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Quaternary geology : Coquitlam-Port Moody area, British Columbia Hicock, Stephen Robert 1976

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QUATERNARY GEOLOGY: COQUITLAM-PORT MOODY AREA, BR IT I SH COLUMBIA by S t e p h e n R o b e r t H i c o c k B. S c . , U n i v e r s i t y o f B r i t i s h C o l u m b i a , 1 9 7 3 A T h e s i s S u b m i t t e d i n P a r t i a l F u l f i l l m e n t o f t h e R e q u i r e m e n t s f o r t h e Deg r ee o f MASTER OF SCIENCE i n The F a c u l t y o f G r a d u a t e S t u d i e s ( D e p a r t m e n t o f 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 t h e r e q u i r e d s t a n d a r d THE UN IVERS ITY OF BR IT I SH COLUMBIA J u n e , 1 9 7 6 © w Stephen Robert Hicock, 1976 In presenting th i s thes is in pa r t i a l fu l f i lment of the requirements for an advanced degree at the Un ivers i ty of B r i t i s h Columbia, I agree that the L ibrary sha l l make it f ree ly ava i l ab le for reference and study. for s cho la r l y purposes may be granted by the Head of my Department or by his representat ives. It is understood that copying or pub l i ca t ion of th is thes is for f inanc ia l gain sha l l not be allowed without my writ ten permission. Department of G- &<S /C^l. The Univers i ty of B r i t i s h Columbia 20 75 Wesbrook P l a c e Vancouver, Canada V6T 1W5 I fur ther agree that permission for extensive copying of th is thes is Date ^8JTU/L^ 7& Frontspiece: Stereo pair of Mary Hill Gravel Pit, Port Coquitlam, B.C. as it appeared in March, 1974. ABSTRACT D u r i n g Q u a t e r n a r y t i m e t h e C o q u i1 1 a m - P o r t Moody a r e a u n d e r w e n t two and p o s s i b l y t h r e e m a j o r g l a c i a t i o n s s e p a r a t e d by n o n g l a c i a l i n t e r v a l s . Each g l a c i a t i o n was a c c o m p a n i e d by e u s t a t i c and i s o s t a t i c s e a - l e v e l c h a n g e s o f up t o 230 m, r e l a t i v e t o p r e s e n t sea l e v e l , and p r o b a b l y some t e c t o n i c a d j u s t m e n t . A s s o c i a t e d w i t h e a c h m a j o r i c e a d v a n c e we re two o r t h r e e l o c a l i c e a d v a n c e s r e p r e s e n t e d by t i l l s s e p a r a t e d by o u t w a s h d e p o s i t s . D u r i n g t h e l a s t m a j o r g l a c i a t i o n ( F r a s e r ) , two s t a d e s o c c u r r e d (Va shon and C o q u i t l a m ) , p o s s i b l y s e p a r a t e d by an i n t e r s t a d e ( Q u a d r a ) . The C o q u i t l a m S t a d e was t h e e a r l i e s t and i s r e p r e s e n t e d by t h e C o q u i t l a m D r i f t ( b e t w e e n 2 5 , 0 0 0 and 2 1 , 6 0 0 r a d i o c a r b o n y r . B . P . ) w h i c h has no t been r e c o g n i z e d b e f o r e on t h e B. C. m a i n l a n d ; i t may c o r r e l a t e w i t h t h e Evans C r e e k S t a d e d i s c o v e r e d i n n o r t h w e s t e r n W a s h i n g t o n . N i n e f o r m -a t i o n a l 1 i t h o s t r a t i g r a p h i c u n i t s a r e mapped and d e s c r i b e d f o r -t h e a r e a , e a c h p r o b a b l y r e p r e s e n t i n g a g e o 1 o g i c - c 1 i m a t i c u n i t . The u n i t s a r e s e p a r a t e d by u n c o n f o r m i t i e s r e p r e s e n t i n g t h r e e -d i m e n s i o n a l i r r e g u l a r b u r i e d l a n d s c a p e s w h i c h w e r e r e s h a p e d and r e p l a c e d by new o n e s . C o n s e q u e n t l y , t h e Q u a t e r n a r y s t r a t i -g r a p h y i s e x t r e m e l y c o m p l e x and s e d i m e n t u n i t s o c c u r s p o r a d i -c a l l y . C o r r e l a t i o n s ba sed on o t h e r t h a n a t h r e e - d i m e n s i o n a l s t u d y a r e a t b e s t t e n t a t i v e and must be s u p p o r t e d