" i s a complex sequence composed o f s e v e r a l c o a l seams and i n t e r s e a m s i l t s t o n e s and mudstones. The geometry i s d e p i c t e d i n f i g u r e s 9-13 (Map P o c k e t ) . The composite c o a l t h i c k n e s s ranges from 4 t o 9 metres. In o u t c r o p , "13 Seam" i s a s h a l e y , sheared c o a l t h a t changes l a t e r a l l y t o a mudstone or c o a l y s h a l e . The i n t e r s e a m mudstones a re d a r k - g r e y t o b l a c k (N3-N1), and e x h i b i t c o a l y , p l a n a r l a m i n a t i o n s . In some a r e a s , dark grey (N3-N1) s i l t s t o n e s and f i n e - g r a i n e d , dark g r e y s i l t y sandstones make up the i n t e r s e a m a r e a s . The sandstones a r e b i o t u r b a t e d , c o n v o l u t e bedded and s a n d - f i l l e d burrows o c c u r . The s t r u c t u r e s i n t he s i l t s t o n e s a r e l i m i t e d t o p l a n a r l a m i n a t i o n s . On the g e o p h y s i c a l l o g , the "13 Seam" p r o f i l e i s i n d i s t i n c t . Both upper and lower b o u n d a r i e s a r e g r a d a t i o n a l w i t h c o a l y mudstones. The c o a l seams show up as low t o moderate gamma 93 r a y peaks, dependant on the s h a l e c o n t e n t . Rock p a r t i n g s a r e d i s t i n g u i s h e d by t h e i r h i g h e r gamma r a y r e s p o n s e s . T h i r t e e n To F o u r t e e n Seam I n t e r b u r d e n The 13 t o 14 Seam i n t e r v a l i s composed o f s i l t s t o n e , mudstone and s e v e r a l t h i n c o a l seams. The i n t e r v a l ranges i n t h i c k n e s s from 20 metres i n the no r t h w e s t t o 36 metres i n the s o u t h - c e n t r a l a r e a . The geometry and c o n f i g u r a t i o n are shown i n f i g u r e s 9-13 (Map P o c k e t ) . In o u t c r o p the s i l t s t o n e s and mudstones are l i g h t - t o medium-grey (N7-N5), w i t h o c c a s i o n a l r u s t y c o l o r e d patches and c o n c r e t i o n s . Sedimentary s t u c t u r e s o b s e r v e d i n c l u d e p l a n a r and r i p p l e l a m i n a t i o n s , l o a d c a s t s , a r g i l l a c e o u s c l a s t s and p l a n a r c r o s s b e d s . Sediment d i s t u r b a n c e i s e v i d e n t from b i o t u r b a t i o n and s o f t - s e d i m e n t s l u m p i n g . C o a l Seams F o u r t e e n Lower, Main and Upper The 14 Seam sequence can be d i v i d e d i n t o l o w e r , main and upper seams. The i n t e r s e a m a r e a s a re p r e d o m i n a n t l y s i l t s t o n e s and mudstones w i t h s c a t t e r e d sandstone b o d i e s ( F i g u r e 33). F o u r t e e n Lower ( 1 4 L ) , reaches a maximum t h i c k n e s s of 5 metres i n the n o r t h w e s t . I t s h a l e s - o u t t o the n o r t h e a s t and t h i n s t o the south and s o u t h e a s t . In o u t c r o p i t appears b l o c k y t o s h e a r e d . The predominant l i t h o t y p e i s v i t r a i n . On the g e o p h y s i c a l l o g 14L may appear o n l y s l i g h t l y lower i n response than a d j a c e n t muddy s i l t s t o n e s and does not have a c h a r a c t e r i s t i c response as many of the o t h e r c o a l seams do. The i n t e r s e a m a r e a from 14L t o 14 Main seam (14M), i s 94 p r e d o m i n a n t l y s i l t s t o n e and mudstone w i t h a t h i n sandstone body ( F i g u r e 3 4 ) . I t v a r i e s i n t h i c k n e s s from 21 metres i n the e a s t t o 30 metres i n the no r t h w e s t s e c t o r . The sandstone i s f i n e - g r a i n e d and medium-grey (N5). Load c a s t s and a r g i l l a c e o u s r i p - u p c l a s t s o f t e n o c c u r on the a b r u p t b a s a l c o n t a c t ( F i g u r e 34). P l a n a r c r o s s b e d s and r i p p l e l a m i n a t i o n s a r e the p r i m a r y s t u c t u r e s . B i o t u r b a t i o n has l o c a l l y d e s t r o y e d o r i g i n a l b e d d i n g . The s i l t s t o n e s a r e l i g h t - t o medium-grey (N7-N5). P l a n a r and r i p p l e l a m i n a t i o n s , c o n c r e t i o n s , l o a d c a s t s , p l a n a r c r o s s b e d s , b i o t u r b a t i o n and r o o t l e t s are the most common sed i m e n t a r y f e a t u r e s . Mudstones a re b l a c k ( N l ) , and have abundant p l a n t f o s s i l s on the bedding p l a n e s . F i g u r e 34 i l l u s t r a t e s the low gamma r a y v a l u e o f the sandstone body, the h i g h gamma response of the o v e r l y i n g s i l t s t o n e s and the moderate gamma o f the c o a l y s h a l e o f 14M Seam. Coa l Seam 14M i s 2 metres t h i c k and f r e e of p a r t i n g s i n the n o r t h e r n a r e a . I t i n c r e a s e s i n t h i c k n e s s and number o f p a r t i n g s i n a s o u t h e r l y d i r e c t i o n . The predominant l i t h o t y p e s a r e v i t r a i n and c l a r a i n which g i v e the c o a l a b l o c k y t e x t u r e . A c h a r a c t e r i s t i c g e o p h y s i c a l response can be seen by comparing f i g u r e s 34 and 35. Seam 14M has two low gamma r a y peaks s e p a r a t e d by a moderate mudstone peak. The lower c o n t a c t i s more g r a d a t i o n a l and i n d i s t i n c t t h a n the upper c o n t a c t . The i n t e r s e a m sequence from 14M t o 14 Upper (14U) , i s s i m i l a r t o the p r e v i o u s two i n t e r s e a m a r e a s . S i l t s t o n e s and 95 F i g u r e 3 4 D D H 1 7 5 7 S E D I M E N T S O F U N I T III 96 mudstones predominate w i t h minor s i l t y sandstone b o d i e s . The sequence i s t h i c k e s t i n the southwest a t 30 metres and d e c r e a s e s toward a l l o t h e r s e c t o r s . The s i l t s t o n e s a r e d a r k - g r e y t o b l a c k (N3-N1). P l a n a r and r i p p l e l a m i n a t i o n s are common s t r u c t u r e s . The sediments have been d i s t u r b e d by b u r r o w i n g , r o o t l e t s and s o f t - s e d i m e n t s l u m p i n g ( F i g u r e 3 5 ) . The s i l t y sandstones a re f i n e - g r a i n e d , medium-grey (N5), and u s u a l l y o n l y a metre and a h a l f t h i c k . They may have ab r u p t t o g r a d a t i o n a l bases and f i n e upwards t o s i l t s t o n e s , mudstones and c o a l s . Sedimentary s t r u c t u r e s i n c l u d e p l a n a r c r o s s b e d d i n g , c l i m b i n g r i p p l e s , and r i p p l e l a m i n a t i o n s . D i s t u r b a n c e o f sediments has been caused by s o f t - s e d i m e n t s l u m p i n g , sand v o l c a n o e s , r o o t growth and b u r r o w i n g . Load c a s t s and a r g i l l a c e o u s r i p - u p c l a s t s g i v e some e v i d e n c e of c h a n n e l l i n g . C o a l y p a r t i n g s and w i s p s , w i t h a s s o c i a t e d p y r i t e c r y s t a l s , a r e common i n t h e sandstones ( F i g u r e 3 5 ) . Mudstones i n t h i s sequence are c o a l y , b l a c k ( N l ) , and have abundant p l a n t f o s s i l s on p l a n a r l a m i n a t i o n s . F i g u r e s 34 and 35 i l l u s t r a t e t y p i c a l gamma r a y r e s p o n s e s . The sandstone b o d i e s , where t h i n , do not appear d i s t i n c t i v e as compared t o a d j a c e n t s i l t s t o n e s . However, when they a re up t o 5 metres t h i c k , which i s r a r e , low gamma r a y v a l u e s d i s t i n g u i s h them from h i g h e r gamma s i l t s t o n e s . The i n t e r v a l has an ab r u p t c o n t a c t w i t h 14U Seam. Co a l Seam 14U v a r i e s i n t h i c k n e s s from 1.5 metres i n the e a s t t o 7.5 metres i n the southwest. In o u t c r o p the c o a l i s b l o c k y t o sheared and has.up t o 3 mudstone p a r t i n g s . The F i g u r e 3 5 DDH 1 7 5 2 SEDIMENTS OF UNIT I I I 98 g e o p h y s i c a l l o g t r a c e ( F i g u r e 3 5 ) , shows a c h a r a c t e r i s t i c low gamma r a y peak w i t h an a b r u p t upper c o n t a c t . The b a s a l c o n t a c t i s u s u a l l y g r a d a t i o n a l from s i l t y mudstone. F o u r t e e n To F i f t e e n Seam I n t e r b u r d e n The i n t e r b u r d e n sequence of i n t e r b e d d e d s a n d s t o n e , s i l t s t o n e and mudstone i s 44 metres t h i c k i n the c e n t r a l a r e a and t h i n s t o 13 metres i n the southwest. A t y p i c a l l e n s i n g c r e v a s s e - c h a n n e l sandstone i s shown i n p l a t e 1. The l e n s i s about 10 metres i n t h i c k n e s s and t r u n c a t e s u n d e r l y i n g s i l t s t o n e s and mudstones. The sandstones are v e r y f i n e - t o f i n e - g r a i n e d and medium- t o d a r k - g r e y (N5-N3). I r o n - r i c h c o n c r e t i o n s and l e n s e s are r u s t y c o l o r e d . P l a n a r c r o s s b e d d i n g , c l i m b i n g r i p p l e s and r i p p l e l a m i n a t i o n s are the most common s t r u c t u r e s . Load c a s t s , a r g i l l a c e o u s r i p - u p c l a s t s and p l a n t f o s s i l s o c c u r i n g i n c h a n n e l l a g d e p o s i t s are e v i d e n c e of s c o u r i n g . The sandstones f i n e - u p w a r d t o c o a l y s i l t s t o n e s t h a t are s i m i l a r i l y i r o n s t a i n e d but are f i s s i l e and r e c e s s i v e . R i p p l e and p l a n a r l a m i n a t i o n s and p l a n a r c r o s s b e d s are the predominant s t r u c t u r e s . The g e o p h y s i c a l l o g response i s i n d i s t i n c t because of the i n t e r b e d d e d , g r a d a t i o n a l n a t u r e of the s e d i m e n t s . C o a l Seam F i f t e e n T h i s seam i s a p rominent, t h i c k seam a t the t o p o f the sequence s t u d i e d . Where observ e d i n o u t c r o p i t i s 5 t o 9 metres t h i c k w i t h one t o t h r e e main p a r t i n g s . I t appears t o be t h i c k e s t and has the fewest p a r t i n g s i n the w e s t e r n p a r t o f the s t u d y P l a t e 1 P r o x i m a l C r e v a s s e S a n d s t o n e T r u n c a t i n g F l o o d B a s i n S i l t s t o n e a n d M u d s t o n e 100 a r e a . The g e o p h y s i c a l l o g s i g n a t u r e can be b l o c k y and w e l l d e f i n e d i f t h e r e a re no p a r t i n g s . As p a r t i n g s i n c r e a s e t h i s s i g n a t u r e becomes g r a d a t i o n a l and i n d i s t i n c t . 2.4.6. U n i t I I I Sedimentology U n i t I I I began w i t h the development o f 9 Seam peat swamp on the f l o o d b a s i n sediments t h a t succeeded "D" Channel ( F i g u r e 36a). The peat used the u n d e r l y i n g muds as a r o o t i n g medium and c o n t i n u e d t o grow f o r a t l e a s t 30,000 y e a r s . S p o r a d i c i n t e r r u p t i o n o f peat growth o c c u r r e d as f l o o d b a s i n d e p o s i t s were d e r i v e d from a s o u t h w e s t e r n s o u r c e . The h i g h l y o r g a n i c n a t u r e o f the s h a l e s p l i t s s u g g e s t s t h a t v e r y t h i n l a y e r s o f mud were d e p o s i t e d from s u s p e n s i o n onto peat s u r f a c e s . S u r f a c e l i t t e r would be i n c o r p o r a t e d i n t o the mud l a y e r s p r i o r t o d e p o s i t i o n o f s u c c e e d i n g l a m i n a t o n s . The "9" peat swamp was b u r i e d by p r o l o n g e d f l o o d i n g events t h a t d e p o s i t e d muds from s u s p e n s i o n t o form p l a n a r l a m i n a t e d mudstones. T h i s a r e a was i n u n d a t e d by f l o o d waters t h a t d e p o s i t e d c r e v a s s e and d i s t a l s p l a y sediments i n t o v e g e t a t e d a r e a s ( F i g u r e 36b). The r a t e of d e p o s i t i o n must have been h i g h because some t r e e s a re p r e s e r v e d as v e r t i c a l , f o s s i l i z e d stumps. Ponds were common on the f l o o d p l a i n and t h e i r sediments a r e p r e s e r v e d as i n t e r b e d d e d sequences o f l a m i n a t e d s i l t s t o n e s and mudstones. The c e s s a t i o n of f l o o d i n g a l l o w e d the development of the 11 Seam peat swamp on the f l o o d p l a i n ( F i g u r e 3 6 c ) . Peat growth was 101 Figure 36 S u c c e s s i v e depos i t iona l environments of Unit III sed iments 102 e s t a b l i s h e d f o r a t l e a s t 25,000 y e a r s b e f o r e b e i n g i n t e r r u p t e d by a f l o o d i n g or ponding event which d e p o s i t e d l a m i n a t e d muds over most o f the a r e a . The e a s t - c e n t r a l a r e a remained a t o p o g r a p h i c a l l y h i g h e r a r e a than the s u r r o u n d i n g f l o o d e d a r e a and a l l o w e d c o n t i n u o u s peat growth f o r a t l e a s t 85,000 y e a r s . The s h a l i n e s s o f the seam su g g e s t s a c o n t i n u o u s d e t r i t a l i n p u t d u r i n g peat growth. T h i s d e t r i t u s may have been c a r r i e d i n by f l o o d w a t e r s from an a d j a c e n t stream system. The i n t r o d u c t i o n o f s i l t l o b e s from the n o r t h e a s t and southwest s u g g e s t s t h a t stream systems were a c t i v e i n those d i r e c t i o n s . The c u l m i n a t i o n o f "11L" peat growth came w i t h the i n t r o d u c t o n o f c r e v a s s e s p l a y l o b e s and the a s s o c i a t e d d i s t a l s p l a y muds ( F i g u r e 36d). C l i m b i n g and r i p p l e l a m i n a t i o n s i n the s i l t s t o n e s suggest a lower f l o w regime c u r r e n t . C u r r e n t s c a r r i e d s i l t s and muds from p r o x i m a l t o d i s t a l p o s i t i o n s where p l a n a r l a m i n a t i o n s i n d i c a t e p a r t i c l e d e p o s i t i o n from s u s p e n s i o n . Peat swamp "11U" was e s t a b l i s h e d on the f l o o d b a s i n muds and c o n t i n u e d t o grow f o r a t l e a s t 30,000 y e a r s ( F i g u r e 36e). I t had i n t e r r u p t i o n s o f d e t r i t a l muds from n o r t h e a s t and southwest s o u r c e s a d d i n g e v i d e n c e t o the e x i s t e n c e o f stream systems i n those a r e a s . The l a c k o f a s h a l e y c h a r a c t e r of the seam su g g e s t s t h a t f l o o d i n g events were more i s o l a t e d than i n the p e r i o d of d e p o s i t i o n o f 11L Seam where d e t r i t a l i n f l u x seemed t o be c o n s t a n t . Growth of "11U" peat swamp was a b r u p t l y d i s c o n t i n u e d as a s m a l l c h a n n e l d e v e l o p e d i n the ar e a ( F i g u r e 3 6 f ) . The abr u p t t o e r o s i o n a l c o n t a c t w i t h the o v e r l y i n g s i l t s t o n e s a t t e s t s t o the 103 Figure 36 S u c c e s s i v e deposit ional environments of Unit III sed iments 104 s w i f t n e s s o f t h i s e v e n t . S i l t s and muds were d e p o s i t e d i n advance of the cha n n e l moving i n t o the a r e a . The c l i m b i n g and r i p p l e l a m i n a t i o n s and s o f t - s e d i m e n t s l u m p i n g suggest a moderate c u r r e n t v e l o c i t y p r o x i m a l t o the main ch a n n e l i n a c r e v a s s e s p l a y s i t u a t i o n . S i l t s t o n e s were sc o u r e d by the c u r r e n t s t h a t formed the c h a n n e l . The s e d i m e n t a r y f e a t u r e s p r e s e n t suggest an i n i t i a l s w i f t , e r o s i v e c u r r e n t t h a t e v e n t u a l l y s u b s i d e d a l l o w i n g a s i l t i n g up o f the s m a l l c h a n n e l . P l a n a r c r o s s b e d d i n g i s common a t the base of the s e s a n d s t o n e s , w h i l e c l i m b i n g r i p p l e s and p l a n a r l a m i n a t i o n s i n c r e a s e upwards i n d i c a t i n g a drop i n c u r r e n t energy and a c o r r e s p o n d i n g d e c r e a s e i n b e d l o a d . The g r a d u a l s i l t i n g up of the c h a n n e l a l l o w e d peat swamp "12" t o ta k e r o o t on the f l o o d b a s i n s i l t s and muds ( F i g u r e 36g). I t seems t o have been a f f e c t e d by the p o s i t i o n of the ch a n n e l because above the c h a n n e l i n the c e n t r a l a r e a the c o a l i s the t h i n n e s t . I f the p a l e o c h a n n e l remained t o p o g r a p h i c a l l y h i g h , o x i d a t i o n and e r o s i o n would remove much o f the peat growth, c a u s i n g a t h i n n e r c o a l a r e a . Laminated mudstone s p l i t s may i n d i c a t e a r e a s where ponds s p o r a d i c a l l y c o v e r e d the p e a t . Abundant p l a n t m a t e r i a l on the mudstone bedding p l a n e s suggests a slow r a i n o f p l a n t p a r t i c l e s from the pond wat e r s onto the muddy bottom. The upper c o n t a c t of 12 Seam i s a b r u p t w i t h o v e r l y i n g a r g i l l a c e o u s s i l t s t o n e s a t t e s t i n g t o the s w i f t n e s s o f the s i l t - c a r r y i n g c u r r e n t . Channel "E" developed i n the a r e a d e p o s i t i n g sands and f i n e r - g r a i n e d m a t e r i a l s onto "12" peat swamp and i n p l a c e s 105 Figure 3 6 S u c c e s s i v e deposit ional environments of Unit III sed iments 106 e r o d i n g the p e a t s ( F i g u r e 36h). The t h i n n e s t c o a l (3 m e t r e s ) , o c c u r s r o u g h l y p a r a l l e l t o and beneath the c h a n n e l ' s t h i c k e s t sandstones (>25 m e t r e s ) . Towards the c h a n n e l margins, c o a l t h i c k n e s s i n c r e a s e s up t o 9 metres. The seam may a l s o be t h i n i n t h i s NW-SE t r e n d because of d e p o s i t i o n on a t o p o g r a p h i c a l l y h i g h e r area a s s o c i a t e d w i t h the s m a l l e r s a n d - f i l l e d c h a n n e l p r e c e d i n g i t ( F i g u r e 3 7 ) . High ash v a l u e s (20-30%), o c c u r a l o n g the "E" Channel t r e n d and d e c r e a s e i n a r e a s away from i t . High ash v a l u e s i n the n o r t h e a s t may be a s s o c i a t e d w i t h ponds o c c u r r i n g on 12 Seam backswamp ( F i g u r e 3 7 ) . A lower f l o w regime c u r r e n t was c a p a b l e of c a r r y i n g f i n e -g r a i n e d sand and d e p o s i t i n g i t i n m i g r a t i n g c u r r e n t r i p p l e s . As the c u r r e n t d e c r e a s e d i n s t r e n g t h i t d e p o s i t e d r i p p l e and l a m i n a t e d s i l t s . The r o o t l e t s and b i o t u r b a t i o n t h a t commonly o c c u r i n the l a m i n a t e d s i l t s i n d i c a t e a q u i e t environment of d e p o s i t i o n , p o s s i b l y on a l e v e e . The r i p p l e d and slumped s i l t s may have been d e p o s i t e d i n p r o x i m a l c r e v a s s e s p l a y p o s i t i o n s . The c o a r s e n i n g - u p w a r d sequences of mudstone, s i l t s t o n e t o sand-s t o n e may have been formed when s p l a y s prograded i n t o s t a n d i n g b o d i e s of w a t e r , such as the s m a l l ponds t h a t formed on the f l o o d p l a i n . The s i l t i n g up or movement of "E" Channel out of the a r e a a l l o w e d the "13" peat swamp t o d e v e l o p ( F i g u r e 3 6 i ) . P e a t s r o o t e d i n the r i c h muds of "E" Channel's f l o o d b a s i n . Peat growth was f r e q u e n t l y i n t e r r u p t e d by f l o o d i n g e v e n t s t h a t d e p o s i t e d c l a y p a r t i c l e s from s u s p e n s i o n onto the peat s u r f a c e . L e ss f r e q u e n t l y , s i l t s and sands of d i s t a l s p l a y o r i g i n were 107 N N E T C H A N N E L S A N D S T O N E 0 - 1 0 metres 1 0 - 2 0 met res > 20 metres 9 \ N 3 3 7 N s V \ \ 4s. , s \ \ \ \ \ 7. 