by r a d i o -c a r b o n d a t e s . The t o p o g r a p h y o f t h e a r e a was d e v e l o p e d b e f o r e Semiahmoo? t i m e (>62,000 r a d i o c a r b o n y r . B .P . ) and has r e m a i n e d b a s i c a l l y t h e same s i n c e t h e n . L a r g e g r a v e l r e s e r v e s o c c u r i n t h e a r e a , many o f them b u r i e d i n u p l a n d s and i n t h e s e d i m e n t f i l l o c c u p y i n g t h e l o w e r C o q u i t l a m R i v e r v a l l e y . Ou twash g r a v e l s a r e t h e most e x t e n s i v e o f t h e f o u r t y p e s f o u n d i n t h e a r e a and Va shon o u t w a s h i s t h e most commonly m i n e d . B u r i e d l a n d s c a p e s make p i t r un r e s e r v e e s t i m a t i o n v e r y d i f f i c u l t , and m u n i c i p a l z o n i n g r e g u l a t i o n s a r e p h a s i n g o u t g r a v e l o p e r a t i o n s and c o v e r i n g v a l u a b l e r e s e r v e s w i t h u r b a n and i n d u s t r i a l s u b -d i v i s i o n s . V . TABLE OF CONTENTS Page ABSTRACT i i i TABLE OF CONTENTS V L I ST OF TABLES v i i L I ST OF FIGURES AND PLATES v i i i ACKNOWLEDGMENTS x i i CHAPTER ONE: INTRODUCTION T A. G e n e r a l 1 B. P r e v i o u s Work 5 CHAPTER TWO: MARY H ILL 7 A. I n t r o d u c t i o n 7 B. M e a s u r e d S e c t i o n s 9 C. D i a g r a m m a t i c C o m p o s i t e S e c t i o n s 9 D. Q u a t e r n a r y H i s t o r y and C o n c l u s i o n s 21 CHAPTER THREE: LOWER COQUITLAM VALLEY 29 A. I n t r o d u c t i o n 29 B. M e a s u r e d S e c t i o n s 32 C. D i a g r a m m a t i c C o m p o s i t e S e c t i o n s 32 D. Q u a t e r n a r y H i s t o r y and C o n c l u s i o n s 38 CHAPTER FOUR: PORT MOODY DISPOSAL S ITE 45 A. In t r od uc t i o n 45 B. M e a s u r e d S e c t i o n s 46 C. D i a g r a m m a t i c C o m p o s i t e S e c t i o n 46 D. Q u a t e r n a r y H i s t o r y and C o n c l u s i o n s 46 CHAPTER F I V E : QUATERNARY STRATIGRAPHY 54 A. C o r r e l a t i o n o f S e d i m e n t U n i t s 54 B. C o m p o s i t e S e c t i o n and D e s c r i p t i o n o f L i t h o s t r a t i - 58 g r a p h i c U n i t s C. T i l l and G l a c i o m a r i n e D e p o s i t s 54 CHAPTER S I X : QUATERNARY HISTORY 73 A. F r a s e r L o w l a n d 73 B. C o q u i t l a m - P o r t Moody A r e a 74 CHAPTER SEVEN: ENGINEERING AND ENVIRONMENTAL GEOLOGY 86 A. C o n s t r u c t i o n M a t e r i a l s 86 B. F o u n d a t i o n M a t e r i a l s and D r a i n a g e 93 C. Sewage D i s p o s a l 97 v i . Page D. F l o o d C o n t r o l 98 E. S l i d e s and W a s h o u t s 98 CHAPTER E IGHT: CONCLUSIONS 101 A . Q u a t e r n a r y G e o l o g y 101 B. E n g i n e e r i n g and E n v i r o n m e n t a l G e o l o g y 103 C. R e c o m m e n d a t i o n s f o r F u r t h e r S t u d y 105 REFERENCES CITED 107 APPENDICES 110 1 R a d i o c a r b o n D a t e s i n 2 , P e b b l e P r o v e n a n c e A n a l y s e s and L o c a l i t i e s 112 3 S t e r e o g r a m s and L o c a l i t i e s o f G l a c i a l D i a m i c t o n 113 P e b b l e F a b r i c A n a l y s e s k S e d i m e n t Samp le L o c a l i t i e s 114 V I1 L I ST OF TABLES C a p t i o n Page I. G r a v e l P i t O p e r a t i o n s on t h e West Bank o f t h e 30 Lower C o q u i t l a m R i v e r V a l l e y I I . C o r r e l a t i o n o f L i t h o s t r a t i g r a p h i c U n i t s 55 I I I . F o u n d a t i o n M a t e r i a l s and D r a i n a g e , 96 C o q u i1 1 a m - P o r t Moody A r e a , B.C. v i i i . L I ST OF FIGURES AND PLATES Cap t i o n F i g . 1. I ndex and G r a v e l P i t L o c a t i o n Maps w i t h G e o l o g i c a l C o n t a c t s . 