7N\K n n n n v \ N^N\\\\ / r i i ./ 3 4 « Raw coal ash content (weight %) •—9 C o a l s e a m 12 thickness (metres) Diamond and rotary drill holes • Holes u s e d for c r o s s s e c t i o n s o C o r e d holes 500 500 1000 m e t r e s Figure 37 " E " c h a n n e l isol i th map and C o a l S e a m 12 i s o p a c h map 108 d e p o s i t e d by weak c u r r e n t s . E x t e n s i v e b u r r o w i n g a c t i v i t y i n l a m i n a t e d s i l t s and muds i n d i c a t e a q u i e t d e p o s i t i o n a l environment f o r t h e s e s e d i m e n t s , such as a f l o o d b a s i n pond. The growth of t h i s peat swamp c o n t i n u e d s p o r a d i c a l l y f o r a t l e a s t 55,000 y e a r s and ceased t o e x i s t when i t was f l o o d e d by w a t e r s from an a d j a c e n t r i v e r system. The d e p o s i t i o n a l environments on t h i s f l o o d p l a i n i n c l u d e d ponds, swamps and d i s t a l s p l a y s ( F i g u r e 3 6 j ) . The d i s t a l s p l a y c u r r e n t s produced crossbedded and r i p p l e d s i l t s . These c u r r e n t s were s t r o n g enough t o scour i n t o u n d e r l y i n g sediments and were accompanied by s o f t - s e d i m e n t s l u m p i n g i n u n c o n s o l i d a t e d s i l t s . In the ponds p l a n a r l a m i n a t e d muds formed as c l a y p a r t i c l e s s e t t l e d from s u s p e n s i o n . The c o a l beds i n t h i s i n t e r v a l were a r e s u l t o f peat e s t a b l i s h m e n t i n areas s l i g h t l y h i g h e r than ponds on the f l o o d p l a i n . The e s t a b l i s h m e n t o f "14L" peat swamp o c c u r r e d on o n l y p a r t o f the f l o o d b a s i n ( F i g u r e 36k). F l o o d i n g events i n t r o d u c e d c l a y p a r t i c l e s i n t o the peat swamp and t h i s g i v e s 14L Co a l Seam a s h a l e y n a t u r e . T h i s peat swamp was b u r i e d when a minor c h a n n e l d e v e l o p e d i n the ar e a c o v e r i n g the peats w i t h s i l t s and muds ( F i g u r e 361). An e r o s i v e c u r r e n t s c o u r e d i n t o u n d e r l y i n g f l o o d b a s i n sediments and d e p o s i t e d sand i n m i g r a t i n g r i p p l e s . S i l t s were d e p o s i t e d i n r i p p l e s as the c u r r e n t waned i n i n t e n s i t y . Laminated mudstones were formed from the s e t t l i n g of c l a y p a r t i c l e s from s u s p e n s i o n from overbank and c r e v a s s e f l o w s . Root p e n e t r a t i o n and b u r r o w i n g a c t i v i t y i n d i s t a l s p l a y s i l t s and 109 Figure 36 S u c c e s s i v e deposi t ional environments of Unit III sediments 110 muds are i n d i c a t i v e o f a q u i e t environment o f d e p o s i t i o n . Peat swamp "14M" r o o t e d i n f l o o d b a s i n s i l t s and muds, but was s t a b l e f o r o n l y 18,000 y e a r s ( F i g u r e 36m). I t was i n t e r r u p t e d s e v e r a l times by ponding e v e n t s t h a t d e p o s i t e d l a y e r e d c l a y s onto the peat s u r f a c e . A l a r g e d e t r i t a l i n f l u x from an a d j a c e n t r i v e r system t e r m i n a t e d peat growth. S t a c k e d c r e v a s s e c h a n n e l s a re i n d i c a t e d by f i n i n g - u p w a r d sequences o f s i l t s t o n e s t o mudstones. These sequences have e r o s i o n a l bases t h a t s c o u r e d u n d e r l y i n g d e p o s i t s . C r o s s b e d d i n g and r i p p l e s i n d i c a t e s t r o n g c u r r e n t a c t i v i t y i n the c h a n n e l s . As the c h a n n e l s c l o s e d and the c u r r e n t s waned, f i n e r - g r a i n e d sediments were d e p o s i t e d from s u s p e n s i o n and show e v i d e n c e of d i s t u r b a n c e by p l a n t and an i m a l a c t i v i t y . D i s t a l s p l a y and pond d e p o s i t s were a l s o p r e s e n t i n the form of l a m i n a t e d f i n e - g r a i n e d m a t e r i a l ( F i g u r e 36n). "Fo u r t e e n upper" peat swamp r o o t e d i n the f i n e - g r a i n e d sediments and grew s p o r a d i c a l l y f o r a t l e a s t 40,000 y e a r s ( F i g u r e 36o). I t was i n t e r r u p t e d f r e q u e n t l y by the d e p o s i t i o n o f c l a y p a r t i c l e s from s u s p e n s i o n . The immediate s o u r c e o f t h e s e c l a y p a r t i c l e s may have been ponds t h a t formed above the peat s u r f a c e o r f l o o d waters from an a d j a c e n t r i v e r system. Peat growth was t e r m i n a t e d by a p r o l o n g e d f l o o d i n g event as f l o o d b a s i n sediments were d e p o s i t e d on the p e a t s . C r e v a s s e c h a n n e l s s c o u r e d i n t o u n d e r l y i n g sediments as sands and s i l t s were d e p o s i t e d i n m i g r a t i n g r i p p l e s . The c l o s i n g of c r e v a s s e c h a n n e l s a l l o w e d f i n e r - g r a i n e d s i l t s and muds t o be d e p o s i t e d i n r i p p l e s and p l a n a r l a m i n a t i o n s . D i s t a l s p l a y s and 111 Figure 36 S u c c e s s i v e depos i t iona l envi ronments of Unit III s e d i m e n t s 112 ponding on the f l o o d p l a i n p r o v i d e d f i n e - g r a i n e d sediments f o r "15" peat swamp t o d e v e l o p on ( F i g u r e 36p). F i f t e e n peat swamp was s t a b l e f o r a t l e a s t 55,000 y e a r s and was i n t e r r u p t e d s p o r a d i c a l l y by f l o o d i n g or ponding events t h a t d e p o s i t e d c l a y m i n e r a l s from s u s p e n s i o n on the peat s u r f a c e ( F i g u r e 36q). 2.5. DEPOSITIONAL HISTORY P r i o r t o the d e p o s i t i o n o f the M i s t Mountain s e d i m e n t s , the s t u d y a r e a was p a r t o f a p r o g r a d i n g c o a s t a l complex t h a t was r o u g h l y p a r a l l e l t o the p r e s e n t s t r u c t u r a l t r e n d o f the Rocky Mountains ( G i b s o n , 1977). D u r i n g the L a t e J u r a s s i c ( P o r t l a n d i a n ) the c o a s t a l p l a i n began t o prograde i n t o the F e r n i e B a s i n . T h i s p r o g r a d a t i o n marked the commencement of u p l i f t and e r o s i o n i n the source a r e a t o the southwest and west (Gibson and Highes, 1981; F i g u r e 3 8 ) . The s h a l e s and s i l t s t o n e s o f the upper F e r n i e F o rmation were d e p o s i t e d by t u r b i d i t e and storm a c t i v i t y i n a marine environment (Hamblin and Walker, 1979). Upon s h o r e l i n e p r o g r a d a t i o n , the f i n e - g r a i n e d F e r n i e sediments were o v e r l a i n by the c o a r s e r p r o d e l t a sediments o f the F e r n i e Passage Beds and the beach d e p o s i t s o f the M o r r i s e y F o r m a t i o n . Hamblin and Walker (1979) compared the p r o g r a d i n g c o a r s e n i n g - u p w a r d sequence o f the F e r n i e F o r m a t i o n t o modern r e g r e s s i v e sequences i n wave-dominated d e l t a s o f the Sao F r a n s i s c o and Rhone R i v e r s . In t h e s e d e l t a s , wave a c t i o n i s 1 1 3 F i g u r e 3 6 S u c c e s s i v e d e p o s i t i o n a l e n v i r o n m e n t s o f Un i t III s e d i m e n t s 114 r e s p o n s i b l e f o r r e w o r k i n g and winnowing sediments d e p o s i t e d a t d i s t r i b u t a r y mouths. Longshore c u r r e n t s move c o a r s e r m a t e r i a l a l o n g the c o a s t and d e p o s i t the sand i n i n t e r d i s t r i b u t a r y a r e a s i n beach-dune complexes (Oomkens, 1967; W r i g h t and Coleman, 1973). Sedimentary p a t t e r n s of t h e Weary Ridge and Moose Mountain member sandstones a re c o n s i s t e n t w i t h i n t e r d e l t a i c p r o g r a d i n g s h o r e l i n e c h a r a c t e r i s t i c s . No major d i s t r i b u t a r y c h a n n e l d e p o s i t s o c c u r i n or above the M o r r i s e y sandstone i n the st u d y a r e a . T h i s i m p l i e s t h a t i f the sour c e o f the beach sands was a major d e l t a , i t was l o c a t e d o u t s i d e the st u d y a r e a . Sands of the Weary Ridge member were p r o b a b l y t r a n s p o r t e d t o the a r e a by l o n g s h o r e c u r r e n t s and winnowed by wave a c t i o n t o produce q u a r t z - r i c h sands. In modern e n v i r o n m e n t s , a l i m i t e d t i d a l r a nge, low- t o high-wave energy and a s t a b l e , low g r a d i e n t c o a s t a l p l a i n a r e r e q u i r e d t o form beach d e p o s i t s ( E l l i o t , 1978). Accompanying s h o r e l i n e p r o g r a d a t i o n , wind p l a y e d an i n c r e a s i n g l y i m p o r t a n t r o l e i n s h a p i n g g r a i n s o f a e o l i a n dune sands. W e l l - s o r t e d , w e l l - r o u n d e d q u a r t z a r e n i t e sands of modern beaches, such as the dune complex a t N a y a r i t , Mexico ( C u r r a y e t a l . , 1969), a re analogous t o the a r e n i t e s o f the Moose Mountain Member o f the M o r r i s e y F o r m a t i o n . In many p r e s e n t l y f o r m i n g wave-dominated d e l t a s c o a s t a l p r o g r a d a t i o n l e a d s t o a d e l t a f r o n t - c o a s t a l sand complex t h a t s u p p o r t s r e g i o n a l l y e x t e n s i v e peat swamps ( F l o r e s and E t h r i d g e , 1981). C o n t i n u e d o u t b u i l d i n g and s u b s i d e n c e may l e a d t o peat marshes o f the lower d e l t a p l a i n a d v a n c i n g seaward over the sand 115 Figure 38 Environment of deposi t ion of the Kootenay Group sediments (after G i b s o n and Hughes , 1981) . 116 complex. There i s no e v i d e n c e i n the s t u d y a r e a of l a g o o n a l d e p o s i t s between the M o r r i s e y sandstones and C o a l Seam 1, which s u p p o r t s the c o n c l u s i o n t h a t sediments of U n i t I were d e p o s i t e d on the lower c o a s t a l p l a i n d i r e c t l y b e h i n d the c o a s t a l beach-dune complex. The f a c t t h a t C o a l Seams 1, 2 and 3 are low i n t o t a l s u l f u r c o n t e n t s u p p o r t s the c o n c l u s i o n t h a t t h e r e were no marine or l a g o o n a l i n f l u e n c e s i n the peat swamps of the lower c o a s t a l p l a i n (Home e t a l . , 1978). From ex a m i n i n g the c o a l seam c h a r a c t e r i s t i c s o f U n i t I i t appears t h a t the lower c o a s t a l p l a i n p e a t s were dominated by herbaceous p l a n t s s i m i l a r t o modern sedges, r e e d s , f e r n s and water l i l i e s . The c o a l s of U n i t I are the t h i n n e s t of the t h r e e U n i t s . They average 2 metres i n t h i c k n e s s as compared t o 4 metres i n U n i t I I and 4.6 metres i n U n i t I I I . The U n i t I c o a l seams a l s o c o n t a i n p r o p o r t i o n a t e l y more i n e r t i n i t e and l e s s v i t r i n i t e t han seams of the o t h e r two U n i t s . These two f a c t s s uggest t h a t the peats of the lower c o a s t a l p l a i n c o n t a i n e d l e s s woody m a t e r i a l than peat swamps of the o v e r l y i n g U n i t s . Peats t h a t c o n t a i n e d a d o m i n a n t l y herbaceous component would' p r o v i d e l e s s l i g n i n f o r c o a l seams and would a l s o p r o v i d e l a r g e r s u r f a c e a r e a s f o r o x i d a t i o n than t r e e components (Cohen and Spackman, 1977). L a t e r a l l y the p e a t s o f U n i t I were l i m i t e d by the c h a n n e l s r e s p o n s i b l e f o r the "A" Sandstone and by i n t e r d i s t r i b u t a r y bay s e d i m e n t s . U n i t I sediments are dominated by l a r g e c h a n n e l sandstone b o d i e s t h a t t r e n d n o r t h w e s t - s o u t h e a s t . Two major sandstone b o d i e s make up 40% o f the s t r a t i g r a p h i c sequence and 117 o c c u r i n a s t a c k e d arrangement. T h i n n e r , l e s s e x t e n s i v e sandstones occur m a r g i n a l t o the major b o d i e s . The "A" Lower Channel d e v e l o p e d on and eroded the "2" peat swamp. As the Lower "A" Channel f i l l e d , development o f the "3" peat swamp was l i m i t e d a r e a l l y by the e x t e n t o f c h a n n e l f i l l and v e r t i c a l a c c r e t i o n d e p o s i t s . The abandoned "A" Lower Channel system m a i n t a i n e d a h i g h t o p o g r a p h i c r i d g e which caused a s h i f t o f the Upper "A" Channel i n t o the t o p o g r a p h i c a l l y lower a r e a t o the n o r t h e a s t ( F i g u r e 2 0 e , f ) . The ar e a f o r m e r l y o c c u p i e d by the "A" Lower Channel was t r a n s f o r m e d i n t o a f l o o d p l a i n f o r . t h e overbank and c r e v a s s e sediments o f the "A" Upper Chan n e l . Sediments of U n i t I I accumulated i n a t r a n s i t i o n a l zone between t h e lower and upper c o a s t a l p l a i n s . The d e p o s i t i o n a l environment was a f l u v i a l f l o o d p l a i n - d o m i n a t e d f a c i e s . R i v e r s o c c u r r e d i n meandering b e l t s t h a t t r e n d e d c o n s i s t e n t l y n o r t h e a s t - s o u t h w e s t through the st u d y a r e a . The r i v e r s produced s t a c k e d sandstone b o d i e s t h a t make up 25% of t h i s U n i t . The u n c o h e s i v e , f i n e - g r a i n e d sediments t h a t f l o o r e d the meander b e l t s a l l o w e d the r i v e r s t o m i g r a t e f r e e l y as e v i d e n c e d by the abundant p o i n t bar sequences. The t h i c k c o a l s o f U n i t I I o c c u r o v e r , beneath, l a t e r a l t o and abut t h e s a n d s t o n e s . F o s s i l s found i n U n i t I I i n d i c a t e t h a t p t e r o p s i d s ( f e r n s ) and cycadophytes ( t r e e s w i t h s i m p l e t r u n k s and branches w i t h b l a d e - l i k e l e a v e s ) were common. An i n c r e a s e i n v i t r i n i t e c o n t e n t and average c o a l seam t h i c k n e s s i n U n i t I I as compared t o U n i t I c o a l s i n d i c a t e s an i n c r e a s e i n woody p l a n t m a t e r i a l w i t h r e s p e c t t o herbaceous p l a n t s . T h i s s i t u a t i o n may 118 be analogous t o c o a s t a l p e a t s s t u d i e d i n F l o r i d a by Spackman and o t h e r s (1969) where reed marshland i s i n t e r r u p t e d by the presence o f s m a l l f o r e s t e d i s l a n d s o r hammocks. The p l a n t s w i t h a secondary body produce l a r g e r q u a n t i t i e s of l i g n i n and d e v e l o p p e a t s w i t h a c o a r s e r t e x t u r e than herbaceous p e a t s . C o a l Seams 4L and 4U o c c u r i n the lower p a r t o f U n i t I I t o g e t h e r w i t h f i n e - g r a i n e d f l o o d p l a i n s e d i m e n t s . A major c h a n n e l system developed i n the f l o o d b a s i n and c o e x i s t e d w i t h 5 Seam. S c o u r i n g o f the peats and d e t r i t a l i n p u t from the cha n n e l a r e e v i d e n c e o f t h i s c o e x i s t e n c e . The development of "C" Channel system c l o s e l y f o l l o w e d the t r e n d o f "B" Channe l . I t i s p o s s i b l e t h a t the f l o o d p l a i n - b a c k swamp sediments o u t s i d e o f t h i s meander b e l t were more c o h e s i v e than t h o s e w i t h i n the r i v e r system t h e r e b y l i m i t i n g t he l a t e r a l e x t e n t of meander w i d t h . T h i s i s analogous t o anastamosing r e a c h e s i n modern r i v e r systems where r o o t - s t a b i l i z e d banks i n h i b i t c h a n n e l m i g r a t i o n (Smith and Smith, 1980). No major c o a l seams o c c u r a d j a c e n t t o the "C" Channels. Abandonment o f the "C" Channels l e f t a t o p o g r a p h i c a l l y h i g h a r e a over which the "7" peat swamp s p r e a d . T h i s t o p o g r a p h i c a l l y h i g h a r e a , t r e n d i n g n o r t h e a s t - s o u t h w e s t , i n f l u e n c e d an a u t o -c y c l i c s h i f t o f a s m a l l e r n o r t h w e s t e r n c h a n n e l which c o n t r i b u t e d d e t r i t a l m a t e r i a l t o the a d j a c e n t "7" peat swamp. The peat d i r e c t l y above the submerged "C" Channel r i d g e was the most s t a b l e and, perhaps because i t was t o p o g r a p h i c a l l y h i g h e r , was u n a f f e c t e d by d e t r i t a l i n p u t from a d j a c e n t c h a n n e l s . The "7" peat swamp was i n u n d a t e d by f l o o d b a s i n sediments from 119 c o e x i s t i n g c h a n n e l s . An a r e a l l y l i m i t e d peat swamp ("8"), c o e x i s t e d w i t h f l o o d b a s i n and pond d e p o s i t s and was f r e q u e n t l y d i s t u r b e d by d i s t a l s p l a y s e d i m e n t s . U n i t I I I was d e p o s i t e d i n the upper c o a s t a l p l a i n environment i n a f l o o d p l a i n - d o m i n a t e d f a c i e s . Sandstone b o d i e s are s m a l l and s c a t t e r e d and comprise o n l y 5% o f the U n i t . The m a j o r i t y of t h e sequence a re f l o o d b a s i n d e p o s i t s composed of l a m i n a t e d s i l t s and muds o f overbank and l a k e o r i g i n . The o c c u r r e n c e of v i t r i n i t e - r i c h c o a l s suggest t h a t the swamps were dominated by f o r e s t p e a t s ( T e i c h m u l l e r and T e i c h m u l l e r , 1982). The absence of major c h a n n e l s a l l o w e d t h i c k p e a t s t o d e v e l o p . The peats were c o v e r e d p e r i o d i c a l l y by l a c u s t r i n e sediments c a u s i n g mudstone s p l i t s i n the c o a l s . In some p e a t s , such as those r e s u l t i n g i n 11L, 12 and 14L Seams, c o n t i n u o u s d e t r i t a l i n p u t from f l o o d waters produced a r g i l l a c e o u s c o a l s . Peat d e p o s i t i o n (9 and 11 Seams), a l t e r n a t e d w i t h overbank and pond d e p o s i t i o n u n t i l a s m a l l n o r t h - s o u t h t r e n d i n g c h a n n e l d e v e l o p e d i n the a r e a . The "11U" peat growth was t e r m i n a t e d by the c h a n n e l . Upon ch a n n e l abandonment peat swamp "12" spread a c r o s s the s t u d y a r e a t h i n n i n g above the submerged sandstone r i d g e and c o e x i s t e d w i t h s e v e r a l ponds. The "12" peat swamp was i n t u r n b u r i e d and eroded by the n o r t h w e s t - s o u t h e a s t t r e n d i n g "E" C h a n n e l . Upon abandonment of the "E" Channel, "13" peat swamp spre a d a c r o s s the s t u d y a r e a . Peat d e p o s i t i o n c o n t i n u e d on the upper c o a s t a l p l a i n (14L, 14, 14U), i n t e r s p e r s e d w i t h 120 d e p o s i t s from s m a l l c h a n n e l s , overbank f l o o d i n g and pon d i n g . The "15" peat swamp was s t a b l e f o r a l o n g p e r i o d of time (at l e a s t 54,000 y e a r s ) and marks the end of major peat d e p o s i t i o n on the c o a s t a l p l a i n . III.SEDIMENTOLOGICAL ASPECTS OF COAL OCCURENCES ON EAGLE MOUNTAIN 3.1. INTRODUCTION The p h y s i c a l and c h e m i c a l c h a r a c t e r i s t i c s o f c o a l seams are the r e s u l t of many d i f f e r e n t p a r a m e t e r s . S e v e r a l o f the most i m p o r t a n t c o n t r o l s a re l i s t e d below and d i s c u s s e d i n d e t a i l by J a n s a , 1972; Home e t a l . , 1978; Gi b s o n and Hughes, 1981; K a l k r e u t h , 1982 and S t a c h e t a l . , 1982: 1. d e p o s i t i o n a l environment 2. p e a t - f o r m i n g v e g e t a t i o n t ype 3. c l i m a t e 4. l o c a l t e c t o n i c s i t u a t i o n 5. d i m e n s i o n o f f l o o d b a s i n o r d e l t a The Rocky Mountain Foredeep o f the C r e t a c e o u s was an a r e a t h a t f a v o r e d the growth and p r e s e r v a t i o n o f peat f o r m i n g p l a n t communities, such as the gymnosperms, c o n i f e r s , g i n k o p h y t e s and cycadop h y t e s (Stach e t a l . , 1982). The f o r e d e e p was the s i t e of a molasse d e p o s i t w i t h a temperate t o t r o p i c a l , humid t o wet c l i m a t e (McLean, 1977). T e r r e s t r i a l v a s c u l a r p l a n t f o s s i l s found i n the st u d y a r e a i n c l u d e : C o n i o p t e r i s b r e v i f o l a ( p t e r -121 o p s i d = f e r n ) ; P t i l o p h y l l u m a r c t i c u m , P i t y o p h y l l u m  p h o e n i c o p s i s , Cycadospermum oregonense, P t i l o -p h y l lum (Anonozamites) montanense (cycadophytes) and Pityospermum a n t h r o c i t i c u m ( c o n i f e r ) (Rouse, p e r s comm., 1983). These samples are d e s c r i b e d more f u l l y i n Appendix I . The f o r e d e e p was a d e p o s i t i o n a l s i t e f o r sediments b e i n g shed from r i s i n g mountains i n the s o u t h and west ( F i g u r e 38). Sediments were d e p o s i t e d i n a l l u v i a l p l a i n s , c o a s t a l p l a i n s and d e l t a s . These environments a l s o p r o v i d e d s u f f i c i e n t l a n d , p r o t e c t e d from e r o d i n g f l u v i a l p r o c e s s e s , f o r e x t e n s i v e peat swamps t o d e v e l o p on (McLean, 1977). The p r e s e r v a t i o n of the o r g a n i c m a t e r i a l i n swamps r e q u i r e s a l o n g - t e r m b a l a n c e between the r a t e of a c c u m u l a t i o n and the l o c a l s u b s i d e n c e r a t e ( T e i c h m u l l e r and T e i c h m u l l e r , 1982). In a b a l a n c e d s t a t e , s u b s i d e n c e r a t e s match a c c u m u l a t i o n r a t e s and t h i c k peats are p r e s e r v e d . However, i n a s i t u a t i o n where s u b s i d e n c e r a t e s are l e s s t h a n a c c u m u l a t i o n r a t e s , p e a t s form above the l o c a l water t a b l e and are o x i d i z e d o r eroded. C o n v e r s e l y , g r e a t e r s u b s i d e n c e r a t e s cause a drowning o f the swamps. 3.2. DEPOSITIONAL FACTORS CONTROLLING SEAM PARAMETERS Of p r i m a r y c o n c e r n i n c o a l e x p l o r a t i o n are the d e t e r m i n a -t i o n o f c o a l seam pa r a m e t e r s , such as t h i c k n e s s , l a t e r a l c o n t i n u i t y , a r e a l d i s t r i b u t i o n and q u a l i t y . Numerous s t u d i e s have been done r e l a t i n g c o a l seam c h a r a c t e r i s t i c s t o environment 122 o f d e p o s i t i o n ( W i l l i a m s and K i e t h , 1963; F i s h e r , 1968; Home e t a l . , 1978; F l o r e s , 1980; and o t h e r s ) . These s t u d i e s a l l o w p r e d i c t i v e models t o be a p p l i e d t o c o a l - b e a r i n g sequences d u r i n g e x p l o r a t i o n and mine p l a n n i n g s t a g e s . F l o r e s and E t h r i d g e (1981) p r o v i d e an e x c e l l e n t summary of i n v e s t i g a t i o n s done on T e r t i a r y , C a r b o n i f e r o u s and Upper C r e t a c e o u s c o a l b a s i n s i n the U n i t e d S t a t e s . From t h e s e s t u d i e s s e v e r a l t y p e s of c o a l f o r m i n g environments have been r e c o g n i z e d . Lagoonal o r b a c k - b a r r i e r c o a l s form e l o n g a t e b o d i e s on p l a t f o r m s p a r a l l e l t o e x i s t i n g b a r r i e r systems (Home e t a l . , 1978). Because t i d a l c h a n n e l s may d i s r u p t peat growth the c o a l s a r e t h i n , d i s c o n t i n u o u s and h i g h i n s u l f u r and ash ( F l o r e s and E t h r i d g e , 1981). Modern examples of b r a c k i s h and s a l t water sedge and g r a s s p e a t s are found on the lower d e l t a p l a i n of the F r a s e r R i v e r D e l t a (Styan and B u s t i n , 1983a). The pe a t s a re t h i n , d i s c o n t i n u o u s and c o n t a i n h i g h c o n c e n t r a t i o n s o f t o t a l s u l f u r and ash because o f marine i n c u r s i o n s . C o a l s o f the lower d e l t a p l a i n form on p o o r l y developed l e v e e s t h a t c o n f i n e the s t r a i g h t d i s t r i b u t a r y c h a n n e l s . L a t e r a l l y the peats a re l i m i t e d by e x t e n s i v e d i s t r i b u t a r y b a y - f i l l sequences. C o n s e q u e n t l y , the c o a l s a re t h i n and c o n t i n u o u s p a r a l l e l t o c h a n n e l s (Home e t a l . , 1978). Levee breaches r e s u l t i n c l a y and s i l t c r e v a s s e s p l a y s b e i n g i n t e r c a l a t e d w i t h sedge-grass peats (Styan and B u s t i n , 1983a). Upper d e l t a p l a i n - a l l u v i a l c o a l s form on f l o o d p l a i n s between meandering r i v e r c h a n n e l s and on w e l l d e v e l o p e d l e v e e s . C o a l s a d j a c e n t t o e x i s t i n g c h a n n e l s may d i s p l a y p a r t i n g s o f 123 c r e v a s s e s p l a y o r i g i n and may be eroded by cha n n e l m i g r a t i o n . Styan and B u s t i n (1983a) found peats i n s t a b l e f l o o d p l a i n a r e a s t o be alm o s t c o n s t a n t i n t h i c k n e s s , whereas p e a t s a d j a c e n t t o c h a n n e l s were eroded and i n t e r c a l a t e d w i t h s i l t y - c l a y d e p o s i t s from n a t u r a l l e v e e s . Sedge-grass p e a t s , sedge-wood p e a t s and e r i c a c e o u s Sphagnum peats a re the dominant v a r i e t i e s found i n the upper d e l t a i c - a l l u v i a l environment of the humid, temperate F r a s e r R i v e r D e l t a , whereas i n s u b t r o p i c a l s e t t i n g s such as the M i s s i s s i p p i D e l t a a r b o r a c e o u s v e g e t a t i o n tends t o dominate ( F i s k , 1960; Styan and B u s t i n , 1983a). Home e t a l . (1978) d i s t i n g u i s h a t r a n s i t i o n zone between the lower and upper d e l t a p l a i n s . In t h i s environment the i n t e r d i s t r i b u t a r y bays o f the lower d e l t a p l a i n have been i n f i l l e d c r e a t i n g b r o a d , s t a b l e p l a t f o r m s on which e x t e n s i v e p e a t s can d e v e l o p . The d e t r i t a l i n f l u x from a d j a c e n t c h a n n e l s s t i l l o c c u r s , but presumably the meandering c h a n n e l s o f the upper d e l t a p l a i n have become s t r a i g h t e r i n the t r a n s i t i o n a l environment c r e a t i n g b r o a d e r p e a t - f o r m i n g a r e a s . The d e p o s i t i o n a l environments t h a t p r e c e d e , c o e x i s t w i t h and succeed peat swamps modify the t h i c k n e s s and l a t e r a l e x t e n t of the r e s u l t i n g c o a l . Comparisons o f sandstone c h a n n e l i s o l i t h maps and c o a l i s o p a c h maps demonstrate the r e l a t i o n s h i p between c o e x i s t i n g o r p o s t - d e p o s i t i o n a l environments and c o a l seams of the M i s t Mountain F o r m a t i o n . For example, f i g u r e 37 i l l u s t r a t e s a p a r a l l e l i s m between c o a l and sandstone t h i c k n e s s c o n t o u r s . The t h i c k e s t c o a l s o c c u r i n a r e a s a d j a c e n t t o c h a n n e l s w h i l e t h i n n i n g o r absence o f c o a l s i n c h a n n e l a r e a s i n d i c a t e s e r o s i o n 124 by s c o u r i n g f l u v i a l c u r r e n t s . A l t h o u g h an attempt t o r e l a t e c o a l q u a l i t y (raw ash c o n t e n t ) t o t h e p r o x i m i t y o f sandstone c h a n n e l s f a i l e d t o produce c o n c r e t e r e s u l t s , p a r t i n g s i n the seams are examples o f peat swamp m o d i f i c a t i o n by c h a n n e l s . A s t u d y done on the c o a l - b e a r i n g H a r t s h o r n e F o r m a t i o n of Oklahoma and Arkansas d e t e r m i n e d t h a t c o a l q u a l i t y was a d v e r s e l y a f f e c t e d by the presence o f a d i s t r i b u t a r y c h a n n e l sandstone (Houseknecht and I a n n a c c h i o n e , 1982). In c l o s e p r o x i m i t y t o the sandstone c h a n n e l , the f r e e s w e l l i n g i n d e x o f the c o a l d e c r e a s e d markedly and the s u l f u r c o n t e n t r o s e . A l t h o u g h the e x p l a n a t i o n o f t h e s e t r e n d s i s s p e c u l a t i v e , Houseknecht and I a n n a c c h i o n e (1982) b e l i e v e t h a t ground-water communication between the sandstone and the c o a l bed may have been the main cause. Home e t a l . (1978) d e t e r m i n e d t h a t t h e lower d e l t a p l a i n c o a l s t h a t were o v e r l a i n by b r a c k i s h o r marine r o o f r o c k s c o n t a i n e d h i g h e r amounts of p y r i t i c s u l f u r t h a n c o a l s formed i n t r a n s i t i o n a l and upper d e l t a p l a i n e n v i r o n m e n t s . B u s t i n and S t y a n 1 s r e s u l t s from s t u d y i n g ash and s u l f u r c o n t e n t s i n modern F r a s e r R i v e r D e l t a p e a ts d e t e r m i n e d t h a t the abundance and form of s u l f u r and ash r e f l e c t the pH and d e p o s i t i o n a l s e t t i n g of the p e a t s . In the f o l l o w i n g s e c t i o n s the c o a l seam c h a r a c t e r i s t i c s of the M i s t Mountain F o r m a t i o n are examined and r e l a t e d t o modern peat f o r m i n g e n v i r o n m e n t s . 125 3.3. COAL SEAM CHARACTERISTICS 3.3.1. P r o x i m a t e A n a l y s e s Data S u l f u r Content C o a l s o f the M i s t Mountain F o r m a t i o n a t E a g l e Mountain c o n t a i n minor amounts of s u l f u r (0.3-0.8%). Average p r o x i m a t e a n a l y s i s d a t a f o r the m a j o r i t y of the c o a l seams are p r e s e n t e d i n T a ble 1. A l l d a t a are the r e s u l t of whole seam s a m p l i n g methods. No d e t e r m i n a t i o n o f the p e r c e n t a g e o f o r g a n i c t o p y r i t i c s u l f u r was a v a i l a b l e . There i s no apparent t r e n d o f s u l f u r c o n t e n t i n the s t r a t i g r a p h i c sequence. I r o n d i s u l p h i d e s (FeS 2) o c c u r i n c o a l s i n the m i n e r a l forms p y r i t e and m a r c a s i t e . P r o p o r t i o n a t e l y , p y r i t i c s u l f u r o c c u r s i n minor amounts i n peats when compared t o o r g a n i c s u l f u r . A l t h o u g h minor i n amounts, p y r i t e i s the most v i s i b l e s u l f u r component i n c o a l . P y r i t e and m a r c a s i t e may o c c u r as t u b u l a r r o o t r e p l a c e m e n t s , e u h e d r a l d i s s e m i n a t e d g r a i n s , c l e a t c o v e r i n g s and f r a m b o i d a l masses (Coleman, 1966; Home e t a l . , 1978). In the M i s t Mountain c o a l s p y r i t e o c c u r s as f r a m b o i d a l masses, c l e a t c o v e r i n g s and d i s s e m i n a t e d g r a i n s ( F i g u r e 3 5 ) . P r e r e q u i s i t e s f o r the f o r m a t i o n of p y r i t e and m a r c a s i t e are s u f f i c i e n t s u l f u r and i r o n s u p p l i e s i n the peat environment and f a v o r a b l e pH c o n d i t i o n s . S u l f u r may o r i g i n a t e i n s e v e r a l ways. I t may be a b y p r o d u c t of p l a n t and a n i m a l p r o t e i n o r i t may be brought i n t o the peat swamp by f r e s h o r sea water (Stach e t a l . , 1982). The r e d u c t i o n o f s u l p h a t e f o r p y r i t e f o r m a t i o n may be c a r r i e d out by s u l f u r - r e d u c i n g b a c t e r i a such as D e s u l f o v i b -126 TABLE I - REPRESENTATIVE PROXIMATE ANALYSES • s . Seam R. A. V.M. F.C. I .M. S u l . C.V. 15 15 5 33 61 0.6 0.3 30656 1 14L 7 30 63 0.7 0.7 32918 3 13 14 28 58 0.7 0.7 32720 4 13 25 25 49 0.7 0.7 -1 13 33 21 46 0 . 8 0.5 -4 12 8 22 69 0 . 8 - 31961 11 11U 16 27 57 0.6 0.6 _ 10 11 30 20 44 0.4 0.5 27460 4 11 - 22 69 0.8 0.5 31961 18 11L 27 21 51 0.5 0.6 25560 4 9 - 20 71 0.7 0.5 27637 17 7 29 23 53 0.5 0.7 26273 1 7 8 24 68 0.6 0.6 25779 4 7 15 20 65 0.3 0.4 -5 5 9 21 70 1.4 0.5 31241 1 5L 20 21 60 0.3 0.3 27637 2 4L 18 19 62 0.3 0.3 -5 2 11 22 66 0.6 0.4 31824 12 2 17 21 63 0.4 0.4 -1 1 21 19 59 0.6 1.1 — 1 1 12 23 64 0.6 0.5 29727 # S.= number o f samples (data p r o v i d e d by F o r d i n g Lab.) R.A.= raw ash % V.M.= v o l a t i l e m a t t e r % F.C.= f i x e d carbon % I.M.= i n h e r e n t m o i s t u r e % Sul.= t o t a l s u l f u r % C.V.= c a l o r i f i c v a l u e i n Kj/Kg 127 r i o d e s u l f u r i c a n s i n the presence of a low t o moderate pH (Zobel1,1963; B e r n e r , 1971). From t h e i r s t u d y of modern peats B u s t i n e t a l . (1983a) d e t e r m i n e d t h a t the amount and t y p e of s u l f u r i n d i f f e r e n t p e a ts was a r e f l e c t i o n o f the d e p o s i t i o n a l s e t t i n g , peat f a c i e s and d i a g e n e s i s . Three d e p o s i t i o n a l s e t t i n g s were s t u d i e d i n the F r a s e r R i v e r d e l t a ; lower d e l t a p l a i n , upper d e l t a p l a i n and a l l u v i a l p l a i n . R e s u l t s showed t h a t lower d e l t a p e a t s t h a t were i n f l u e n c e d s o l e l y by marine w a t e r s c o n t a i n e d the h i g h e s t amounts of t o t a l s u l f u r (up t o 6%), and had pH v a l u e s of 5 t o 6. P e a t s i n f l u e n c e d s o l e l y by f r e s h water i n the upper d e l t a and a l l u v i a l p l a i n environments had lower t o t a l s u l f u r c o n t e n t s (<0.5%), and pH v a l u e s of 3.5 t o 4.5. The p e a t s i n the d e l t a t h a t were i n f l u e n c e d by b r a c k i s h water had t o t a l s u l f u r v a l u e s i n t e r m e d i a t e t o those i n f l u e n c e d by marine and f r e s h w a t e r s . The p r i m a r y r e a s o n t h a t p e a t s i n b r a c k i s h - m a r i n e s e t t i n g s have the h i g h e s t t o t a l s u l f u r v a l u e s i s t h a t sea water p r o v i d e s l a r g e amounts of d i s s o l v e d s u l f a t e which can r e a d i l y be c o n v e r t -ed t o E^S by s u l f u r - r e d u c i n g b a c t e r i a . B u s t i n e t a l . ' s (1983a) f i n d i n g s c o r r e l a t e w e l l w i t h the f i n d i n g s o f W i l l i a m s and K i e t h (1963) and Home e t a l . (1978) on the r e l a t i o n s h i p s between h i g h s u l f u r c o a l s and marine r o o f r o c k s . These s t u d i e s d e t e r m i n e d t h a t the type and amount of s u l f u r i n c o a l was more a r e s u l t of t h e d e p o s i t i o n a l s e t t i n g of sediments o v e r l y i n g the c o a l s than of the environments i n which the c o a l s were d e p o s i t e d . B u s t i n e t a l . (1983a), a l s o noted s u l f u r v a r i a t i o n s i n 128 d i f f e r e n t peat f a c i e s . They c o n c e n t r a t e d on comparing t o t a l s u l f u r c o n t e n t s o f f r e s h water Sphagnum p e a t s and sedge-g r a s s marshes. They found t h a t Sphagnum p e a t s had lower t o t a l s u l f u r c o n t e n t s than the sedge-grass peats and c h a r c o a l l a m i n a e . T h i s was a t t r i b u t e d t o s u l f u r a v a i l a b i l i t y i n the p e a t s r a t h e r than t o c h e m i c a l r e a c t i o n s o c c u r r i n g i n t h e . p e a t s . From the minor amounts of s u l f u r c o n t a i n e d i n the M i s t Mountain c o a l s , t h e r e does not appear t o have been a marine i n f l u e n c e d u r i n g d e p o s i t i o n o f the p e a t s . A l t h o u g h U n i t I c o a l s