2. M e a s u r e d S t r a t i g r a p h i c S e c t i o n s , Mary H i l l G r a v e l P i t , P o r t C o q u i t l a m , B.C. 3. D i a g r a m m a t i c C r o s s S e c t i o n s : Mary H i l l G r a v e l P i t , P o r t C o q u i t l a m , B.C. k. D e t a i l e d D i a g r a m m a t i c C r o s s S e c t i o n i n G u l l y a t M e a s u r e d S e c t i o n B. R e s u I t s o f Some H i l l G r a v e l P i t P e b b l e F a b r i c s : F i e l d Work Done i n Mary A, G l a c i a l D i a m i c t o n B, P a l e o c u r r e n t D a t a : C, P e b b l e P r o v e n a n c e ; D, R e g i o n a l G e o l o g y S how ing f o r P e b b l e s i n C. G e n e r a l i z e d S o u r c e A r e a s Page 2 10 PockeJ^on back cover <Ubif-,p-> 20 23 6. M e a s u r e d S t r a t i g r a p h i c S e c t i o n s i n t h e 33 West Bank o f t h e Lower C o q u i t l a m V a l l e y , B .C. 7. B l o c k D i a g r a m , West S l o p e o f t h e Lower 34 C o q u i t l a m R i v e r V a l l e y , B r i t i s h C o l u m b i a . 8. R e s u l t s o f Some F i e l d Wrok Done i n t h e 39 Lower C o q u i t l a m R i v e r V a l l e y G r a v e l P i t s : A , G l a c i a l D i a m i c t o n P e b b l e F a b r i c s ; B, P a l e o c u r r e n t D a t a ; C, P e b b l e P r o v e n a n c e ; D, G e n e r a l i z e d R e g i o n a l G e o l o g y Show ing S o u r c e A r e a s f o r P e b b l e s i n C. 9. H y p o t h e t i c a l F e n c e D i a g r a m , Lower C o q u i t - 43a lam V a l l e y , B.C. 10. M e a s u r e d S t r a t i g r a p h i c S e c t i o n s a t t h e 47 P o r t Moody D i s p o s a l S i t e : A, S e c t i o n D e s c r i p t i o n s , B, S e d i m e n t Samp le L o c a t i o n s . 11 . D i a g r a m m a t i c C o m p o s i t e S e c t i o n , P o r t Moody 48 D i s p o s a l S i t e , P o r t Moody , B r i t i s h C o l u m b i a . 12. R e s u l t s o f Some F i e l d Work Done a t t h e 50 P o r t Moody D i s p o s a l S i t e : A, G l a c i a l D i a m i c t o n P e b b l e F a b r i c s ; B, P a l e o c u r r e n t D a t a ; C, P e b b l e P r o v e n a n c e ; D, G e n e r a l i z e d R e g i o n a l G e o l o g y S how ing S o u r c e A r e a s f o r P e b b l e s i n C . C a p t i o n 13- H y p o t h e t i c a l R e c o n s t r u c t i o n o f P a r t s o f H i l l D e v e l o p e d D u r i n g Q u a t e r n a r y T ime Near P o r t Moody , B r i t i s h C o l u m b i a . ]k. H y p o t h e t i c a l Q u a t e r n a r y F e n c e D i a g r a m : Coq u i. 11 am-Po r t Moody A r e a , B r i t i s h C o l u m b i a . P l a t e I : F i g s . 15"20 1 5 - S u p r a 1 i t t o r a 1 l a g g r a v e l g r a d i n g downward i n t o p l a t y Va shon l o d g e m e n t t i l l , Mary H i l l . 16. S h e l l c a s t f r o m s u p r a 1 i t t o r a 1 l a g g r a v e l i n F i g . 1 5 -17- F o r e s e t and t o p s e t bedded C a p i l a n o r a i s e d d e l t a i c s and and g r a v e l , C o q u i t l a m v a l l e y . 18. F o s s i 1 i f e r o u s m a r i n e c l a y e y s i l t , C o q u i t l a m va1 l e y . 1 9 . B l o c k y C a p i l a n o g l a c i o m a r i n e s t o n y c l a y e y s i l t o v e r l y i n g p l a t y V a s h o n t i l l , Mary H i l l . 20. C o m p a c t , b o u l d e r y V a s h o n l o d g e m e n t t i l l , Ma ry H i l l . P l a t e 2: F i g s . 21-26 21. P o l i s h e d , g r o o v e d , s t r i a t e d , and c h a t t e r -marked g r a n i t i c e r r a t i c r e s t i n g on Va shon t i l l , Mary H i l l . 22. F o r e s e t bedded Va shon o u t w a s h s andy g r a v e l , Ma r y H i l l . 23. C o n t o r t e d i c e c o n t a c t Va shon s a n d , g r a v e l , and f l o w t i l l , C o q u i t l a m v a l l e y . 2h. C r o s s - b e d d e d Quad ra Sand ( l a r g e s c a l e ) , Ma ry H i l l . 25. C r o s s - b e d d e d Quad ra Sand ( s m a l l s c a l e ) , Mary H i l l . 