d e v e l o p e d on the lower c o a s t a l p l a i n , no s a l t water or b r a c k i s h water i n f l u e n c e was f e l t by the herbaceous peat swamps. The swamps were p r o t e c t e d from marine i n c u r s i o n s by t h e M o r r i s e y beach-dune complex. The p e a t s must have a c q u i r e d the s u l f u r t h r o u g h the breakdown of o r g a n i c p r o t e i n , from f r e s h water s o u r c e s or from s u l f u r - b e a r i n g m e t e o r i c w a t e r s . The s u l f u r v a r i a t i o n w i t h d e p o s i t i o n a l s e t t i n g and peat f a c i e s found by B u s t i n e t a l . (1983a) i s not seen i n the M i s t Mountain c o a l s . Ash Content Ash c o n t e n t i s low t o moderate i n the M i s t Mountain c o a l s ( 5 - 3 3%). Such a moderate ash c o n t e n t s u g g e s t s an i n - s i t u d e p o s i t i o n (autochthonous) w i t h s l i g h t r e w o r k i n g of the peats ( h y p a u t o c h t h o n o u s ) . F u r t h e r e v i d e n c e s u g g e s t i n g i n - s i t u d e p o s i t i o n i n c l u d e s s e a t e a r t h s , r o o t h o r i z o n s and f o s s i l i z e d t r e e stumps i n growth p o s i t i o n s . The m i n e r a l m a t t e r o c c u r s as e i t h e r i n h e r e n t ash or banded i m p u r i t i e s . I n h e r e n t ash i s s u b m i c r o s c o p i c o r g a n i c matter t h a t cannot be removed from the c o a l by washing. Bands of i m p u r i t i e s i n c o a l t h a t can be 129 r e c o g n i z e d over c o n s i d e r a b l e l a t e r a l d i s t a n c e s are c a l l e d " p a r t i n g s " or " s p l i t s " by m i n e r s . Banded i m p u r i t i e s a re u s u a l l y o f d e t r i t a l o r i g i n , but may be a u t h i g e n i c . The major p o r t i o n o f ash i n peats i s c o n s i d e r e d t o be d e t r i t a l . I s o - a s h maps c o n s t r u c t e d f o r c o a l seams 2-12 demonstrate t h a t h i g h e r ash v a l u e s o c c u r a d j a c e n t t o c h a n n e l and c r e v a s s e f a c i e s ( F i g u r e s 18, 21, 25, 27, 3 7 ) . Co a l p a r t i n g s o c c u r as two main l i t h o l o g i e s ; mudstones and banded i r o n c a r b o n a t e s . The mudstone p a r t i n g s a r e d e t r i t a l whereas the s i d e r i t e s a r e a u t h i g e n i c . X-ray d i f f r a c t i o n a n a l y s i s was c a r r i e d out on mudstone p a r t i n g samples from v a r i o u s p o s i t i o n s i n the M i s t Mountain F o r m a t i o n . R e s u l t s a re d i s c u s s e d i n Appendix I I I . I l l i t e and k a o l i n i t e m i n e r a l s o c c u r i n almost e q u a l amounts. The i l l i t e m i n e r a l s a re i n a degraded s t a t e because o f a t o t a l o r p a r t i a l l o s s o f i n t e r l a y e r p o t a s s i u m i o n s t h r o u g h groundwater l e a c h i n g e i t h e r d u r i n g o r f o l l o w i n g d e p o s i t i o n . The l e a c h i n g p r o c e s s , which i s p r e v a l e n t i n a c i d i c , r e d u c i n g c o n d i t i o n s , removes the s o l u b l e i o n s i n m i n e r a l s and l e a v e s a r e s i d u e of a l u m i n u m - r i c h m i n e r a l s such as k a o l i n i t e (Loughnan, 1969). I l l i t e and k a o l i n i t e a r e w e a t h e r i n g p r o d u c t s of r o c k s i n the d r a i n a g e b a s i n . Staub and Cohen (1979) compared pH v a l u e s i n f r e s h water and b r a c k i s h swamps i n South C a r o l i n a t o determine the mechanics b e h i n d the o c c u r r e n c e o f mud p a r t i n g s . They found t h a t pH v a l u e s were lower i n the f r e s h water swamps (pH<7). T h e i r s t u d y d e t e r m i n e d t h a t d u r i n g f l o o d i n g humic a c i d s caused r a p i d c l a y f l o c c u l a t i o n a t the swamp margins w i t h s m e c t i t e b e i n g 130 c o n v e r t e d t o k a o l i n i t e by the a c i d s . I f mechanisms such as t h i s e x i s t e d d u r i n g the C r e t a c e o u s , the mudstone p a r t i n g s i n the M i s t Mountain c o a l s may have o r i g i n a t e d i n t h i s manner. The s i d e r i t e i n M i s t Mountain c o a l s o c c u r s as d i s t i n c t bands w i t h i n c o a l seams or as n odules or c o n c r e t i o n s a s s o c i a t e d w i t h v a r i e d d e p o s i t i o n a l s e t t i n g s . The s i d e r i t e bands are 3-6 c e n t i m e t r e s t h i c k and can be t r a c e d l a t e r a l l y f o r up t o 100 metres i n the c o a l seams..The s i d e r i t e i s s p h e r u l i t i c , dark b l u e - b l a c k (5 PB 3/2), and has a d u l l l u s t r e . I r o n - c a r b o n a t e c o n c r e t i o n s are most commonly a s s o c i a t e d w i t h f l o o d b a s i n s i l t s t o n e s and s a n d s t o n e s . They o c c u r as s m a l l - t o l a r g e - s c a l e (mm.-m.), w e l l cemented, dense l e n s e s or c o n c r e t i o n s . The con-c r e t i o n s a r e o v a l t o i r r e g u l a r i l y shaped and have a weathered, l i m o n i t e r i m s u r r o u n d i n g a dense, hard c o r e . Under f a v o r a b l e c o n d i t i o n s o f low s u l p h i d e a c t i v i t y , h i g h c a r b o n a t e a c t i v i t y and h i g h F e 2 + / C a 2 + , s i d e r i t e c o n c r e -t i o n s form (Spears and Amin, 1981). These c o n d i t i o n s are e s t a b -l i s h e d e a r l y i n d i a g e n e s i s i n non-marine e n v i r o n m e n t s . I r o n may be p r e s e n t from the s o l u t i o n of o x y h y d r o x i d e m a t e r i a l or c l a y m i n e r a l s (Spears and Amin, 1981) . Carbon d i o x i d e i s produced by a number of c h e m i c a l r e a c t i o n s o c c u r r i n g i n the p l a n t d e b r i s . B a c t e r i a l o x i d a t i o n o f p l a n t d e b r i s and r e d u c t i o n of s u l p h a t e produce CC>2 but the m a j o r i t y of C 0 2 i s produced by the f e r m e n t a t i o n o f o r g a n i c m atter (Matsumoto and I i ' j i m a , 1981). The p r e c i p i t a t i o n of s i d e r i t e i s thus promoted by the i n c r e a s e of Fe a c t i v i t y and the h i g h c o n c e n t r a t i o n o f carbon d i o x i d e . Matsumoto and I i j i m a (1981) s t u d i e d s i d e r i t e o c c u r r e n c e i n 131 Paleogene c o a l seams i n Japan. They p o s t u l a t e d t h a t the c o a l b a s i n s were s u p p l i e d w i t h i r o n o x i d e s , h y d r o x i d e s and k a o l i n c l a y s from s u r r o u n d i n g l a t e r i t i c s o i l s . The c o a l swamps became r i c h i n i r o n when t h e s e suspended c o l l o i d a l p a r t i c l e s e n t e r e d the environment. Reducing c o n d i t i o n s i n the swamp a l l o w e d c o n v e r s i o n o f f e r r i c o x i d e s and h y d r o x i d e s t o s o l u b l e f e r r o u s i o n s (Deans, 1934; C a r r o l l , 1958). T h i s Japanese Paleogene s i t u a t i o n may be analogous t o the M i s t Mountain peat swamps of the C r e t a c e o u s . C l a y p a r t i n g a n a l y s e s suggest i l l i t i c and k a o l i n i t i c s o i l s o c c u r r e d on the s u r r o u n d i n g landmasses. The c l a y m i c e l l e s would p r o v i d e a mechanism f o r t r a n s p o r t i n g i r o n o x i d e s and i r o n h y d r o x i d e s i n t o the peat swamps c r e a t i n g i r o n - r i c h c o n d i t i o n s . X-ray d i f f r a c t i o n , t h i n s e c t i o n and S.E.M. a n a l y s e s a l l o w e d the d e t e r m i n a t i o n o f morphology and c o m p o s i t i o n o f the banded s p h e r u l i t e s i n the M i s t Mountain c o a l s (Appendix I V ) . From t h e s e d a t a i t seems l i k e l y t h a t s i d e r i t e p r e c i p i t a t e d around i r o n o x i d e , i r o n h y d r o x i d e and o r g a n i c n u c l e i i n the peats d u r i n g e a r l y s t a g e s o f d i a g e n e s i s . The l a r g e r s i d e r i t e c o n c r e t i o n s found i n s i l t s t o n e s and sandstones o f t e n cause a d i s r u p t i o n of the b e d d i n g , a t t e s t i n g t o an e a r l y d i a g e n e t i c f o r m a t i o n . T h e i r d i s t r i b u t i o n was l i k e l y c o n t r o l l e d by a heterogeneous i r o n d i s t r i b u t i o n and the l a t e r a l m i g r a t i o n of s t r o n g l y s a t u r a t e d p o r e w a t e r s as found i n Japan (Matsumoto and I i j i m a , 1981). 3.3.2. P e t r o g r a p h i c Data M a c e r a l s are the e l e m e n t a r y , m i c r o s c o p i c c o n s t i t u e n t s of 132 c o a l t h a t can be r e c o g n i z e d by d i s t i n c t i v e p h y s i c a l and c h e m i c a l p r o p e r t i e s . M a c e r a l s can be p r e s e r v e d p l a n t p a r t s or can be the d e g r a d a t i o n p r o d u c t s c r e a t e d i n the c o a l i f i c a t i o n p r o c e s s ( T e i c h m u l l e r and T e i c h m u l l e r , 1982). Table I I p r e s e n t s p e t r o g r a p h i c d a t a f o r s e l e c t e d c o a l seams on E a g l e Mountain. The c h a r t i s s e p a r a t e d i n t o two components; r e a c t i v e and i n e r t m aceral groups. The t h r e e main maceral groups ( v i t r i n i t e , e x i n i t e and i n e r t i n i t e ) , a r e d i f f e r e n t i a t e d based on o r i g i n and morphology. V i t r i n i t e i s d e r i v e d m a i n l y from the l i g n i n s . a n d c e l l u l o s e found i n c e l l w a l l s . I t i s c h a r a c t e r i z e d by a h i g h e r oxygen c o n t e n t than e x i n i t e o r i n e r t i n i t e . The d e r i v a t i o n of e x i n i t e from h y d r o g e n - r i c h p l a n t p a r t s , such as r e s i n s , waxes, spores and p o l l e n s , g i v e s t h i s m a t e r i a l a h i g h a l i p h a t i c ( p a r a f f i n ) f r a c t i o n and a h i g h hydrogen c o n t e n t . A l t h o u g h i n e r t i n i t e i s d e r i v e d from the same p l a n t p a r t s as v i t r i n i t e and e x i n i t e i t undergoes e a r l y c a r b o n i z a t i o n which produces h i g h e r carbon c o n t e n t s and lower hydrogen c o n t e n t s than i n the o t h e r macerals (Stach e t a l . , 1982). T r a n s i t i o n s between v i t r i n i t e and i n e r t i n i t e a r e common ( s e m i - i n e r t i n i t e ) and a r e due t o o x i d a t i o n e f f e c t s d u r i n g peat e x p o s u r e , m o u l d e r i n g and d r y r o t . From the p e t r o g r a p h i c d a t a from E a g l e Mountain (Table I I ) s e v e r a l t r e n d s are apparent.The f i r s t t r e n d i s an i n c r e a s e s t r a t i g r a p h i c a l l y upward of the amount o f v i t r i n i t e . Below 11U c o a l seam, the v i t r i n i t e c o n t e n t i s below 60%. Above t h i s seam, i t f a l l s w i t h i n the range of 60-87%. C o r r e s p o n d i n g l y , the t o t a l i n e r t i n i t e c o n t e n t i s g e n e r a l l y g r e a t e r than 20% below t h i s 133 TABLE I I - COAL PETROGRAPHY DATA R e a c t i v e Components I n e r t Components #s. Seam V. E. S-F. S-F. F. Ro. 15 15 87 7 7 - 2 0 .90 1 14L 61 5 14 - 4 1.05 3 13 70 4 17 — 4 1.07 4 13 45 3 13 - 3 1.03 1 13 81 1 5 9 3 1.05 4 12 54 5 5 10 10 1.12 10 11U 65 2 4 8 13 1.12 1 11U 55 4 23 - 3 1.14 10 11 58 3 5 10 9 1.16 4 11 74 0 4 8 7 1.17 18 11L 51 2 20 — 5 1.21 4 9 44 0 8 16 14 1.25 17 7 49 _ 23 _ 3 1.31 1 7 43 2 33 - 5 1.35 4 7 53 - 6 13 3 1.39 5 5 53 - 8 15 16 1.38 1 5L 42 — 38 — 6 1.37 1 4U 55 — 36 — 4 1.44 2 4L 45 — 26 - 5 1.42 5 2 58 — 34 — 3 1.37 12 2 50 — 34 — 2 1.36 3 1 57 - - - - 1.43 lumber of samples (data p r o v i d e d by F o r d i n g Lab. ) V. = v i t r i n i t e E. = e x i n i t e S-F. = s e m i - f u s i n i t e F. = f u s i n i t e Ro= maximum v i t r i n i t e r e f l e c t a n c e 134 p o s i t i o n and d e c r e a s e s t o v a l u e s of l e s s than 20% above i t . There do not appear t o be any v i s i b l e t r e n d s i n the i n e r t components or i n the e x i n i t e group i n the r e a c t i v e components. Ro max. shows a change a t 11U seam. Below 11U, the Ro v a l u e s o f g r e a t e r than 1.2% i n d i c a t e an A.S.T.M. rank o f medium v o l a t i l e b i t u m i n o u s . Above t h i s p o s i t i o n , the rank d e c r e a s e s t o h i g h v o l a t i l e b i t u m i n o u s , a t v a l u e s of l e s s than 1.2%. T h i s rank i n c r e a s e w i t h depth has been e x p l a i n e d by Hacquebard and Donaldson (1974) as b e i n g a r e s u l t o f i n c r e a s e d t emperature w i t h d e pth ( H i l t 1 s Law) . Cameron (1972) s t u d i e d 39 whole seam samples from Kootenay Group c o a l s t o d e t e r m i n e p a t t e r n s o f maceral component d i s t r i b u t i o n . H i s sample s i t e s i n c l u d e d F o r d i n g Mine and 5 s i t e s w i t h i n 30 k i l o m e t r e s s o u t h o f F o r d i n g . In a l l but one s e c t i o n , the c o a l s i n the lower M i s t Mountain F o r m a t i o n show low v i t r i n i t e and h i g h s e m i - f u s i n i t e c o n t e n t s . The c o a l seams show an i n c r e a s i n g v i t r i n i t e c o n t e n t u p - s e c t i o n . T h i s t r e n d p e r s i s t s f o r a d i s t a n c e of 30 k i l o m e t r e s p a r a l l e l t o the a x i s o f d e p o s i t i o n of the Kootenay c l a s t i c wedge. Cameron d i s t i n g u i s h e d a low v i t r i n i t e zone (<65% v i t r i n i t e ) from a h i g h v i t r i n i t e zone (>65%). The d i v i d i n g l i n e between the zones was found t o be 11 seam a t F o r d i n g Mine. U s i n g J a n s a ' s (1972) i n t e r p r e t a t i o n of the Kootenay d e p o s i t i o n a l environments Cameron suggested t h a t the p e t r o g r a p h i c changes from t h e bottom t o the top o f the s e c t i o n were a r e s u l t o f an e v o l v i n g d e l t a i c system which produced the Kootenay s e d i m e n t s . J a n s a (1972) suggested t h a t c o a l s i n the low v i t r i n i t e zone 135 were formed as open-water lower d e l t a p l a i n p e a t s . T h i s open-water environment would a l l o w water movement which would break down and t r a n s p o r t p l a n t d e b r i s r e s u l t i n g i n a h i g h i n e r t i n i t e , hypautochthonous c o a l (Cameron, 1972). A s h o r e l i n e r e t r e a t t o the e a s t may have caused a s h i f t t o a s h r u b - t r e e dominated peat environment on the upper d e l t a p l a i n . In t h i s environment the v e g e t a t i o n would r e s t r i c t water movement and s t a g n a n t w a t e r s would p r e s e r v e the p e a t s r e s u l t i n g i n the h i g h v i t r i n i t e c o a l s o f the upper s e c t i o n . Cameron's hypotheses on the M i s t Mountain c o a l maceral t r e n d s agree w i t h S tyan and B u s t i n ' s (1983a) f i n d i n g s t h a t b r a c k i s h water peats on the F r a s e r R i v e r lower d e l t a p l a i n c o n t a i n e d m a i n l y v i t r i n i t e and minor i n e r t i n i t e maceral p r e c u r s o r s . Styan (1981) d e t e r m i n e d t h a t i n the F r a s e r d e l t a p e a t s t h e r e i s a n a t u r a l s u c c e s s i o n of peat t y p e s . Sedge-grass p e a t s , such as are found on the lower F r a s e r D e l t a p l a i n , a r e the f i r s t marshes t o form on modern m a r i n e - i n f l u e n c e d d e l t a l o b e s . The sedge-grass components were w e l l p r e s e r v e d as v i t r i n i t e s i n d i c a t i n g a l a c k of exposure. However, as the c l a y - s i l t s u b s t r a t e i s r a i s e d s e v e r a l metres above the marine i n f l u e n c e f r e s h water peat s p e c i e s r e p l a c e the b r a c k i s h water v a r i e t i e s . Exposure and d r y i n g o f p e a t s becomes more f r e q u e n t . T h i s l e a d s t o an i n c r e a s e of the i n e r t i n i t e m a c e r a l s a t the expense o f the v i t r i n i t e m a c e r a l s . At the top of Styan and B u s t i n ' s (1983) s t r a t i g r a p h i c peat sequence i s a predominance o f P i n u s , P i c e a , Populus and B e t u l a . These woody shrubs and t r e e s c o l o n i z e the broad 136 hummocks t h a t were formed by e r i c a c e o u s Sphagnum p e a t s . The a r b o r a c e o u s v e g e t a t i o n c o n t r i b u t e l i g n i n and r e s i n t o v i t r i n i t e -r i c h peats thus p r o v i d i n g minor i n e r t i n i t e and l i p t i n i t e m a c e r a l s . T h i s p r o g r e s s i o n upwards i n the peat sequence from i n e r t i n i t e - r i c h , v i t r i n i t e - p o o r p e a t s t o v i t r i n i t e - r i c h , i n e r t i n i t e - p o o r p e a t s p a r a l l e l s the t r e n d found i n the M i s t Mountain c o a l s which s u g g e s t s an analogous peat s u c c e s s i o n o c c u r r e d i n the C r e t a c e o u s M i s t Mountain p e a t s as i s p r e s e n t l y o c c u r r i n g i n the F r a s e r R i v e r D e l t a . V a s c u l a r p l a n t f o s s i l s found below 11 Upper seam a r e p t e r o p s i d s ( f e r n and seed p l a n t s ) and gymnosperms ( g i n k o , p i n e , f i r , s p r u c e ) . Presumably, i n the t o p o g r a p h i c a l l y l o w e r , w e t t e r a r e a s the f e r n s , r e e d s , sedges and water l i l i e s grew and h i g h e r , d r i e r a r e a s were c o v e r e d by the gymnosperms. T h i s environment i s a c o m b i n a t i o n o f r e e d and f o r e s t moors of T e i c h m u l l e r and T e i c h m u l l e r (1982) and i s s i m i l a r t o modern p e a t - f o r m i n g environments a l o n g the A t l a n t i c and G u l f c o a s t s o f N o r t h America (Spackman e t a l . , 1969; S c h o l l , 1969). Fragments of p t e r o p s i d s would p r o v i d e l a r g e r s u r f a c e a r e a s f o r o x i d a t i o n than t r e e t r u n k s , as w e l l as l e s s l i g n i n . A l l o t h e r f a c t o r s b e i n g e q u a l , low shrubs and g r a s s e s would r e s u l t i n c o a l s w i t h h i g h e r i n e r t i n i t e c o n t e n t s than more mature f o r e s t swamps ( J a n s a , 1972). T h i s f a c t i s s u p p o r t e d by s t u d i e s done on s u b - t r o p i c a l swamps of southwest F l o r i d a by Cohen and Spackman (1977). In e x a m i n i n g t h i n s e c t i o n s from herbaceous and mangrove swamps th e y c o n c l u d e d t h a t the r a t i o o f "framework" ( p l a n t 137 t i s s u e s >100 microns) t o " m a t r i x " ( d e t r i t u s <100 microns) was >1 i n t r e e - d o m i n a t e d p e a t s and was <1 i n herbaceous p e a t s . T h e i r f i n d i n g s s u p p o r t the c o n c l u s i o n t h a t p e a t s t h a t formed below 11U Seam were dominated by herbaceous p l a n t s t h a t produced more d e t r i t a l humic m a t t e r . The e s t a b l i s h m e n t of woody shrubs and t r e e s may have reached a peak above 11U Seam l e a d i n g t o an i n c r e a s e i n l i g n i n and r e s i n components i n the p e a t s . P l a n t f o s s i l s found above 11 Upper Seam were d o m i n a r i t l y gymnosperms. A l t h o u g h o x i d a t i o n , m o u l d e r i n g and c h a r r i n g of the p e a t s i n t o p o g r a p h i c a l l y h i g h e r a r e a s would s t i l l produce i n e r t i n i t e m a c e r a l s , the i n c r e a s e d v i t r i n i t e m a c e rals may be p r o p o r t i o n a t e l y h i g h e r . T h i s peat environment would c o r r e s p o n d t o the f o r e s t moors of T e i c h m u l l e r and T e i c h m u l l e r (1982) . The s u g g e s t i o n t h a t the i n c r e a s e i n v i t r i n i t e c o n t e n t up s e c t i o n may be a r e s u l t o f an i n c r e a s e i n l u s h f o r e s t c o n d i t i o n s i s somewhat c o r r o b o r a t e d by the i n c r e a s e i n average c o a l t h i c k n e s s up s e c t i o n . In U n i t I , the average c o a l t h i c k n e s s i s 2 metres. U n i t I I has c o a l s t h a t range from 2 t o 7.5 metres w i t h an average of 4 metres i n t h i c k n e s s . U n i t I I I , the youngest u n i t , has seams t h a t range from 2 t o 7 metres, w i t h an average t h i c k n e s s o f 4.6 metres. T h i s i n c r e a s e u p s e c t i o n o f o v e r a l l c o a l t h i c k n e s s may be a r e s u l t of p r o g r e s s i v e l y t h i c k e r woody peats c o m p r e s s i n g l e s s than herbaceous p e a t s . A l t e r n a t i v e l y , an e v o l v i n g c o a s t a l p l a i n may have p r o v i d e d a more s t a b l e p e a t - f o r m i n g environment l e a d i n g t o l o n g e r growth p e r i o d s and hence t h i c k e r c o a l seams. 