26. T h i n p e a t l a y e r o v e r l y i n g Semiahmoo? s t o n y s i l t s , Mary H i l l . P l a t e 3: F i g s . 27"32 27. T h i n l y bedded Q u a d r a Sand u n d e r l y i n g Va shon D r i f t , C o q u i t l a m v a l l e y . X. C a p t i o n Page 28. Load c a s t s , b a l l and p i l l o w s t r u c t u r e s , and c o n v o l u t e d b e d d i n g i n s i l t y f i n e sand i n F i g . 27 . 29- M a s s i v e s t o n y C o q u i t l a m D r i f t , Mary H i l l . 30. S h a r p a n g u l a r c o n t a c t : C o q u i t l a m D r i f t o v e r l a i n by Quad ra Sand and u n d e r l a i n by s a n d , e i t h e r Quad ra o f p a r t o f t h e C o w i c h a n Head F o r m a t i o n , Mary H i l l . 3 1 . C o w i c h a n Head f l u v i a l g r a v e l and sand u n c o n f o r m a b 1 y o v e r l y i n g C o w i c h a n Head? d e n s e s t o n y o r g a n i c c o l l u v i u m , M a r y H i l l . 32. C o w i c h a n Head? s t o n y o r g a n i c c o l l u v i u m , Mary H i1 1 . P l a t e k: F i g s . 33-38 68 33- C o w i c h a n Head? w o o d - r i c h o r g a n i c s i l t l a y e r ( c e n t r e o f p h o t o ) b e t w e e n Quad ra ? l a m i n a t e d s i l t y f i n e sand ( a b o v e ) and Semiahmoo? t i l l and o u t w a s h g r a v e l ( b e l o w ) , P o r t Moody , B.C. 34. B u r i e d l a n d s c a p e : C o w i c h a n Head p e a t l a y e r c o n t a i n i n g a f o s s i l s p r u c e s tump ( b e l o w b o u l d e r i n c e n t r e o f p h o t o ) a b u t s a g a i n s t t h e s l o p e f o r m e d on C o w i c h a n Head? s t o n y o r g a n i c c o l -. 1.u v i urn , Ma r y H i l l . 35- F o s s i l s p r u c e s tump i n p e a t l a y e r i n F i g . 34. 36. Semiahmoo? D r i f t , C o q u i t l a m v a l l e y . 37- Semiahmoo? g l a c i o m a r i n e ? s t o n y c l a y e y s i l t i n F i g . 36. 38. . Semiahmoo? ,p1 a t y l o d g e m e n t t i l l i n F i g . 36. P l a t e 5: F i g s . 33-kh 39- Semiahmoo? g 1 a c i o 1 a c u s t r i n e r h y t h m i c a l l y l a m i n a t e d s t o n y s i l t , Mary H i l l . 4 0 . Semiahmoo? p r o g l a c i a l s a n d , P o r t Moody. 4 1 . H i g h b u r y ? f l u v i a l t h i n l y bedded s a n d , s i l t , and m i n o r g r a v e l b e t w e e n Semiahmoo? o u t w a s h g r a v e l and sand ( a b o v e ) and W e s t l y n n ? o u t w a s h ? g r a v e l ( b e l o w ) , C o q u i t l a m v a l l e y . 69 x i . C a p t i o n Page 4 2 . R i p p l e d , t h i n l y bedded H i g h b u r y ? s and i n F i g . 41 . 4 3 . C o n t a c t : H i g h b u r y ? t h i n l y bedded s a n d , s i l t , and m i n o r g r a v e l u n c o n f o r m a b 1 y o v e r l y i n g W e s t l y n n ? o u t w a s h ? g r a v e l , C o q u i t l a m v a l l e y . 4 4 . S e m i - i m p e r v i o u s W e s t l y n n ? o u t w a s h ? c o a r s e g r a v e l , C o q u i t l a m v a l l e y . 45 . . M a t r i x G r a i n S i z e D i s t r i b u t i o n o f T i l l and G l a c i o m a r i n e D e p o s i t s : A, P l o t o f A n a l y s e s B, A r e a s o f G r a i n S i z e D i s t r i b u t i o n . 4 6 . I n f e r r e d I ce Movement D i r e c t i o n s f r o m P e b b l e F a b r i c s i n E x p o s e d P l e i s t o c e n e G l a c i a l D i a m i c t o n s : C o q u i1 1 a m - P o r t Moody A r e a , B r i t i s h C o l u m b i a . 4 7 . P a l e o c u r r e n t D i r e c t i o n s i n E x p o s e d P l e i s t o -c e n e Sand and G r a v e l : C o q u i1 1 a m - P o r t Moody A r e a , B r i t i s h C o l u m b i a . 4 8 . P e b b l e P r o v e n a n c e o f E x p o s e d P l e i s t o c e n e S e d i m e n t s : C o q u i1 1 a m - P o r t Moody A r e a , B r i t i s h C o l u m b i a . 4 9 . G r a i n S i z e D i s t r i b u t i o n o f P l e i s t o c e n e G r a v e l D e p o s i t s : C o q u i1 1 a m - P o r t Moody A r e a , B r i t i s h C o l u m b i a . A, G l a c i a l Outwash B, R a i s e d D e l t a and A l l u v i a l F l o o d P l a i n C, S u p r a l i t t o r a l D, A r e a s o f G r a i n S i z e D i s t r i b u t i o n . 71 75 x i i . ACKNOWLEDGMENTS The w r i t e r i s i n d e b t e d t o J . E. A r m s t r o n g , s e n i o r r e s e a r c h s c i e n t i s t o f t h e G . S . C . , T e r r a i n S c i e n c e s D i v i s i o n , V a n c o u v e r , f o r h i s e n c o u r a g e m e n t and s u p p o r t i n s u p e r v i s i n g f i e l d w o r k , f o r p r o v i d i n g t h e t h e s i s t o p i c , f o r many s t i m u l a t i n g d i s c u s s i o n s , b o t h g e o l o g i c a l and o t h e r w i s e , and f o r c r i t i c a l l y r e a d i n g t h e m a n u s c r i p t ; t o W. H. M a t h e w s , p r o f e s s o r o f G e o l o g i c a l S c i e n c e s , and t h e w r i t e r ' s t h e s i s a d v i s o r a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , f o r f i n a n c i a l s u p p o r t i n t h e t h e s i s p r e p a r a t i o n , f o r many e n l i g h t e n i n g c o n v e r s a t i o n s , and f o r c r i t i c a l l y r e a d i n g t h e m a n u s c r i p t ; t o W. A . B l a k e , J r . , f o r r a d i o c a r b o n d a t e s ; and t o J . V. M a t t h e w s f o r i n s e c t s t u d i e s on o r g a n i c m a t e r i a l s s u b m i t t e d f r o m t h e t h e s i s a r e a , b o t h o f t h e G . S . C . T e r r a i n S c i e n c e s D i v i s i o n , O t t a w a ; and t o t h e G . S . C . f o r p r o v i d i n g t h e w r i t e r w i t h w i n t e r and summer e m p l o y m e n t w h i l e t h e t h e s i s was b e i n g p r e p a r e d . G r a t i t u d e i s a l s o e x t e n d e d t o W. C. B a r n e s , a s s o c i a t e p r o f e s s o r i n t h e D e p a r t m e n t o f G e o l o g i c a l S c i e n c e s , U . B . C . , f o r p r o v i d i n g l a b o r a t o r y f a c i l i t i e s t o t h e w r i t e r ; t o R. E. K u c e r a and J . L. R a u , a l s o i n t h e D e p a r t m e n t o f G e o l o g i c a l S c i e n c e s , U . B . C . , f o r c r i t i c a l l y r e a d i n g t h e t h e s i s ; t o D. M. Mark o f t h e G e o g r a p h y D e p a r t m e n t , S imon F r a s e r U n i v e r -s i t y , f o r c o m p u t e r a n a l y s e s o f t h e w r i t e r ' s p e b b l e f a b r i c d a t a ; t o G. R. Dumas o f t h e G . S . C . f o r d r a f t i n g ; t o R. H. M a c N e i l l , p r o f e s s o r i n t h e G e o l o g y D e p a r t m e n t a t A c a d i a U n i v e r s i t y , u n d e r whose d i r e c t i o n t h e t h e s i s was s t a r t e d , f o r c r i t i c a l l y r e a d i n g t h e m a n u s c r i p t ; t o E. F r e u n d o f C o n s t r u c t i o n A g g r e g a t e s L t d . f o r i n f o r m a t i o n a b o u t and g r a n t i n g a c c e s s t o t h e Mary H i l l g r a v e l p i t ; t o J . M i n g r o v e , head f o r e m a n , who has w o r k e d a t t h e Mary H i l l g r a v e l p i t s i n c e 1939, for r e l a t i n g i t s h i s t o r y o f owner s h i p and o p e r a t i o n t o t h e w r i t e r ; t o B. Thomas , P. E n g . , and t h e D i s t r i c t o f C o q u i t l a m E n g i n e e r i n g D e p a r t m e n t f o r i n f o r m -a t i o n and maps c o n c e r n i n g t h e C o q u i t l a m v a l l e y p i t s ; and t o M r s . W. D. H i c o c k , B . A . , B . E d . , t h e w r i t e r ' s m o t h e r , f o r t y p i n g t h e m a n u s c r i p t . x i v . D ED I CAT I ON D e d i c a t e d t o F r a n whose p a t i e n c e and u n d e r s t a n d i n g i n r e a l i z i n g t h e c o m p l e t i o n o f t h i s work was s u r p a s s e d o n l y by h e r e n c o u r a g e m e n t . CHAPTER ONE: INTRODUCTION G e n e r a l The C o q u i11 a m - P o r t Moody a r e a i s l o c a t e d 20 km e a s t o f t h e c i t y o f V a n c o u v e r and i s bounded a p p r o x i m a t e l y by l a t i t u d e s H 9 ° 1 3 ' and 4 9 ° 2 0 ' N , and l o n g i t u d e s 1 2 2 ° 4 5 ' and 1 2 2 ° 5 3 ' W ( F i g . 