138 3.3.3. Rank C o a l s i n the M i s t Mountain F o r m a t i o n range i n rank from m e d i u m - v o l a t i l e b i t u m i n o u s (maximum v i t r i n i t e r e f l e c t a n c e , Ro max. > 1.21-1.51%), t o h i g h - v o l a t i l e b i t u m i n o u s (Ro max. < 1.21%). The rank i s determined a c c o r d i n g t o p e r c e n t v o l a t i l e m a t t e r and c a l o r i f i c v a l u e . The E a g l e Mountain c o a l s demonstrate a rank change w i t h d e p t h . The seams above 11U Seam are h i g h - v o l a t i l e b i t u m i n o u s . The seams below t h i s p o s i t i o n show an i n c r e a s e i n maximum v i t r i n i t e r e f l e c t a n c e and a change i n rank t o m e d i u m - v o l a t i l e b i t u m i n o u s . An average rank g r a d i e n t can be c a l c u l a t e d from the i n c r e a s e of maximum r e f l e c t a n c e per 100 metres. Pearson and G r i e v e (1980) c a l c u l a t e d an average rank g r a d i e n t of 0.09 Ro/100 metres a t the G r e e n h i l l s open p i t a d j a c e n t t o E a g l e Mountain. Haquebard and Donaldson (1974) s i m i l a r i l y c a l c u l a t e d a g r a d i e n t of 0.092 Ro/100 metres t h r o u g h the i n t e r v a l . 3.4. APPLICATIONS OF DEPOSITIONAL MODEL TO MINING OPERATION The o b j e c t i v e s of t h i s s t u d y were t o determine the environments o f d e p o s i t i o n o f the c o a l - b e a r i n g s t r a t a a t the F o r d i n g Mine and f a c t o r s c o n t r o l l i n g c o a l q u a n t i t y and q u a l i t y . The l o c a l environments were i n t e r p r e t e d from an i n v e s t i g a t i o n of measured s e c t i o n s , c l o s e l y - s p a c e d d r i l l h o l e i n f o r m a t i o n and s t u d i e s done by o t h e r s i n c o a l - r e l a t e d d e p o s i t i o n a l e n v i r o n m e n t s . The r e s u l t s o f t h i s i n v e s t i g a t i o n can be a p p l i e d t o the 139 F o r d i n g m i n i n g o p e r a t i o n i n two major ways. F i r s t , a d e p o s i t i o n a l model can be used i n the i n i t i a l e x p l o r a t i o n phase or i n ongoing e x p l o r a t i o n . A p p l i c a t i o n s i n c l u d e : 1. s i t i n g o f e x p l o r a t i o n d r i l l h o l e s 2. i n i t i a l c o a l seam c o r r e l a t i o n 3. d e f i n i t i o n o f c o a l seam t r e n d s 4. d e f i n i t i o n o f p a l e o c h a n n e l t r e n d s 5. c h a r t i n g o f c o a l q u a l i t y t r e n d s 6. more a c c u r a t e r e s e r v e c a l c u l a t i o n 7. i n i t i a l p i t d e s i g n i n g 8. s i t i n g o f b l a s t i n g d r i l l h o l e s S e c o n d l y , the l o c a l d e p o s i t i o n a l model i s u s e f u l d u r i n g the a c t i v e m i n i n g phase t o a c h i e v e a g r e a t e r e f f i c i e n c y o f c o a l e x t r a c t i o n . In the open p i t o p e r a t i o n a p p l i c a t i o n s i n c l u d e : 1. improved c o a l seam c o r r e l a t i o n 2. improvement i n b l a s t i n g t e c h n i q u e s 3. b e t t e r c o n t r o l of water seepage i n t o p i t s 4. b e t t e r c o n t r o l of h i g h w a l l s t a b i l i t y 5. improved e x t r a c t i o n t e c h n i q u e s Underground m i n i n g a p p l i c a t i o n s i n c l u d e : 1. improved s i t i n g of s h a f t s , s l o p e s and e n t r i e s 2. p r e d i c t i o n of u n s t a b l e r o o f c o n d i t i o n s 3. p r e d i c t i o n of c o a l r o l l s , wants and s p l i t s T h i s s t u d y has shown t h a t s andstone b o d i e s have m o d i f i e d c o a l , seam t h i c k n e s s , l a t e r a l c o n t i n u i t y and q u a l i t y . A p a r a l l e l i s m between sandstone i s o l i t h and c o a l i s o p a c h c o n t o u r s d e f i n e s a r e a s where c h a n n e l l i n g has c r e a t e d c o a l washouts and 140 where c o a l s have t h i n n e d over t o p o g r a p h i c a l l y h i g h e r c h a n n e l s a n d s t o n e s . C o a l q u a l i t y (raw ash c o n t e n t ) i s a d v e r s e l y a f f e c t e d by the c r e v a s s i n g of r i v e r l e v e e s and subsequent d e p o s i t i o n of d e t r i t u s on peat s u r f a c e s . Sandstone p a l e o c h a n n e l s a re r e s p o n s i b l e f o r s e v e r a l more problems e n c o u n t e r e d i n m i n i n g . Channel sandstones u s u a l l y have g r e a t e r p e r m e a b i l i t i e s and c o n d u c t i v i t i e s than s u r r o u n d i n g l i t h o l o g i e s . T h i s makes them perched a q u i f e r s . Water leakage can cause s e v e r a l problems i n open p i t m i n i n g . O x y g e n - r i c h m e t e o r i c w a t e r s promote o x i d a t i o n o f a d j a c e n t c o a l seams t h e r e b y m o d i f y i n g i m p o r t a n t c a l o r i f i c and c o k i n g p r o p e r t i e s ( B u s t i n , 1982). Groundwater seepage tends t o c o l l e c t i n s i l t y - c l a y b a s a l s c o u r s u r f a c e s and may p r e s e n t d r i l l i n g and b l a s t i n g problems. P r e d i c t i o n of s a t u r a t e d a r e a s t h r o u g h d e p o s i t i o n a l m o d e l l i n g can a l l e v i a t e problems by a l l o w i n g e n g i n e e r s t o a l t e r d r i l l i n g p a t t e r n s t o compensate f o r i n c r e a s e d groundwater e f f e c t s . An a n a l y s i s o f l i t h o l o g i c t r e n d s would a l s o d e l i n e a t e the more competent u n i t s a s s o c i a t e d w i t h c h a n n e l l i n g and the l e s s competent, t h i n n e r f l o o d bas.in d e p o s i t s t h a t o c c u r a d j a c e n t t o c h a n n e l s . A d e t a i l e d u n d e r s t a n d i n g o f the l o c a l d e p o s i t i o n a l system would a i d i n the o p t i m i z a t i o n o f overburden b l a s t i n g p r o c e d u r e s such as l o c a t i o n and type of d r i l l h o l e s p a c i n g and type and amount o f charge. P i t d e s i g n can a l s o b e n e f i t from an u n d e r s t a n d i n g o f the l o c a l d e p o s i t i o n a l s i t u a t i o n . P i t h i g h w a l l s t h a t a re o r i e n t e d p e r p e n d i c u l a r t o major p a l e o c h a n n e l s w i l l be more s t a b l e than t h o s e o r i e n t e d p a r a l l e l t o the p a l e o c h a n n e l edge (Massoth, 141 1982). The c h a n n e l edge-levee i s an a r e a of r a p i d f a c i e s changes. D i f f e r e n t i a l c o m p a c t i o n , s l i c k e n s i d e s and water seepage a s s o c i a t e d w i t h t h e s e f a c i e s changes may cause h i g h w a l l f a i l u r e s . C o a l r o l l s , c o a l wants and s p l i t s are en c o u n t e r e d i n b o t h open p i t and underground m i n i n g o p e r a t i o n s . C o a l r e s e r v e s can be s u b s t a n t i a l l y reduced where c h a n n e l l i n g has sco u r e d i n t o c o a l seams and where d e t r i t u s from c h a n n e l f l o o d i n g has d i s r u p t e d peat growth. C o a l r o l l s a r e a r e s u l t of d i f f e r e n t i a l compaction beneath sandstone c h a n n e l s . L o c a l l y , the v a r y i n g d i p s o f the c o a l r o l l s can g r e a t l y h i n d e r the movement o f haulage and mi n i n g equipment (Houseknecht and I a n n a c c h i o n e , 1982). A l t h o u g h no underground m i n i n g i s o c c u r r i n g p r e s e n t l y a t F o r d i n g , any f u t u r e o p e r a t i o n s h o u l d t a k e i n t o c o n s i d e r a t i o n the u n s t a b l e r o o f and f l o o r c o n d i t i o n s a s s o c i a t e d w i t h p a l e o -c h a n n e l s . J o i n t e d and s l i c k e n s i d e d s u r f a c e s o c c u r f r e q u e n t l y i n the channel s a n d s t o n e s . S l i c k e n s i d e s can r e s u l t from the d i f f e r e n t i a l c ompaction o f sandstones and c l a y s t o n e s . They o c c u r on c o n t a c t s between c r o s s b e d s e t s . The i n t e r s e c t i o n of j o i n t s e t s and s l i c k e n s i d e s may cause u n s t a b l e r o o f c o n d i t o n s . Sedimentary f a c i e s mapping completed d u r i n g the e a r l y e x p l o r a t i o n phase may be used t o e v a l u a t e the q u a n t i t y and q u a l i t y o f a v a i l a b l e r e s e r v e s . C ontinuous u p d a t i n g of f a c i e s maps d u r i n g the a c t i v e m i n i n g stage can i n c r e a s e the e f f i c i e n c y o f c o a l e x t r a c t i o n . 142 SUMMARY AND CONCLUSIONS The L a t e J u r a s s i c - E a r l y C r e t a c e o u s M i s t Mountain F o r m a t i o n a t E a g l e Mountain i s a 550 metre t h i c k i n t e r v a l o f non-marine c l a s t i c sediments t h a t were d e p o s i t e d i n the Rocky Mountain Foredeep. S e d i m e n t o l o g i c a l s t u d i e s were c a r r i e d out u s i n g o u t c r o p and s u b s u r f a c e d a t a i n an e f f o r t t o : 1. D e f i n e major c l a s t i c l i t h o f a c i e s i n the M i s t Mountain F o r m a t i o n ; 2. Determine l i t h o f a c i e s a s s o c i a t i o n s u s i n g d e t a i l e d s e d i m e n t o l o g y ; 3. Develop d e p o s i t i o n a l models f o r the major c l a s t i c u n i t s and; 4. R e l a t e c o a l seam parameters ( l a t e r a l c o n t i n u i t y , t h i c k n e s s and c o a l q u a l i t y ) t o d e p o s i t i o n a l s e t t i n g . The M i s t Mountain F o r m a t i o n was d i v i d e d i n t o t h r e e major l i t h o f a c i e s , U n i t s I , I I and I I I . These u n i t s a re based on d i s t i n c t i v e sandstone body geometry and c o a l seam c h a r a c t e r -i s t i c s . The sediments o f the t h r e e u n i t s are i n t e r p r e t e d as f o r m i n g i n f l u v i a l c h a n n e l s , c r e v a s s e c h a n n e l s and s p l a y s , l e v e e s and f l o o d b a s i n s . These f a c i e s a re r e p r e s e n t e d by d i s t i n c t d e p o s i t s : 1. Channel d e p o s i t s - make up 15% o f F o r m a t i o n . They are 5-20 metre t h i c k t a b u l a r - l e n t i c u l a r b o d i e s . The channel sandstones a re f i n e - t o c o a r s e - g r a i n e d immature l i t h a r e n i t e s t h a t weather l i g h t - t o d a r k - g r e y (N7-N4), b u f f (10 YR 8/2), o r r u s t (10 YR 6/6). B a s a l l a g 143 d e p o s i t s and medium- t o l a r g e - s c a l e p l a n a r and t r o u g h c r o s s - s t r a t i f i c a t i o n c h a r a c t e r i z e the lower c h a n n e l s a n d s t o n e s . Upper sandstones are f i n e r - g r a i n e d and c h a r a c t e r i z e d by s m a l l - t o medium-scale p l a n a r and r i p p l e c r o s s - l a m i n a t i o n s . 2. C r e v a s s e c h a n n e l d e p o s i t s - a ) , p r o x i m a l s p l a y s are composed of f i n e - g r a i n e d s a n d s t o n e s , s i l t s t o n e s and mudstones t h a t f i n e - u p w a r d s i n 3-5 metre s e t s . Sandstones weather b r o w n i s h - g r e y (5 YR 4/1) t o d a r k - g r e y (N3) or are r u s t y c o l o r e d (10 YR 6/6). B a s a l l a g d e p o s i t s are o v e r l a i n by s m a l l - t o l a r g e - s c a l e p l a n a r and r i p p l e c r o s s - s t r a t i f i c a t i o n . The lower sandstones grade i n t o s i l t s t o n e s t h a t show c l i m b i n g r i p p l e s , p l a n a r l a m i n a t i o n s and s o f t - s e d i m e n t d e f o r m a t i o n s t r u c t u r e s . b ) . d i s t a l s p l a y d e p o s i t s commonly coarsen-upward and are composed of i n t e r b e d d e d sandstone and s i l t s t o n e w i t h minor mudstone. S t a c k e d sequences are 1-3 metres i n t h i c k n e s s . The sandstones are v e r y f i n e - g r a i n e d and both sandstones and s i l t s t o n e s weather b r o w n i s h - g r e y (5 YR 4/1) . 3. Levee d e p o s i t s - are a minor component of the F o r m a t i o n but a r e r e c o g n i z e d by t h e i r p r o x i m i t y t o c h a n n e l d e p o s i t s . The i n t e r b e d d e d sandstones and s i l t s t o n e s weather b r o w n i s h - g r e y (5 YR 4/1) t o d a r k - g r e y (N3) and f i n e upward t o r o o t e d mudstone and c o a l . S m a l l - s c a l e p l a n a r and r i p p l e , l a m i n a t i o n s are the most common se d i m e n t a r y s t r u c t u r e s . 144 4. F l o o d b a s i n d e p o s i t s - t h r e e t y p e s o c c u r : overbank sheet f l o w d e p o s i t s , swamp d e p o s i t s and pond d e p o s i t s . a) . overbank d e p o s i t s a r e composed of i n t e r b e d d e d s i l t s t o n e s and mudstones t h a t weather l i g h t - t o medium-grey (N5-N7). P l a n a r l a m i n a t i o n s and s o f t -sediment d e f o r m a t i o n s t r u c t u r e s are the commonest se d i m e n t a r y f e a t u r e s . b) . swamp d e p o s i t s a re r e p r e s e n t e d by c o a l seams. The seams v a r y i n t h i c k n e s s , l a t e r a l c o n t i n u i t y and ash c h a r a c t e r i s t i c s because of a d j a c e n t d e p o s i t i o n a l e n v i r o n m e n t s . c) . pond d e p o s i t s a r e r e p r e s e n t e d by l a m i n a t e d o r g a n i c mudstones and s i l t s t o n e s t h a t weather brown (5 YR 4/1) or dark g r e y (N3). Pond d e p o s i t s are a s s o c i a t e d w i t h swamp d e p o s i t s and c o n t a i n abundant p l a n t f o s s i l s . The sediments of U n i t I were d e p o s i t e d on a c o a s t a l p l a i n i m m e d i a t e l y b e h i n d an i n t e r d i s t r i b u t a r y beach-dune complex ( M o r r i s e y F o r m a t i o n s a n d s t o n e s ) . F r e s h water herbaceous peats (Coal Seams 1, 2 and 3) developed on hummocky p l a t f o r m s between the s t r a i g h t d i s t r i b u t a r y c h a n n e l s r e s p o n s i b l e f o r the "A" Sandstones. The n o r t h w e s t - s o u t h e a s t c h a n n e l s l i m i t e d the l a t e r a l e x t e n t of the peat swamps and i n t r o d u c e d d e t r i t u s onto peat s u r f a c e s t h r o u g h c r e v a s s e and overbank f l o o d i n g . The lower c o a s t a l p l a i n was dominated by the "A" Channels and t h e i r a s s o c i a t e d c r e v a s s e - o v e r b a n k s e d i m e n t s . As the c o a s t a l p l a i n prograded i n t o the F e r n i e Sea, the st u d y a r e a e v o l v e d from a lower c o a s t a l p l a i n environment t o a 145 t r a n s i t i o n a l zone between the lower and upper c o a s t a l p l a i n s . U n i t I I sediments were d e p o s i t e d i n t h i s t r a n s i t i o n a l zone i n a f l u v i a l f l o o d p l a i n - d o m i n a t e d f a c i e s where meandering r i v e r s t r e n d e d n o r t h e a s t - s o u t h w e s t . Dominant herbaceous p e a t s and minor f o r e s t swamps (Coal Seams 4, 5, 7 and 8) d e v e l o p e d i n f l o o d p l a i n a r e a s a d j a c e n t t o r i v e r s . Channel m i g r a t i o n l e d t o p a r t i a l o r t o t a l e r o s i o n o f some peats and c r e a t e d muddy i n t e r b e d s i n o t h e r p e a t s . Sediments o f U n i t I I I were d e p o s i t e d i n a f l o o d p l a i n - d o m i n a t e d f a c i e s of the upper c o a s t a l p l a i n . Channel f a c i e s make up o n l y 5% of t h i s U n i t . The m a j o r i t y of the sediments are o f overbank and swamp o r i g i n . Gymnosperm-cycadophyte swamps were more deve l o p e d than those of U n i t s I and I I because o f d e c r e a s e d c h a n n e l a c t i v i t y . C o a l seams o c c u r i n a l l t h r e e U n i t s o f the F o r m a t i o n . The c h a r a c t e r i s t i c s o f the seams are a r e f l e c t i o n o f the environments i n which the peat swamps formed. T h i c k n e s s , l a t e r a l c o n t i n u i t y and q u a l i t y o f the seams are a d v e r s e l y a f f e c t e d by p a l e o c h a n n e l geometry. E r o s i o n o f peats by a c t i v e r i v e r c h a n n e l s has c r e a t e d washouts. T h i n n e r c o a l seams r e f l e c t peat t h i n n i n g over t o p o g r a p h i c a l l y h i g h e r c h a n n e l p r e c u r s o r s . Number of s i l t s t o n e and mudstone p a r t i n g s and raw ash c o n t e n t s o f the seams i n c r e a s e markedly as p a l e o c h a n n e l s are approached. The c l e a n e s t c o a l s are found i n f l o o d b a s i n a r e a s removed from the f l u v i a l i n f l u e n c e . C o a l seams i n the lower M i s t Mountain F o r m a t i o n are low i n the maceral v i t r i n i t e and h i g h i n i n e r t i n i t e . T h i s r e f l e c t s the 146 dominant herbaceous peat c o m p o s i t i o n and the h i g h e r degree of d e c o m p o s i t i o n of p e a t s on the lower and t r a n s i t i o n a l c o a s t a l p l a i n s . C o a l s o f the upper c o a s t a l p l a i n a re r i c h i n v i t r i n i t e and low i n i n e r t i n i t e r e f l e c t i n g a s h i f t i n dominant peat t y p e s t o woody shrubs and t r e e s . 147 APPENDIX I - P a l e o n t o l o g y Summary Seven samples were c o l l e c t e d from o u t c r o p and d r i l l c o r e f o r p a l e o n t o l o g i c a l a n a l y s e s . V i s i b l e f o s s i l s were p r e s e n t i n sa n d s t o n e s , s i l t s t o n e s and s h a l e s . The samples were s u b m i t t e d t o Dr. G. Rouse f o r i d e n t i f i c a t i o n . The r e s u l t s a r e p r e s e n t e d i n t a b u l a r form below. Sample # L o c a t i o n F o s s i 1 1 F e r n i e Fm. D.D.H. 1757 B u c h i a C o n c e n t r i c a 2 4-5 seam i n t e r v a l D.D.H. 1628 P i t y o p h y l l u m p h o e n i c o p s i s P t i l o p h y l l u m a r c t i c u m 3 4-5 seam i n t e r v a l D.D.H. 1628 Cycadospermum oregonense 4 below 9L seam D.D.H. 1757 C o n i o p t e r i s b r e v i f o l i a 5 below 9 seam D.D.H. 1752 Pityospermum c f . a n t h r o -c i t i c u m 6 above 14L seam D.D.H. 1757 P t i l o p h y l l u m (anonoza-mites) montanense 7 below 15 seam Podozamites l a n c e o l a t u s The o l d e s t f o s s i l , number 1, i s an a s s y m e t r i c a l p e l e c y p o d t h a t i s c h a r a c t e r i s t i c of marine s t r a t a . The r e m a i n i n g f o s s i l s r e p r e s e n t t e r r e s t r i a l v a s c u l a r p l a n t s . Samples 2, 4, and 6 are examples o f p t e r o p s i d l e a v e s , which a re s i m i l a r t o modern f e r n s . Samples 3 and 7 are examples o f cycadophytes or gymnosperms. Cycadophytes a r e s i m i l a r t o modern palm t r e e s i n t h a t they had a 148 s i m p l e t r u n k and branches w i t h b l a d e - l i k e l e a v e s ( N e l s o n , 1970) . Sample 5 i s a member of the c o n i f e r s . As w i t h p r e s e n t p i n e s and f i r s , the l e a v e s are n e e d l e - l i k e and the seeds are e n c l o s e d i n cones ( N e l s o n , 1970). 149 APPENDIX I I - T h i n S e c t i o n A n a l y s e s E i g h t l i t h o l o g i e s were sampled t o determine the m i n e r a l o g y o f r e p r e s e n t a t i v e r o c k t y p e s . The r o c k s were t h i n s e c t i o n e d and a n a l y z e d s e m i - q u a n t i t a t i v e l y u s i n g a p e t r o g r a p h i c m i c r o s c o p e . An attempt was made t o i d e n t i f y and q u a n t i f y framework and m a t r i x g r a i n s and cement t y p e s . The r e s u l t s a r e p r e s e n t e d i n t a b u l a r form below. Sample l o c a t i o n L i t h o l o g y Framework M a t r i x Cement 0.5-1.Omm 0.1-0.5mm B a s a l Sandstone s u b l i t h - q u a r t z 60% p y r i t e 2% i r o n 5% a r e n i t e c h e r t 15 mu s c o v i t e 1 c a r b o n a t e l i t h i c z i r c o n T f r a g s . 15 c h l o r i t e T 4 Seam f o o t w a l l mudstone q u a r t z + a p a t i t e 3% i r o n c h e r t 40% i r o n 25 b i o t i t e 2 o r g a n i c s 30 4 Seam p a r t i n g mudstone q u a r t z 2% c l a y s 78% h e m a t i t e c h e r t 3 p y r i t e c l a y s 12 o r g a n i c s 5 above 4 Seam l i t h a r e n i t e q u a r t z 40% q u a r t z 10% s i l i c a c h e r t 15 c l a y s 5 o r g a n i c s 5 i r o n 1-2 c a l c i t e 5 c l a y 5 a p a t i t e 1-2 c h e r t 10 ca r b o n a t e c a l c i t e 1-2 o r g a n i c s 1-2 150 Sample L o c a t i o n L i t h o l o g y Framework M a t r i x Cement 0.5-1.Omm 0.1-0.5mm below 7 Seam l i t h a r e n i t e c h e r t 15% q u a r t z 15 c l a y 10 v o l c a n i c f r a g s . 10 c a l c i t e 5 opaques 10 c a l c i t e 5% s i l i c a 6% musc o v i t e 4 opaques 5 c h e r t 10 o p a l 5 above 4 Seam s i l t s t o n e q u a r t z 65% c a l c i t e 3% c a l c i t e 15 o r g a n i c s 2 opaques 15 above 4 Seam s h a l e q u a r t z 10% c l a y 60 o r g a n i c s 25 micas 5 between 3 and 4 Seams s i l t s t o n e c l a y s 20% q u a r t z 20 c a l c i t e 20 i r o n 10 c h e r t 5 c a l c i t e 25% 151 APPENDIX I I I - C l a y M i n e r a l o g y Sample P r e p a r a t i o n E l e v e n samples were s e l e c t e d from s h a l e s and mudstones f o r c l a y m i n e r a l a n a l y s e s . The samples were chosen a t v a r i a b l e i n t e r v a l s t o determine i f any s t r a t i g r a p h i c v a r i a t i o n o f c l a y m i n e r a l s e x i s t e d . Samples were p u l v e r i z e d t o c l a y - s i z e d p a r t i c l e s u s i n g a hammer, s i e v e and r i n g g r i n d e r . The equipment was c l e a n e d w i t h compressed a i r between samples t o reduce the chance o f c o n t a m i n a t i o n . The samples were then s l a k e d i n one l i t r e of d e - i o n i z e d water by s e d i m e n t a t i o n f o r e i g h t h o u r s . I t was n e c e s s a r y t o skim o f f h y d r o p h o b i c carbonaceous p a r t i c l e s from s e v e r a l samples. Two samples proved t o be more c o a l than c l a y and were d i s c a r d e d . A -2 micrometre f r a c t i o n was s e p a r a t e d and a l l o w e d t o s e t t l e by s e d i m e n t a t i o n . One m i l l i m e t r e o f -2 micrometre s o l u t i o n was p i p e t t e d onto a c l e a n g l a s s s l i d e and a l l o w e d t o s e t t l e and d r y a t room temperature t o produce an o r i e n t e d s l i d e . A f t e r i n i t i a l X-ray d i f f r a c t i o n the n i n e o r i e n t e d c l a y s l i d e s were g l y c o l a t e d i n a d e s s i c a t o r f o r one day a t room t e m p e r a t u r e . The s l i d e s were s u b j e c t e d t o X-ray d i f f r a c t i o n a g a i n . An X-ray d i f f r a c t o m e t e r was used w i t h CuK a l p h a r a d i a t i o n and a N i f i l t e r . The o r i e n t e d s l i d e s were scanned between 3 and 13 degrees 2 t h e t a a t 1 degree 2 t h e t a / m i n u t e w i t h a 2 second time c o n s t a n t . 152 D i s c u s s i o n Of R e s u l t s The two main c l a y m i n e r a l s a re i l l i t e and k a o l i n i t e , w i t h i l l i t e o c c u r r i n g i n s l i g h t l y l a r g e r q u a n t i t i e s . In the f i r s t r un the 001 k a o l i n i t e r e f l e c t i o n was a d i s t i n c t , c l e a n s y m m e t r i c a l peak t h a t o c c u r r e d between 7.08 and 7.31 Angstroms. A f t e r g l y c o l a t i o n the peak was a g a i n s y m m e t r i c a l but was s l i g h t l y expanded from 7.08 t o 7.38 Angstroms. The 001 i l l i t e r e f l e c t i o n i s an i n d i s t i n c t expanded peak w i t h v a l u e s r a n g i n g from 9.38 t o 11.19 Angstroms i n the f i r s t r u n . A f t e r g l y c o l a t i o n t h e r e appears t o be a minimal d e c r e a s e i n the l a t t i c e s p a c i n g below c o a l seam 9 and a s l i g h t e x p a n s i o n above 9 seam. T h i s i s shown d i a g r a m m a t i c a l l y i n f i g u r e 39. N o r m a l l y , the i l l i t e u n i t l a y e r has a t h i c k n e s s of a p p r o x i m a t e l y 10 Angstroms and appears as a c l e a n , d i s t i n c t peak on the X-ray t r a c e . However, as i s the case w i t h the M i s t Mountain i l l i t e s , when a p a r t i a l or t o t a l amount of i n t e r l a y e r K + i o n s a r e l o s t from the s t r u c t u r e , d e g r a d a t i o n o c c u r s and the s t r u c t u r e has a tendency t o expand when water i s p r e s e n t (Loughnan, 1969). In t h i s degraded form i l l i t e o f t e n l o s e s one of i t s t e t r a h e d r a l s i l i c a s h e e t s and i s c o n v e r t e d t o k a o l i n i t e . T h e r e f o r e , p a r t of the k a o l i n i t e p r e s e n t i n the mudstones examined may be a r e s u l t o f i l l i t e d e g r a d a t i o n . K a o l i n i t e and i l l i t e a r e both abundant i n c o n t i n e n t a l f l u v i a t i l e environments and are i n d i c a t i v e o f the l e a c h i n g o f s o i l and r o c k h o r i z o n s i n swamp and f l o o d p l a i n a r e a s . In these e n v i r o n m e n t s , s a t u r a t i o n o f the near s u r f a c e a r e a may oc c u r as a r e s u l t of a s h a l l o w water t a b l e . A c i d i c , r e d u c i n g c o n d i t i o n s 153 S E A M S 1 5 | 1 4 U -1 4 -1 3 1 2 1 1 U 11 H 9 8 H 500-1 4 5 0 H 4 0 0 J 3 5 0 H 3 0 0 4 2 5 0 4 2 0 0 4 150H 100 H 50-^ 2 1 H CO CO CO E x" t— o_ UJ Q A i r d r y e d G l y c o l a t e d H i O < LU H - I — i 1 1 1 1 1 1 1 1 1 10 2 0 3 0 4 0 50 60 70 80 9 0 100 % C l a y Figure 3 9 C l a y mineral p e r c e n t a g e s in mudstone part ings 154 o f t e n p r e v a i l i n swampy areas and enhance the l e a c h i n g p r o c e s s . T h i s p r o c e s s removes the s o l u b l e p o r t i o n o f m i n e r a l s and l e a v e s b e h i n d r e s i d u a l m i n e r a l s r i c h i n aluminum, such as the k a o l i n group of c l a y m i n e r a l s (Loughnan, 1969). I f p r e s e n t day s o i l c l a s s i f i c a t i o n s a r e a p p l i e d t o these c l a y types i t may be p o s t u l a t e d t h a t the r e s u l t i n g mudstone h o r i z o n s formed i n one of t h r e e s o i l h o r i z o n s : 1. Red-brown e a r t h s a re p r e s e n t l y c h a r a c t e r i s t i c of the lower l a t i t u d e s w i t h r a i n f a l l s of 30.5-63.5 m i l l i m e t r e s per y e a r and are formed from o x i d i z e d o r g a n i c s ; 2. P o d s o l s a re l e a c h e d s o i l s o c c u r r i n g i n c o o l , humid s u b t r o p i c a l f o r e s t s w i t h moderate t o h i g h r a i n f a l l and unimpeded d r a i n a g e ; 3. Hydromorphic s o i l s a r e c h a r a c t e r i s t i c of p o o r l y d r a i n e d swamps where the water t a b l e i s s h a l l o w and the peat i s s a t u r a t e d . A l l of the s e s o i l t y p e s a re p r e s e n t l y b e i n g produced and are r i c h i n i l l i t e and k a o l i n i t e c l a y m i n e r a l s . 155 APPENDIX IV - C o a l P a r t i n g A n a l y s e s S p h e r u l i t i c p a r t i n g s are a s s o c i a t e d w i t h c o a l seams i n the M i s t Mountain F o r m a t i o n . The p a r t i n g s o ccur as 3-5 c e n t i m e t r e dense bands t h a t weather t o a b l u i s h c o l o r . Brown i r o n s t a i n i n g o c c u r s on some weathered s u r f a c e s . The c o n t a c t s w i t h the o v e r l y i n g and u n d e r l y i n g c o a l s a re a b r u p t and c o n f o r m a b l e . The p a r t i n g s can be t r a c e d f o r one hundred metres i n o u t c r o p . They ar e apparent i n o u t c r o p because of the d i f f e r e n c e i n l u s t r e between the v i t r e o u s c o a l and the d u l l p a r t i n g . P r o c e d ures For Sample P r e p a r a t i o n E i g h t c h i p samples were s e n t t o L o r i n g L a b o r a t o r i e s L t d . f o r phosphorous a s s a y s . F i v e o f t h e s e samples were c o a l seams and t h r e e were p a r t i n g s c o n t a i n e d i n the seams. The r e s u l t s a re shown i n t a b u l a r form below. Of the e i g h t c h i p samples, the t h r e e p a r t i n g s were p r e p a r e d f o r X-ray d i f f r a c t i o n a n a l y s i s . A one gram sample was p u l v e r i z e d u s i n g a r i n g - g r i n d e r t o produce a v e r y f i n e - g r a i n e d sample. The samples were then s l a k e d i n d e - i o n i z e d water and i n t e r m i t t e n t l y s t i r r e d t o l i b e r a t e carbonaceous m a t e r i a l which was then skimmed o f f . The water was then siphoned o f f and the r e s u l t i n g s l u r r y poured onto a g l a s s s l i d e (2.5 x 4 cms). The s l i d e was washed w i t h acetone u n t i l a v e r y t h i n l a y e r c o v e r e d the s l i d e . T h i s was then a i r d r i e d and one t h i r d o f the s l i d e was c l e a n e d o f f f o r placement i n the d i f f r a c t o m e t e r . An X-ray d i f f r a c t o m e t e r was used on two o c c a s i o n s . On the 156 f i r s t o c c a s i o n CuK a l p h a r a d i a t i o n w i t h a N i f i l t e r were used. The m a t e r i a l was scanned between 4 and 35 degrees 2 t h e t a a t 1 degree 2 t h e t a / m i n u t e or 2 degrees 2 t h e t a / m i n u t e w i t h a time c o n s t a n t of 2. An e x t r e m e l y h i g h background o c c u r r e d when u s i n g the Cu r a d i a t i o n so a second r u n n i n g o f the samples was c a r r i e d out w i t h an Fe r a d i a t i o n and an Mn f i l t e r . The m a t e r i a l was scanned from 3 t o 60 degrees a t a speed of 2 degrees 2 t h e t a / minute w i t h a time c o n s t a n t of 2. The background was s i g n i f i c a n t l y l o w e r e d. A c l e a n , s y m m e t r i c a l peak o c c u r r i n g a t 31.65 was det e r m i n e d t o be s i d e r i t e i n a l l the samples. Seven c o a l p a r t i n g samples were s e l e c t e d f o r a n a l y s e s by Scanning E l e c t r o n M i c r o s c o p e . The samples were s e l e c t e d on the b a s i s o f hand specimen e x a m i n a t i o n , X-ray d i f f r a c t i o n r e s u l t s and t h i n s e c t i o n p e t r o l o g y . T h i n s e c t i o n s were c a r b o n - c o a t e d and examined u s i n g S.E.M. and b a c k s c a t t e r i n g element d i s t r i b u t i o n a n a l y s e s maps. RESULTS Phosphorous A n a l y s e s Sample # L o c a t i o n 5 4 Seam p a r t i n g 1.85 7 4 Seam p a r t i n g 0.28 45 12 Seam c o a l 0.10 48 9 Seam c o a l 1.67 49 9 Seam c o a l 1.31 50 9 Seam p a r t i n g 0.94 51 9 Seam c o a l 0.04 52 9 Seam c o a l 0.06 P 2 O 5 % 157 The phosphorous a n a l y s e s showed t h a t the perc e n t a g e o f phosphorous p r e s e n t i n the c o a l seams and p a r t i n g s was not as s i g n i f i c a n t as was e x p e c t e d . I t was d e c i d e d t o a n a l y z e the samples f u r t h e r u s i n g X-ray d i f f r a c t i o n and S.E.M. t e c h n i q u e s . X-Ray D i f f r a c t i o n and S.E.M. A n a l y s e s X-ray d i f f r a c t i o n d e termined t h a t the c o a l p a r t i n g m a t e r i a l examined was composed of s i d e r i t e . F u r t h e r a n a l y s e s by Scanning E l e c t r o n M i c r o s c o p e a l l o w e d e l e m e n t a l c o m p o s i t i o n s t o be mapped. The s i d e r i t e s p h e r u l e s t h a t make up the framework a re composed p r i m a r i l y o f i r o n and c a l c i u m w i t h minor amounts o f manganese, magnesium, s i l i c a and phosphorous. The m a t r i x i s composed of s i l i c a , s u l f u r , c a l c i u m , phosphorous and i r o n . The s i l i c a i s i n the form o f q u a r t z c r y s t a l s . The phosphorous o c c u r s as minute a p a t i t e c r y s t a l s . I r o n and s u l f u r a r e combined i n p y r i t e c r y s t a l s and f r a m b o i d a l masses. The c a l c i u m may have o c c u r e d i n the c r y s t a l s t r u c t u r e s o f a p a t i t e , s i d e r i t e or c l a y m i n e r a l s . T h i n S e c t i o n A n a l y s e s Ten t h i n s e c t i o n s were examined. S p h e r u l e s ranged from 0.2-1.5 m i l l i m e t r e s i n d i a m e t e r . The c a r b o n a t e s p h e r u l e s were s p h e r i c a l , e l l i p t i c a l o r i r r e g u l a r , i n t e r g r o w n masses. The s p h e r u l e s o c c u r i n t h r e e forms: 1. O r g a n i c remains are s t i l l v i s i b l e a t s p h e r u l e c e n t r e s . O r g a n i c m a t e r i a l i s dark-brown t o opaque and up t o 1 m i l l i m e t r e a c r o s s . Carbonate c r y s t a l s form an o u t e r r i m 0.2-0.5 mm t h i c k ; 2. Homogeneous c a r b o n a t e s p h e r u l e s c o n t a i n i n g c r y s t a l s t h a t 158 r a d i a t e from the c e n t r e . No c e n t r a l o r g a n i c remains a r e v i s i b l e . C r y s t a l t e r m i n a t i o n s are b l u n t t o p o i n t e d . G r a i n b o u n d a r i e s are c o n t i n u o u s . S p h e r u l e s show c e n t r a l c r o s s e s under p l a i n and c r o s s e d p o l a r i z e d i i g h t ; 3. Carbonate s p h e r u l e s t h a t have grown around carbonaceous m a t e r i a l , q u a r t z o r c l a y c r y s t a l s . Some c a r b o n a t e a r e a s a r e diamond-shaped o r i r r e g u l a r . M a t r i c e s were d o m i n a n t l y made up of brown t o opaque o r g a n i c p a r t i c l e s w i t h minor q u a r t z , c h e r t , o p a l and c l a y g r a i n s . Two main ty p e s o f c a r b o n a t e o c c u r as cements; c a r b o n a t e cement rims and s p a r r y c a l c i t e pore f i l l i n g s . O r i g i n s From the s p h e r u l i t e morphology and c o m p o s i t i o n an o r i g i n can be ( p o s t u l a t e d . The o c c u r r e n c e o f s i d e r i t e rims around r e l i c t o r g a n i c m a t e r i a l s u g g e s t s a slow p r e c i p i t a t i o n of s i d e r i t e d i r e c t l y onto o r g a n i c n u c l e i i n the p e a t s . A slow, i n - s i t u c r y s t a l growth i s suggested by i n t e r g r o w n s i d e r i t e c r y s t a l masses and c o n t i n u o u s g r a i n b o u n d a r i e s . In some s p h e r u l i t e s no nu c l e u s i