1) I t l i e s a t t h e s o u t h e r n end o f t h e B.C. C o a s t M o u n t a i n s and c o n t a i n s t h e g1 a c i e r - c a r v e d C o q u i t l a m v a l l e y w h i c h open s o n t o a f l a t - l y i n g a r e a u n d e r l a i n by s e d i m e n t s d e p o s i t e d by t h e F r a s e r , P i t t , and C o q u i t l a m R i v e r s . T h i s a r e a s u r r o u n d s Mary H i l l and i s b o r d e r e d by u p l a n d s t o t h e n o r t h and w e s t . D u r i n g t h e t i m e o f f i e l d w o r k , 1 9 7 ^ - 7 6 , t h e w r i t e r was e m p l o y e d w i t h J . E. A r m s t r o n g o f t h e G e o l o g i c a l S u r v e y o f Canada ( G . S . C . ) t o a s s i s t h im i n t h e r e v a l u a t i o n o f t e r r a i n i n v e n t o r y maps and i n Q u a t e r n a r y s t r a t i g r a p h i c s t u d i e s o f t h e F r a s e r L o w l a n d , B.C. Fo r t h i s t h e s i s t h e w r i t e r u n d e r t o o k t h e p r o b l e m o f w o r k i n g o u t i n d e t a i l t h e s t r a t i g r a p h y and Q u a t e r -n a r y h i s t o r y o f t h e C o q u i11 a m - P o r t Moody a r e a , w h e r e p r e - V a s h o n P l e i s t o c e n e s e d i m e n t s a r e b e s t e x p o s e d i n t h e F r a s e r L o w l a n d . Soon a f t e r work on t h e t h e s i s b e g a n , i t was r e a l i z e d t h a t t h e Coqu i11 a m - P o r t Moody a r e a c o n t a i n s some o f t h e most s t r a t i g r a p h -i c a l l y c o m p l e x Q u a t e r n a r y d e p o s i t s i n t h e w o r l d , whose h i s t o r y i n v o l v e d r e p e a t e d g l a c i a t i o n s , s e a - l e v e l c h a n g e s , and t h e f o r m -a t i o n o f n o n g l a c i a l o r g a n i c s e d i m e n t s . T h i s s t u d y i s b a s ed on d e t a i l e d i n v e s t i g a t i o n s o f e i g h t g r a v e l p i t s i n t h e a r e a i n w h i c h s t r a t i g r a p h i c s e c t i o n s o f P l e i s t o c e n e s e d i m e n t s a r e w e l l e x p o s e d and i s an a t t e m p t t o c o r r e l a t e t h e s e s e c t i o n s and g a i n an u n d e r s t a n d i n g o f t h e 2. 122°53( 122°45' Figure 1 INDEX AND GRAVEL PIT LOCATION MAPS WITH GEOLOGICAL CONTACTS (based on Armstrong, i n prep.). L E G E N D for F i g u r e 1 Quaternary Deposits Holocene Holocene Sediments 13 Slopewash 12 Peat—bog, swamp, and shallow lake deposits. 11 Fraser River sediments—floodplain, channel, and estuarine s i l t , clay, and minor sand. 10 Lowland stream deposits— channel and floodplain s i l t , clay, fine sand and minor gravel; may in part be deltaic deposits. 9 Mountain stream deposits—channel and deltaic sand and gravel with minor s i l t and clay. Holocene and Pleisocene 8 Sand—floodplain, channel, and slopewash sand (Holocene); may in part be reworked marine l i t t o r a l and beach sand (Pleistocene) Pleistocene Capilano Sediments 7 Raised marine beach, spit, bar, and lag veneer sand and gravel. 6 Raised i n t e r t i d a l and beach sand. 5 Raised deltaic and channel f i l l sand and gravel. Vashon D r i f t and Capilano Sediments 4 Glaciomarine stony s i l t loam and g l a c i a l deposits including t i l l , stony laminated s i l t s , and substratified g l a c i o f l u v i a l sand and gravel. Vashon-Drift 3 T i l l , stony laminated s i l t s and substratified g l a c i o f l u v i a l sand and gravel. Pre-Vashon Sediments 2 Sand, gravel, s i l t , clay, and t i l l underlying Vashon D r i f t . Bedrock—granitic and associated rock types at or near the surface. Commonly overlain by t i l l , s i l t , and outwash sand and gravel. Geological contact /».../, Gravel P i t studied Gravel pits studied: A Mary H i l l B Greater Vancouver Sewerage and Drainage D i s t r i c t C Allard D Kask Bros. E Johnson F S and S and Columbia B i t u l i t h i c G Jack Cewe Ltd. Mesozoic H Port Moody sanitary l a n d f i l l d e p b s i t i o n a 1 p r o c e s s e s and m e c h a n i s m s o p e r a t i n g i n t h e a r e a d u r i n g Q u a t e r n a r y t i m e . T h i s s h o u l d h e l p i n t h e g e o l o g i c a l i n t e r p r e t a t i o n o f a d j a c e n t a r e a s and p e r h a p s i n d i s c o v e r i n g more s o u r c e s o f g r a n u l a r a g g r e g a t e i n t h e G r e a t e r V a n c o u v e r a r e a . I n v e s t i g a t i o n s by t h e w r i t e r and a s s o c i a t e s have i n c l u d e d r a d i o c a r b o n d a t i n g o r o r g a n i c m a t e r i a l s c o l l e c t e d f r o m t h e s e d i m e n t s ; d e t e r m i n a t i o n o f d i r e c t i o n s o f p a l e o s t r e a m f l o w i n t h e sand and g r a v e l u n i t s f r o m c r o s s - b e d d i n g , f o r e s e t b e d d i n g , and i m b r i c a t i o n ; s t o n e f a b r i c s t u d i e s o f g l a c i a l d i a m i c t o n s t o d e t e r m i n e d i r e c t i o n s o f i c e f l o w i n t h e a r e a ; g r a i n s i z e and b a s i c m i n e r a 1 o g i c a 1 a n a l y s e s o f t h e s e d i m e n t s ; and i n s e c t s t u d i e s o f some o r g a n i c - b e a r i n g s e d i m e n t s . A n a l y s e s o f p e b b l e s a m p l e s and c a l c u l a t i o n s o f p r o v e n a n c e a r e g i v e n i n A p p e n d i x 2 P a l e o c u r r e n t d i r e c t i o n s b a s e d on s m a l l s c a l e c r o s s - b e d s ( p a l e o c h a n n e l w i d t h s up t o 5 cm) w e r e d e t e r m i n e d by d i g g i n g i n t o a s e d i m e n t f a c e and s c r a p i n g o u t a h o r i z o n t a l s u r f a c e t o f o r m a s t e p . P a l e o c h a n n e l a x e s we re t h e n m e a s u r e d i n p l a n v i e w , i n t h e c o n c a v e d i r e c t i o n o f t h e t r o u g h s ( F i g . 2 5 ) . L a r g e s c a l e c r o s s - b e d s ( p a l e o c h a n n e l w i d t h s 5 cm t o 5 m; F i g . 2k) w e r e m e a s u r e d w h e r e c r o s s s e c t i o n s n o r m a l t o p a l e o c h a n n e l a x e s c o u l d be s e e n . P e b b l e f a b r i c a n a l y s e s we re done by m e a s u r i n g t h e d i r e c t i o n and p l u n g e o f p e b b l e l o n g a x e s as t h e y o c c u r r e d i n u n d i s t u r b e d e x p o s u r e s o f g l a c i a l d i a m i c t o n s . I n d i v i d u a l s t r a t i g r a p h i c s e c t i o n s i n e a c h g r a v e l p i t a r e d e s c r i b e d and t h e n c o r r e l a t e d and g r a p h i c a l l y i l l u s t r a t e d by d i a g r a m m a t i c c r o s s s e c t i o n s f o r e a c h p i t . F i n a l l y t h e s t r a t i -g r a p h y o f t h e p i t s a r e c o r r e l a t e d w i t h one a n o t h e r and c r o s s s e c t i o n s c o n s t r u c t e d t h r o u g h t h e w h o l e map a r e a . R e c o n s t r u c -t i o n o f t h e Q u a t e r n a r y h i s t o r y o f t h e a r e a i s b a s ed on s e c t i o n d e s c r i p t i o n s and c o n c l u s i o n s d rawn f r o m t h e m . P h o t o g r a p h s o f t h e s e d i m e n t u n i t s a r e i n c l u d e d i n C h a p t e r F i v e bu t a r e r e f e r -r e d t o t h r o u g h o u t t h e t h e s i s . The s o u t h s l o p e o f Mary H i l l on t h e F r a s e r R i v e r was t h e s i t e o f t h e f i r s t g r a v e l p i t i n t h e a r e a i n 1 928 , and i t was t h e o n l y p i t u n t i