s v i s i b l e s u g g e s t i n g a t o t a l r e c r y s t a l l i z a t i o n of the i n i t i a l m a t e r i a l . In o t h e r s p h e r u l e s , q u a r t z and c l a y p a r t i c l e s a c t e d as n u c l e i . C hemical c o n d i t i o n s f a v o r a b l e f o r s i d e r i t e f o r m a t i o n i n c l u d e low s u l p h i d e a c t i v i t y (low H 2 s p r o d u c t i o n ) , h i g h c a r b o n a t e a c t i v i t y and a h i g h F e 2 + / C a 2 + r a t i o ( B e r n e r , 1964; G a r r e l s and C h r i s t , 1965) . Reducing c o n d i t i o n s a re p r e v a l e n t i n peat swamps where 159 o r g a n i c m a t t e r abounds. F e r r i c o x i d e s and h y d r o x i d e s t r a n s p o r t e d i n t o t h i s environment would be c o n v e r t e d t o s o l u b l e f e r r o u s i o n s (Deans, 1934; C a r r o l l , .1958). C l a y p a r t i c l e a n a l y s e s have suggested k a o l i n i t e and i l l i t e - r i c h s o i l h o r i z o n s on s u r r o u n d i n g l a n d masses. C l a y m i c e l l e s would p r o v i d e s i t e s f o r t r a n s p o r t i n g c o l l o i d a l i r o n o x i d e s and h y d r o x i d e s i n t o the peat environment c r e a t i n g i r o n - r i c h c o n d i t i o n s ( C a r r o l l , 1958). In o r d e r t o a c h i e v e c o n d i t i o n s f a v o r a b l e t o s i d e r i t e forma-t i o n i n the swamp, s e v e r a l c h e m i c a l r e a c t i o n s have t o o c c u r : 1. The a c t i v i t y o f the F e 2 + i o n s would be i n c r e a s e d by the r e d u c t i o n o f f e r r i c o x i d e s (Fe-jO^) f e r r i c h y d r o x i d e s (FeOH-j) and f e r r i c o x y h y d r o x i d e s (FeOOH) ; ex. 4Fe00H + CH 20 + 7H2CC>3 = 4 F e 2 + + 8HC0 3" + 6H 20 2. High carbon d i o x i d e c o n t e n t can be a c h i e v e d through s e v e r a l p r o c e s s e s such a s : a) , b a c t e r i a l o x i d a t i o n of p l a n t d e b r i s as; CH 20 + 0 2 = C 0 2 + H 20 b) . b a c t e r i a l r e d u c t i o n of s u l p h a t e as; 2CH 20 + S 0 4 2 ~ = 2C0 2 + S 2~ + 2H 20 c) . f e r m e n t a t i o n of o r g a n i c m a t t e r ; 2CH 2o = CH 4 + C 0 2 C u r t i s (1977) and I r w i n e t a l . (1977) found t h a t the f e r m e n t a t i o n p r o c e s s was q u a n t i t a t i v e l y the most i m p o r t a n t r e a c t i o n i n the a n a e r o b i c c o n d i t i o n s of swamps where s u l p h a t e i o n s were o r i g i n a l l y s c a r c e . The s p h e r u l e s formed as a d i r e c t p r e c i p i t a t e on o r g a n i c and 160 m i n e r a l n u c l e i . Two s t a g e s o f growth are r e p r e s e n t e d . The i n i t i a l s t age i s r e p r e s e n t e d by s p h e r u l e s w i t h r a d i a t i n g c a r b o n a t e c r y s t a l s . The second stage i s r e p r e s e n t e d by s p h e r u l e s w i t h d i s t i n c t o u t e r c a r b o n a t e rims t h a t r e p r e s e n t the c e s s a t i o n and r e s u m p t i o n of growth. I n - s i t u growth o c c u r r e d i n a c a r b o n a t e - and i r o n - r i c h e nvironment. F i n e - and c o a r s e r - g r a i n e d cements suggest both a s l o w e r p r e c i p i t a t i o n of c a r b o n a t e i n pore spaces and a r a p i d e v a p o r a t i o n of s o l u t i o n s . APPENDIX V -C l a s s i f i c a t i o n P a r t i c l e S i z e C l a s s i f i c a t i o n (Wentworth) Grade L i m i t s (Diameters In mm) B o u l d e r above 256 mm Large c o b b l e Smal1 c o b b l e 256-128 128-64 Very l a r g e p ebble Large pebble Medium pebble S m a l l pebble G r a n u l e 64-32 32-16 16-8 8-4 4-2 Very c o a r s e sand Coarse sand Medium sand F i n e sand Very f i n e sand 2-1 1-1/2 1/2-1/4 1/4-1/8 1/8-1/16 Coarse s i l t Medium s i l t F i n e s i l t V ery f i n e s i l t 1/16-1/32 1/32-1/64 1/64-1/128 1/128-1/256 Coarse c l a y Medium c l a y F i n e c l a y Very f i n e c l a y 1/256-1/512 1/512-1/1024 1/1024-1/2048 1/2048-1/4096 162 APPENDIX VI - R e p r e s e n t a t i v e L i t h o l o g i c Samples From the diamond d r i l l h o l e c o r e t h a t was examined e i g h t c o r e samples were chosen t o e x h i b i t v a r i o u s s e d i m e n t a r y f e a t u r e s found i n d i f f e r e n t d e p o s i t i o n a l e n v i r o n m e n t s . These samples are p r e s e n t e d i n the f o l l o w i n g p l a t e s ( P l a t e s 2-9) . ROCK TYPE: Interbedded Siltstone and Shale, Slightly Rooted and Burrowed. Deformation in the Form of Microfaulting, Dewatering Structure, Distorted or convolute Bedding. L I T H O L O G I C D E S C R I P T I O N : Interbedded siltstone and shale in roughly equal amounts. B e d s may be flat or wavy and show root and burrow structures. Prior to lithification, sediment s u b j e c t to compressive s t r e s s resulting in dewatering f lame structures, convolute bedding and micro-fault ing. T Y P I C A L D E P O S I T I O N A L E N V I R O N M E N T S : Low to moderate energy areas with current velocit ies insufficient to p roduce ripples such a s : current she l te red areas of fluvial and tidal point bars and channel margins, flood plains, d is ta l s p l a y s , b a c k - b a r r i e r l a g o o n s , interdistr ibutary delta f ronts and l evees . Micro-faul t ing favors c l o s e proximity to channe l . F resh water to marine. Plate 2 S a m p l e D 0 1 6 1 6 4 ROCK T Y P E : Lenticular to Wavy-bedded Sandstone with Interbedded Dark Grey Shale and Slump Structure. L I T H O L O G I C D E S C R I P T I O N : Interbedded shale and s a n d s t o n e in roughly equal amounts. Prominant change in bedding orientat ion of s lumped zone . Convolute bedding at upper slump con tac t . T Y P I C A L D E P O S I T I O N A L E N V I R O N M E N T S : Low to modera te energy areas with current velocit ies insufficient to p r o d u c e r ipples, such as: current -shel tered a r e a s of fluvial and tidal point bars and channel margins, distal s p l a y s , back barrier lagoons, interdistributary delta fronts and levees , slumping would favor c lose proximity to a channel . F r e s h water to marine. Plate 3 Sample D 0 1 8 Ib5 ROCK T Y P E : Massive Sandstone with Coa l C lasts L I T H O L O G I C D E S C R I P T I O N : M a s s i v e lithic arenite with c o a l s p a r . May have s o m e c lay and silt. Uniform and devoid of primary sedimentary s t ruc tures . T Y P I C A L D E P O S I T I O N A L E N V I R O N M E N T S : Modera te to high energy s a n d a r e a s of rapid sedimentat ion subject to strong currents a n d / o r w a v e s with abundant a l l o c h t h o n o u s plant detr i tus s u c h as : fluvial and t idal channel bottoms and point b a r s , d istr ibutary mouth bars , splay d e p o s i t s . F r e s h water to mar ine . P L A T E 4 Sample D 0 2 2 166 ROCK TYPE : C rossbedded Quartz Arenite with Coal Spar and Pyrite Cubes. L I T H O L O G I C D E S C R I P T I O N : C l e a n , mass ive to slightly c r o s s b e d d e d quartz sandstone. May have some c lay and silt. Conta ins coai i f ied plant debr is . C o r e commonly b r e a k s a long c o a l s t r e a k s . Pyrite cubes a s s o c i a t e d with c o a l spar and are < 1 c m a c r o s s , a lso as disseminated crystals. . T Y P I C A L D E P O S I T I O N A L E N V I R O N M E N T S : Moderate to high energy sand a r e a s with an influx of al lochthonous or autochthonous plant detritus s u c h a s : fluvial and t idal channel bottoms and bars , distributary mouth bars , sp lay deposi ts , b e a c h e s , b e a c h r idges and dunes. F r e s h water to marine. P la te 5 Sample D 0 2 7 ROCK T Y P E : F laser -bedded Lithic Arenite with Carbonaceous Streaks and Framboidal Pyrite 167 L I T H O L O G I C D E S C R I P T I O N : W a v y - l a m i n a t e d s a n d s t o n e with s h a l e and c o a l i n t e r b e d s . C o a l y l e n s e s have f r a m b o i d a l pyr i te c r y s t a l s (0 .5 mm) on bedding s u r f a c e s . High internal b e d d i n g . Sl ight to m o d e r a t e b u r r o w i n g . T Y P I C A L D E P O S I T I O N A L E N V I R O N M E N T S : Low to m o d e r a t e energy a r e a s with var iab le current v e l o c i t i e s and low to m o d e r a t e levels of infaunal burrowing s u c h a s : d i s t a l c r e v a s s e s p l a y s , f lood p la ins , mixed s a n d / m u d t idal f la ts , t idal point ba rs and channe l m a r g i n s . F r e s h w a t e r to mar ine . Plate 6 S a m p l e D 0 3 1 I £>8 ROCK TYPE: Interbedded Sandstone and Si t ls tone. Lenticular Sandstone slightly Burrowed and Rippled. Sand-f i l led Burrows into Si l tstone. L I T H O L O G I C D E S C R I P T I O N : In terbedded s a n d s t o n e a n d s i l t s t o n e in roughly equal amounts . S a n d in terbeds are r i p p l e - w a v e d and show s c a t t e r e d d i s c r e t e burrows and d i s t u r b e d bedd ing . T Y P I C A L D E P O S I T I O N A L E N V I R O N M E N T S : Low to m o d e r a t e e n e r g y a r e a s s u b j e c t to var iab le current ve loc i t i es and low leve ls of infaunal burrowing s u c h a s : back barr ier l a g o o n s , m ixed s a n d / m u d t idal f la ts , t idal point bars and channel margins , de l ta f ron ts , embayment s h o a l s . B r a c k i s h water to mar ine . Plate 7 S a m p l e D 0 5 6 ROCK TYPE : F l a s e r - b e d d e d Lithic Arenite with Rippled Shale St reaks , Slightly Burrowed. L I T H O L O G I C D E S C R I P T I O N : L i th ic a ren i te with thin s h a l e p a r t i n g s . S a n d s t o n e s and s h a l e s are l e n s - s h a p e d to w a v y . S a n d s t o n e s h a v e s m a l l - s c a l e c r o s s b e d d i n g and s c a t t e r e d , d i s c r e t e bur rows . T Y P I C A L D E P O S I T I O N A L E N V I R O N M E N T : Low to m o d e r a t e e n e r g y a r e a s with v a r i a b l e current ve loc i ty s u c h a s : middle to upper por t ions of t idal and f luvial point b a r s , s p l a y s , embayment s h o a l s , b a c k - b a r r i e r l a g o o n s , in te rd is t r ibu ta ry de l ta f ron ts . Low leve ls of burrowing favor high sed iment supply or cont inual w a v e a n d / o r current rework ing of b e d s . F r e s h wa te r to mar ine. P late 8 S a m p l e D 0 5 7 I 70 ROCK T Y P E : F l a s e r - B e d d e d , Rippled Lithic Arenite, Moderately Burrowed, Fining to Carbonaceous , Pyritized Sandstone. L I T H O L O G I C D E S C R I P T I O N : F l a s e r b e d d e d lithic a ren i te with s m a l l - s c a l e internal c r o s s b e d d i n g . R e a c t i v a t i o n s u r f a c e s c o m m o n . Burrowing common. S a n d s t o n e b e c o m e s s h a l i e r at top with c o a l l e n s e s . Pyr i t e nodules ( 2 - 3 cm) h a v e grown in c o a l y s h a l e and d e f o r m e d b e d d i n g . T Y P I C A L D E P O S I T I O N A L E N V I R O N M E N T S : S a n d y a r e a s with low to moderate v e l o c i t y r ipp le - fo rming cur ren ts and m o d e r a t e infaunal burrowing s u c h a s : mixed s a n d - m u d t ida l f l a ts , d is ta l c r e v a s s e s p l a y s and flood pla ins, channel margins . B r a c k i s h to marine. P late 9 Sample D O 6 0 171 Appendix VII SYMBOLS Climbing r ipples Ripple = • Hor izonta l para l le l laminae C - ^ 3 Churned Convo lu te lamination Roots ~ \ J ~ ~ Burrow 0 C o n c r e t i o n s O L o a d c a s t F o s s i l plants R i p - u p c las t (coal ) <V Slump structure R i p - u p c l a s t (arg i l laceous) — ^ — Flame st ructure / / / / / / / / P lanar x - b e d n o n - t a n g e n t i a l ZrE^i Sha le JJJJJ P lanar x - b e d tangential WEM S i l ts tone Sharp contact S a n d s t o n e Eros iona l contact IZZtt Cong lomera te (No symbol) Grada t iona l contact 3 B B t C o a l 172 REFERENCES A l l e n , J.R.L., 1965. A Review of the O r i g i n and C h a r a c t e r i s t i c s of Recent A l l u v i a l Sediments; Sedimentology v.5, p.89-191. A l l e n , J.A. and J.L. C a r r , 1947. Geology of Highwood-Elbow a r e a , A l b e r t a ; Research C o u n c i l of A l b e r t a , Report 49. Anderson, J.A.R., 1964. The S t r u c t u r e and Development of the Peat Swamps of Sarawak and B r u n e i ; J o u r n a l o f T r o p i c a l Geography v. 18, p. 7-16. B a l s l e y , J.K., 1980. C r e t a c e o u s Wave-Dominated D e l t a Systems: Book C l i f f s , E a s t C e n t r a l Utah. A F i e l d Guide; Amoco P r o d u c t i o n Company, 163 p. Beach, H.H., 1943. Moose mountain and M o r l e y Map A r e a s , A l b e r t a ; G e o l o g i c a l Survey o f Canada Memoir 236. Beerbower, J.R., 1964. Cyclothems and C y c l i c D e p o s i t i o n a l Mechanisms i n A l l u v i a l P l a i n S e d i m e n t a t i o n : i n D.F. Merriam, ed., Symposium on C y c l i c S e d i m e n t a t i o n ; S t a t e G e o l o g i c a l Survey of Kansas, B u l l e t i n 169, p. 31-42. B e l l , W.A., 1956. Lower C r e t a c e o u s f l o r a s of Western Canada; G e o l o g i c a l Survey o f Canada Memoir 285. B e r n e r , R.A., 1964. S t a b i l i t y F i e l d s of I r o n M i n e r a l s i n A n a e r o b i c Marine Sediments; J o u r n a l o f Geology 72, p. 826-834 . B e r n e r , R.A., 1971. P r i n c i p l e s of Chemical Sedimentology; McGraw H i l l Book Company, New York, 24Op. B u s t i n , R.M., 1979. S t r u c t u r a l F e a t u r e s of C o a l Measures of the Kootenay F o r m a t i o n , S o u t h e a s t e r n Canadian Rocky Mountains; U n p u b l i s h e d M.Sc. T h e s i s , U n i v e r s i t y of B r i t i s h C olumbia, 191p. B u s t i n , R.M., 1982. The E f f e c t of S h e a r i n g on the Q u a l i t y o f Some C o a l s i n the S o u t h e a s t e r n Canadian C o r d i l l e r a ; The Canadian M i n i n g and M e t a l l u r g i c a l B u l l e t i n v. 75, no. 841, p. 76-83. B u s t i n , R.M. and P. B a y l i s s , 1979. C l a y M i n e r a l o g y o f the Eureka Sound and B e a u f o r t F o r m a t i o n s , A x e l H e i b e r g and West C e n t r a l E l l e s m e r e I s l a n d s , E a s t e r n Canadian A r c t i c A r c h i p e l a g o ; B u l l e t i n of Canadian P e t r o l e u m Geology v. 27, no. 4, p. 446-452. B u s t i n , R M., W.S. Styan and L.E. Lowe, 1983. V a r i a b i l i t y of S u l p h u r and Ash i n Humid-Temperate Peat s o f the F r a s e r 173 R i v e r D e l t a , B r i t i s h Columbia; XI Congress on C a r b o n i f e r o u s S t r a t i g r a p h y , Compte Rende, M a d r i d . C a i r n e s , D.D., 1914. Moose Mountain D i s t r i c t , Southern A l b e r t a ; G e o l o g i c a l Survey o f Canada Memoir 61, 62p. Cameron, A.R., 1972. P e t r o g r a p h y o f Kootenay C o a l s i n t h e Upper E l k R i v e r and Crowsnest A r e a s , B r i t i s h Columbia and A l b e r t a : i n G.B. M e l l o n , J.W. Kramers and E . J . S e a g e l , eds., P r o c e e d i n g s of the F i r s t G e o l o g i c a l Conference on Western Canadian C o a l ; Research C o u n c i l of A l b e r t a , I n f o r m a t i o n S e r i e s no. 60, p. 31-46. C a r r o l , D., 1958. Role o f C l a y M i n e r a l s i n the T r a n s p o r t a t i o n of I r o n ; Geochimica Et Cosmochimica A c t a 14, p. 1-27. Cohen, A.D. and W. Spackman, 1977. P h y t o g e n i c O r g a n i c Sediments and Sedimentary Environments i n the Everglades-Mangrove Complex; P a l a e o n t o g r a p h i c a A b s t r a c t B, 162, 144p. Coleman, J.M., 1966. E c o l o g i c a l Changes i n a M a s s i v e Fresh-Water C l a y Sequence; G u l f Coast A s s o c i a t i o n of G e o l o g i c a l S o c i e t i e s T r a n s a c t i o n s v. 16, p. 159-174. Coleman, J.M., 1969. Brahmaputra R i v e r : Channel P r o c e s s e s and S e d i m e n t a t i o n ; Sedimentary Geology v. 3, p. 129-239. C u r r a y . J.R., F . J . Emmel and P.J.S. Crampton, 1969. Holocene H i s t o r y o f a S t r a n d P l a i n , Lagoonal C o a s t , N a y a r i t , Mexico: i n A.A. C a s t a n a r e s , F.B. P h l e g e r , eds., C o a s t a l Lagoons, a Symposium, Mexico: U n i v e r s i d a d N a c i o n a l Autonoma, p. 63-100 . C u r t i s , C D . , 1977. Sedimentary Geochemistry: Environments and P r o c e s s e s Dominated by Involvement o f Aqueous Phases; P h i l -o s o p h i c a l T r a n s a c t i o n s o f the R o y a l S o c i e t y o f London A286, p. 353-372. D a h l s t r o m , CD.A., 1970. S t r u c t u r a l Geology i n the E a s t e r n Margin o f the Canadian Rocky Mountains; B u l l e t i n o f Canadian P e t r o l e u m Geology v. 18, no. 3, p. 332-406. Deans, T., 1934. The S p h e r u l i t i c I r o n s t o n e s of West Y o r k s h i r e ; Geology Magazine 71, p. 49-65. E l l i o t , T., 1974. I n t e r d i s t r i b u t a r y Bay Sequences and T h e i r G e n e s i s ; Sedimentology v. 21, p. 611-622. E l l i o t , T., 1978. C l a s t i c S h o r e l i n e s : i n H.G. Reading, ed., Sedimentary Environments and F a c i e s , E l s e v i e r , New York, p. 143-175. E t h r i d g e , F.G., T.J. J a c k s o n and A.D. Youngberg, 1981. F l o o d b a s i n Sequence of a F i n e - G r a i n e d Meander B e l t 174 Subsystem: the C o a l - B e a r i n g Lower Wasatch and Upper F o r t Union F o r m a t i o n s Southern Powder R i v e r B a s i n , Wyoming; Soc-i e t y of Economic P a l e o n t o l o g i s t s and M i n e r a l o g i s t s S p e c i a l P u b l i c a t i o n no. 31, p. 191-209. F i s h e r , W.L., 1968. V a r i a t i o n s i n L i g n i t e s of F l u v i a l , D e l t a i c and Lagoonal Systems, W i l c o x Group (Eocene), Texas ( a b s t r a c t ) , G e o l o g i c a l S o c i e t y o f America Annual M e e t i n g Program With A b s t r a c t s , p. 97. F i s k , H.N., 1960. Recent M i s s i s s i p p i S e d i m e n t a t i o n and Peat A c c u m u l a t i o n ; Compte Rendu, 4th C a r b o n i f e r o u s Congress, H e e r l e n , 1958, v. I , p. 187-199. F l o r e s , R.M., 1980. Comparison of D e p o s i t i o n a l Models of T e r t i a r y and Upper C r e t a c e o u s C o a l - B e a r i n g Rocks i n Some Western I n t e r i o r B a s i n s of the U n i t e d S t a t e s : P r o c e e d i n g s of the 4th Symposium on the Geology of Rocky Mountain C o a l ; C o l o r a d o G e o l o g i c a l Survey Research S e r i e s 10, p. 17-20. F l o r e s , R.M.-, 1981. C o a l D e p o s i t i o n i n F l u v i a l P a l e o e n v i r o n m e n t s of the Paleocene Tongue R i v e r Member of the F o r t Union F o r m a t i o n , Powder R i v e r A r e a , Powder R i v e r B a s i n , Wyoming and Montana; S o c i e t y o f Economic P a l e o n t o l o g i s t s and M i n e r a l o g i s t s S p e c i a l P u b l i c a t i o n no. 31, p. 169-190. F l o r e s , R.M. and F.G. E t h r i d g e , 1981. Nonmarine D e p o s i t s and the S e a r c h For Energy Resources and M i n e r a l s ; S o c i e t y of Economic P a l e o n t o l o g i s t s and M i n e r a l o g i s t s S p e c i a l P u b l i c a t i o n no. 31, p. 1-17. F r e b o l d , H., 1957. The J u r a s s i c F e r n i e Group i n the Canadian Rocky Mountains and F o o t h i l l s ; G e o l o g i c a l Survey o f Canada Memoir 287, 197p. G a r r e l s , R.M. and C L . C h r i s t , 1965. S o l u t i o n s , M i n e r a l s and E q u i l i b r i a ; Harper and Row, New York, N.Y., 450p. G e r s i b , G.A. and P.J. McCabe, 1981. C o n t i n e n t a l C o a l - B e a r i n g Sediments of the P o r t Hood F o r m a t i o n ( C a r b o n i f e r o u s ) , Cape L i n z e e , Nova S c o t i a , Canada; S o c i e t y of Economic P a l e o n t o l o g i s t s and M i n e r a l o g i s t s S p e c i a l P u b l i c a t i o n no. 31, p. 95-108. G i b s o n , D.W., 1977. Sedimentary F a c i e s i n the J u r a - C r e t a c e o u s Kootenay F o r m a t i o n , Crowsnest Pass A r e a , Southwestern A l b e r t a and S o u t h e a s t e r n B r i t i s h Columbia; B u l l e t i n o f Canadian P e t r o l e u m Geology, v. 25, no. 4, p. 767-791. G i b s o n , D.W., 1979. The M o r r i s e y and M i s t Mountain F o r m a t i o n s -Newly D e f i n e d L i t h o s t r a t i g r a p h i c U n i t s of the J u r a - C r e t a c e o u s Kootenay Group, A l b e r t a and B r i t i s h C o lumbia; B u l l e t i n o f Canadian P e t r o l e u m Geology, v. 27, no. 2, p. 183-208. 175 G i b s o n , D.W. and J.D. Hughes, 1981. S t r u c t u r e , S t r a t i g r a p h y , Sedimentary Environments and C o a l D e p o s i t s o f the J u r a - C r e t a c e o u s Kootenay Group, Crowsnest Pass A r e a , A l b e r t a and B r i t i s h Columbia; i n F i e l d Guides t o Geology and M i n e r a l D e p o s i t s , C a l g a r y '81 G e o l o g i c a l A s s o c i a t i o n of C a n a d a - M i n e r a l o g i c a l A s s o c i a t i o n of Canada-Canadian G e o p h y s i c a l Union 1981. Graham, P.S., P.R. Gunther, D.W. G i b s o n , 1977. G e o l o g i c a l I n v e s t i g a t i o n s of the C o a l - B e a r i n g Kootenay F o r m a t i o n i n the S u b s u r f a c e of the Upper E l k R i v e r V a l l e y , B r i t i s h Columbia - P r o j e c t 760056; G e o l o g i c a l Survey of Canada Paper 77-1B (1977), Report of A c t i v i t i e s , P a r t B., p. 203-210. Gray, T.D., C.E. Bowen and J.E. Trummel, 1982. D e p o s i t i o n a l S t u d i e s o f the E a r l y Paleocene J i m B r i d g e r C o a l D e p o s i t s and i t s A p p l i c a t i o n t o S u r f a c e Mine Problems; Utah G e o l o g -i c a l and M i n e r a l o g i c a l Survey B u l l e t i n 118, p. 102-115. Groenwold, G.H., B.W. Rehm and J.A. C h e r r y , 1981. D e p o s i t i o n a l S e t t i n g and Groundwater Q u a l i t y i n C o a l - B e a r i n g Sediments and S p o i l s i n Western N o r t h Dakota; S o c i e t y of Economic P a l e o n t o l o g i s t s and M i n e r a l o g i s t s S p e c i a l P u b l i c a t i o n no. 31, p. 157-167. Hacquebard, D.A. and J.R. Donaldson, 1974. Rank S t u d i e s of C o a l s i n the Rocky Mountains and Inner F o o t h i l l s B e l t , Canada; G e o l o g i c a l Survey of America S p e c i a l Paper 153, p. 75-94. Hamblin, A.P. and R.G. Walker, 1979. Storm Dominated S h a l l o w Marine D e p o s i t s : The F e r n i e - K o o t e n a y ( J u r a s s i c ) T r a n s i t i o n Southern Rocky Mountains; Canadian J o u r n a l of E a r t h S c i e n c e s v. 16, p. 1673-1690. Harms, J . C , J.B. S o u t h a r d , D.C. S p e a r r i n g and R.G. Walker, eds., 1975. D e p o s i t i o n a l Environments as I n t e r p r e t e d From P r i m a r y Sedimentary S t r u c t u r e s and S t r a t i f i c a t i o n Sequences, L e c t u r e N o t e s , S o c i e t y of Economic P a l e o n t o l o g i s t s and M i n e r a l o g i s t s S h o r t Course no. 2, D a l l a s , Texas, A p r i l 5, 1975, 161p. Hayes, M.O. and T.W. Kana, 1979. T e r r i g e n o u s C l a s t i c D e p o s i t i o n a l E n v i r o n m e n t s , Some Modern Examples; American A s s o c i a t i o n of P e t r o l e u m G e o l o g i s t s T e c h n i c a l Report no. 11-CRD, I-40-I-50. Home, J . C , J.C. Ferm, F.T. C a r r u c i o and B.P. Baganz, 1978 . D e p o s i t i o n a l Models i n C o a l E x p l o r a t i o n and Mine P l a n n i n g i n A p p a l a c h i a n Region; American A s s o c i a t i o n of P e t r o l e u m G e o l o g i s t s B u l l e t i n v. 62, no. 12, p. 2379-2411. Houseknecht, D.W. and A.T. I a n n a c c h i o n e , 1982. A n t i c i p a t e d F a c i e s - R e l a t e d C o a l M i n i n g Problems i n H a r t s h o r n e 176 F o r m a t i o n , Arkoma B a s i n ; American A s s o c i a t i o n of P e t r o l e u m G e o l o g i s t s B u l l e t i n v. 66, no. 7, p. 923-946. Hughes, J.D., 1981. L i t h o l o g y , D e p o s i t i o n a l S e t t i n g and C o a l Rank-Depth R e l a t i o n s h i p s i n the J u r a s s i c - C r e t a c e o u s Kootenay Group a t Mount A l l e n , Cascade C o a l b a s i n , A l b e r t a , W i t h C o n t r i b u t i o n s by A.R. Cameron, G e o l o g i c a l Survey of Canada Paper 81-111. I r w i n , H., C. C u r t i s and M. Coleman, 1977. I s o t o p i c E v i d e n c e For Source of D i a g e n e t i c Carbonates Formed D u r i n g B u r i a l of O r g a n i c - r i c h Sediments; Nature 269, p. 209-213. J a n s a , L., 1972. D e p o s i t i o n a l H i s t o r y of the C o a l - B e a r i n g Upper J u r a s s i c - L o w e r C r e t a c e o u s Kootenay F o r m a t i o n , Southern Rocky M o u n t a i n s , Canada; G e o l o g i c a l A s s o c i a t i o n o f Canada B u l l e t i n v. 83, p. 3199-3222. K a l k r e u t h , W.D., 1982. Rank and P e t r o g r a p h i c C o m p o s i t i o n of S e l e c t e d J u r a s s i c - L o w e r C r e t a c e o u s C o a l s of B r i t i s h C o l umbia, Canada; B u l l e t i n of Canadian P e t r o l e u m Geology v. 30, no. 2, p. 112-139. Leach, W.W. , 1912. Geology o f B l a i r m o r e Map-Area, A l b e r t a ; G e o l o g i c a l Survey o f Canada Summary Report 1911, p. 192-200. L e e d e r , M.R., 1978. A Q u a n t i t a t i v e S t r a t i g r a p h i c Model For A l l u v i u m , With S p e c i a l R e f e r e n c e To Channel D e p o s i t D e n s i t y and I n t e r c o n n e c t e d n e s s ; i n A.D. M i a l l , ed., F l u v i a l S e d i m e n t o l o g y , p. 587-596. L e r a n d , M.M., 1976. The Sedimentology of S e l e c t e d C l a s t i c O i l and Gas R e s e r v o i r s i n A l b e r t a ; Canadian S o c i e t y of P e t r o l e u m G e o l o g i s t s Core C o n f e r e n c e , p. 125. L e o p o l d , L.B. and M.G. Wolman, 1957. R i v e r Channel P a t t e r n s : B r a i d e d , Meandering and S t r a i g h t ; U n i t e d S t a t e s G e o l o g i c a l Survey P r o f e s s i o n a l Paper 282-B, p. 39-85. L e o p o l d , L.B., M.G. Wolman and J.P. M i l l e r , 1964. F l u v i a l P r o c e s s e s i n Geomorphology; W.H. Freeman and Co., San F r a n s i s c o , 522p. Loughnan, F.C., 1969. Chemical Weathering of S i l i c a t e M i n e r a l s ; New Y o r k , E l s e v i e r , 154p. Massoth, T.W. , 1982. D e p o s i t i o n a l Environments o f a S u r f a c e Coal Mine i n Northwest C o l o r a d o ; Utah G e o l o g i c a l and M i n e r a l o g i c a l Survey B u l l e t i n 118, p. 115-120. Matsumoto, R. and A. I i j i m a , 1981. O r i g i n and D i a g e n e t i c E v o l u t i o n o f Ca-Mg-Fe Carbonates i n Some C o a l f i e l d s of Japan; Sedimentology, v. 28, p. 239-259. 177 McEvoy, J . , 1902. Crowsnest C o a l - F i e l d s , E a s t Kootenay D i s t r i c t , B.C.; G e o l o g i c a l Survey of Canada Map 767. McEvoy, J . and W.W. Leach, 1902. G e o l o g i c a l and T o p o g r a p h i c a l Map o f Crowsnest C o a l - F i e l d s , E a s t Kootenay D i s t r i c t , B.C.; G e o l o g i c a l Survey of Canada. McLean, J.R., 1977. The Cadomin F o r m a t i o n : S t r a t i g r a p h y , S e d i m e n t o l o g y , and T e c t o n i c I m p l i c a t i o n s ; B u l l e t i n o f Cana-d i a n P e t r o l e u m Geology, v. 25, no. 4, p.792-827. McLean, J.R. and T. J e r z y k i e w i c z , 1978. C y c l i c i t y , T e c t o n i c s and C o a l : Some A s p e c t s of F l u v i a l S edimentology i n the Brazeau-Paskapoo F o r m a t i o n s , C o a l V a l l e y A r e a , A l b e r t a , Canada; i n A.D. M i a l l , ed., F l u v i a l S e d i m e n t o l o g y , p. 441-468 N e l s o n , S.J., 1970. The Face of Time, The G e o l o g i c a l H i s t o r y of Western Canada, A l b e r t a A s s o c i a t i o n o f P e t r o l e u m G e o l o g i s t s , p. 114-118. . Newmarch, C.G., 1953. Geology of the Crowsnest C o a l B a s i n , W ith S p e c i a l R e f e r e n c e t o the F e r n i e A r e a ; B r i t i s h Columbia Department of Mines B u l l e t i n 38. N o r r i s , D.K., 1959. Type S e c t i o n o f the Kootenay F o r m a t i o n , G r a s s y Mountain, A l b e r t a ; J o u r n a l o f A l b e r t a S o c i e t y o f P e t r o l e u m G e o l o g i s t s v. 7, p. 223-233. N o r r i s , D.K., 1964. M i c r o t e c t o n i c s o f the Kootenay F o r m a t i o n Near F e r n i e , B r i t i s h Columbia; B u l l e t i n o f Canadian P e t r o l e u m G e o l o g i s t s S p e c i a l Guide-Book I s s u e , F l a t h e a d V a l l e y , v. 12, p. 383-398. N o r r i s , D.K., 1971. Comparative Study of the C a s t l e R i v e r and Other F o l d s i n the E a s t e r n C o r d i l l e r a o f Canada; G e o l o g i c a l Survey of Canada B u l l e t i n 205, 58p. Oomkens, E., 1967. D e p o s i t i o n a l Sequences and Sand D i s t i b u t i o n i n a D e l t a i c Complex: A S e d i m e n t o l o g i c a l I n v e s t i g a t i o n of the P o s t - G l a c i a l Rhone D e l t a Complex; G e o l o g i e En Mijnbouw, v. 46, p. 265-278. P e a r s o n , D.E. and D.A. G r i e v e , 1980. C o a l I n v e s t i g a t i o n s , E l k V a l l e y C o a l f i e l d ( 8 2 J / 2 ) ; B r i t i s h Columbia M i n i s t r y of Energy, Mines and P e t r o l e u m Resources Paper 1980-1, p. 91-96. P e t t i j o h n , F . J . , P.E. P o t t e r and R. S i e v e r , 1972. Sand and Sandstone; New Y ork, S p r i n g e r V e r l a g , 612p. Pocock, S.A.J., 1964. P a l y n o l o g y of the Kootenay F o r m a t i o n a t i t s Type S e c t i o n ; B u l l e t i n of Canadian P e t r o l e u m Geology, S p e c i a l Guidebook I s s u e , F l a t h e a d V a l l e y , v. 12, p. 500-178 512. Postma, D., 1981. F o r m a t i o n of S i d e r i t e and V i v i a n i t e and the Pore-Water C o m p o s i t i o n o f a Recent Bog Sediment i n Denmark; Chemical Geology, v. 31, p. 225-244. P o t t e r , P.E., J.B. Maynard and W.A. P r y o r , 1980. Sedimentology of S h a l e - Study Guide and R e f e r e n c e Source; S p r i n g e r V e r l a g , New York, H e i d e l b e r g , B e r l i n , 305p. P r i c e , R.A., 1962. F e r n i e Map A r e a , E a s t H a l f , A l b e r t a and B r i t i s h C olumbia, 82G E l / 2 ; G e o l o g i c a l Survey o f Canada Paper 61-24. P r i c e , R.A., 1965. F l a t h e a d Map A r e a , B r i t i s h Columbia and A l b e r t a ; G e o l o g i c a l Survey of Canada Memoir 336. Rapson, J.E., 1965. P e t r o g r a p h y and D e r i v a t i o n of J u r a s s i c -C r e t a c e o u s C l a s t i c Rocks, Southern Rocky Mountains Canada; American A s s o c i a t i o n o f P e t r o l e u m G e o l o g i s t s B u l l e t i n v. 49, p. 1426-1452. Reading, H.G., ed., 1978. Sedimentary Environments and F a c i e s ; E l s e v i e r , New York, 557p. R e i n e c k , H.E. and I.B. S i n g h , 1980. D e p o s i t i o n a l Sedimentary Environments - With R e f e r e n c e t o T e r r i g e n o u s e l a s t i c s ; S p r i n g e r - V e r l a g , B e r l i n H e i d e l b e r g New York, 549p. Rose, B. , 1917. Crowsnest C o a l F i e l d , A l b e r t a ; G e o l o g i c a l Survey of Canada Summary Report 1916, p. 107-114. Rouse, G.E., 1959. P l a n t M i c r o f o s s i l s From Kootenay C o a l Measures S t r a t a o f B r i t i s h Columbia; M i c r o p a l e o n t o l o g y , v. 5, p. 303-324. S c h o l l , D.W., 1969. Modern Mangrove Swamp S t r a t i g r a p h y and the I d e a l Cyclothem: i n E.D. Dapples and M.E. H o p k i n s , eds., Environments o f C o a l D e p o s i t i o n , G e o l o g i c a l S o c i e t y of America S p e c i a l Paper no. 114, p. 37-61. Schumm, S.A., 1981. E v o l u t i o n and Response of the F l u v i a l System, S e d i m e n t o l o g i c I m p l i c a t i o n s ; S o c i e t y of Economic P a l e o n t o l o g i s t s and M i n e r a l o g i s t s S p e c i a l P u b l i c a t i o n no. 31, p. 19-29. ) S m i t h , D.G. and N.D. Smith, 1980. S e d i m e n t a t i o n i n Anastomosed R i v e r Systems: Examples From A l l u v i a l V a l l e y s Near B a n f f , A l b e r t a ; J o u r n a l o f Sedimentary P e t r o l o g y v. 50, p. 157-164. 179 Spackman, W. , W.L. R i e g e l and C P . D o l s e n , 1969. G e o l o g i c a l and B i o l o g i c a l I n t e r a c t i o n s i n the Swamp-Marsh Complex of Southe r n F l o r i d a : i n E.D. Dapples and M.E. Hopk i n s , eds., Environments o f Co a l D e p o s i t i o n ; G e o l o g i c a l S o c i e t y of America S p e c i a l Paper no. 114, p. 1-35. Sp e a r s , D.A. and M.a. Amin, 1981. Geochemistry and M i n e r a l o g y of Marine Namurian B l a c k S h a l e s From the T a n s l e y B o r e h o l e , D e r b y s h i r e ; S e d i m e n t o l o g y , v. 28, p. 407-417. S t a c h , E., M.-Th. Mackowsky, M. T e i c h m u l l e r , G.H. T a y l o r , D. Chandra and R. T e i c h m u l l e r , 1982. St a c h ' s Textbook of Co a l P e t r o l o g y ; Gebruder B o r n t r a e g e r , B e r l i n , S t u t t g a r t , 535p. Staub, J.R. and A.D. Cohen, 19 79. The Snuggedy Swamp of South C a r o l i n a : A Back B a r r i e r E s t u a r i n e C o a l - F o r m i n g Environment; J o u r n a l o f Sedimentary P e t r o l o g y 49, p. 133-144. S t e l c k , C.R., J.H. W a l l , G.D. W i l l i a m s and G.B. M e l l o n , 1972. The C r e t a c e o u s and J u r a s s i c o f the F o o t h i l l s of the Rocky Mountains of A l b e r t a ; XXIV I n t e r n a t i o n a l G e o l o g i c a l Congress, Canada, F i e l d E x c u r s i o n A20 Guidebook. S t y a n , W.B., 1981. The Sedim e n t o l o g y , P e t r o l o g y and Geochemistry of Some F r a s e r D e l t a Peat D e p o s i t s ; U n p u b l i s h e d M.Sc". T h e s i s , U n i v e r s i t y of B r i t i s h C olumbia, 188p. St y a n , W.B. and R.M. B u s t i n , 1983a. P e t r o g r a p h y of Some F r a s e r R i v e r D e l t a Peat D e p o s i t s : C o a l M a c e r a l and M i c r o l i t h o t y p e P r e c u r s o r s i n Temperate-Climate P e a t s ; I n t e r n a t i o n a l J o u r n a l of Co a l Geology, 2, p. 321-370. S t y a n , W.B. and R.M. B u s t i n , 1983b. Sedimentology o f F r a s e r R i v e r D e l t a Peat D e p o s i t s : A Modern Analogue For Some C o a l s ; I n t e r n a t i o n a l J o u r n a l o f Co a l Geology, 3, p. 101-143. T a p l i n , A.C., 1976. G e n e r a l Geology and G e o l o g i c a l P r a c t i c e s a t F o r d i n g C o a l ; Paper P r e s e n t e d a t Canadian I n s t i t u t e of M i n i n g and M e t a l l u r g y D i s t r i c t 6 C o n v e n t i o n , Vancouver, B r i t i s h C o lumbia, October 15, 1976, 13p. T e i c h m u l l e r , M. and R. T e i c h m u l l e r , 1982. The G e o l o g i c a l B a s i s o f C o a l F o r m a t i o n ; i n E. St a c h e t a l . , S t a c h ' s Textbook of C o a l P e t r o l o g y , Gebruder B o r n t r a e g e r , B e r l i n , S t u t t g a r t , p. 5-82. V i s h e r , G.S., 1965. Use o f V e r t i c a l P r o f i l e i n E n v i r o n m e n t a l R e c o n s t r u c t i o n ; American A s s o c i a t i o n of P e t r o l e u m G e o l o g i s t s B u l l e t i n v. 49, no. 1, p. 41-61. Walker, R.G., 1980. F a c i e s Models; Ge o s c i e n c e Canada R e p r i n t S e r i e s 1, G e o l o g i c a l A s s o c i a t i o n of Canada, 211p. 180 Walker, R.G. and D.J. Cant, 1980. Sandy F l u v i a l Systems: i n R.G. W a l k e r , ed., F a c i e s Models, G e o s c i e n c e s Canada R e p r i n t S e r i e s 1, p. 23-31. W i l l i a m s , E. G. and M.L. K i e t h , 1963. R e l a t i o n s h i p Between S u l f u r i n C o a l s and the Occurrences o f Marine Roof Beds; Economic Geology v. 58, p. 720-729. W r i g h t , L.D. and J.M. Coleman, 1973. V a r i a t i o n s i n Morphology of Major R i v e r D e l t a s as F u n c t i o n s of Ocean Wave and R i v e r D i s c h a r g e Regimes; American A s s o c i a t i o n o f P e t r o l e u m G e o l o g i s t s B u l l e t i n v. 57, no. 2, p. 370-398. W u n d e r l i c h , F., 1971. Der G o l f von Gaeta ( T y r r h e n i s c h e s Meer), I I . S t r a n d a u f b a u und Stranddynamik; Senckenbergiana M a r i t 3, p. 135-183. Z o b e l l , C.E., 1963. O r g a n i c G e o c h e m i s t r y of S u l f u r : i n I.A. B e r g e r , ed., Advances i n O r g a n i c G e o c h e m i s t r y , Pergamon P r e s s , p. 573-578. 

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