l Deeks Sand and G r a v e l Co. o p e n e d a p i t n o r t h o f L o u g h e e d H i ghway (No. 7) i n t h e e a r l y 1 9 4 0 ' s . The g e n e r a l p u b l i c removed a g g r e g a t e f o r t h e i r own u se f r o m o t h e r e x c a v a -t i o n s i n Crown Land i n t h a t a r e a u n t i l t h e D i s t r i c t o f C o q u i t l a m t o o k c o n t r o l o f t h e l a n d use i n t h e v a l l e y i n t h e mid 1960 1 s . S i n c e t h e n c o m p a n i e s and t h e m u n i c i p a l i t y have o p e n e d and e x t e n d e d g r a v e l p i t s i n t h e C o q u i t l a m v a l l e y , m a i n l y f o r t h e s a l e o f g r a n u l a r a g g r e g a t e , u n d e r s t r i c t b y - l a w s impo sed by t h e D i s t r i c t . E x c a v a t i o n s a t t h e P o r t Moody s a n i t a r y l a n d f i l l s i t e we re begun by S c o t t B r o s , i n 1963 f o r s and s a l e s and i n t h e mid 1960 1 s by t h e C i t y o f P o r t Moody f o r g a r b a g e d i s p o s a l . P r e v i o u s Work The e a r l i e s t wo rk on s u r f i c i a l g e o l o g y done i n t h e a r e a was by Bu rwa sh ( 1918 ) who mapped t h e s u r f i c i a l and b e d r o c k g e o l o g y o f t h e G r e a t e r V a n c o u v e r a r e a ( e a s t t o Haney) and Howe S o u n d . J o h n s t o n ( 1 9 2 1 , 1923) p u b l i s h e d t h e f i r s t map o f s u r f i c i a l d e p o s i t s i n t h e V a n c o u v e r a r e a w h i l e s t u d y i n g t h e s e d i m e n t a t i o n o f t h e F r a s e r R i v e r d e l t a . No f u r t h e r g e o l o g i c a l s t u d i e s we re p u b l i s h e d on t h e C o q u i 1 1 a m - P o r t Moody a r e a u n t i l A r m s t r o n g (1953 ) w r o t e a p a p e r on t h e g e o l o g y o f s and and g r a v e l d e p o s i t s i n t h e Lower F r a s e r V a l l e y , and A r m s t r o n g and Brown (1954 ) p u b l i s h e d a p a p e r on t h e g l a c i o m a r i n e d e p o s i t s f o u n d i n t h e same a r e a . R o d d i c k and A r m s t r o n g (1956) p r o d u c e d a p r e l i m i n a r y b e d r o c k map o f t h e V a n c o u v e r a r e a ( e a s t h a l f ) s h o w i n g t h e d i s t r i b u t i o n o f Q u a t e r -n a r y d e p o s i t s i n g e n e r a l . T h i s was l a t e r r e p l a c e d by a r e v i s e d map and r e p o r t ( R o d d i c k , 1 9 6 5 ) - A r m s t r o n g (1957 ) c o m p l e t e d a p r e l i m i n a r y r e p o r t and map ( 1 : 6 3 , 3 6 0 s c a l e ) on t h e s u r f i c i a l g e o l o g y o f t h e New W e s t m i n s t e r a r e a , and i n 1961 A r m s t r o n g w r o t e a p a p e r on t h e s o i l s o f t h e c o a s t a l a r e a o f s o u t h w e s t B r i t i s h C o l u m b i a f r o m a g e o l o g i c a l v i e w p o i n t . In a f i e l d t r i p g u i d e b o o k A r m s t r o n g (1965 ) d e s c r i b e d t h e e x p o s u r e a t Mary H i l l , and i n a c l a s s i c j o i n t p a p e r , he d o c u m e n t e d t h e P l e i s t o c e n e s t r a t i g r a p h y and c h r o n o l o g y i n s o u t h w e s t e r n B.C. and n o r t h -w e s t e r n W a s h i n g t o n ( A r m s t r o n g , e t a l . , 1 9 6 5 ) . Learn ing ( 1968 ) g e n e r a l l y d e s c r i b e d t h e o p e r a t i o n s and d e p o s i t s on t h e g r a v e l p i t s s t u d i e d i n t h i s t h e s i s i n a r e p o r t on t h e sand and g r a v e l i n t h e S t r a i t o f G e o r g i a a r e a . R e c e n t l y A r m s t r o n g (1975) r e p o r t e d on s t r a t i g r a p h i c s t u d i e s and r e v a l u a t i o n o f h i s p r e l i m i n a r y s u r f i c i a l g e o l o g y map s h e e t s i n t h e F r a s e r L o w l a n d and i n t h a t y e a r b r i e f l y d e s c r i b e d t h e Quat e r n a r y g e o l o g y o f t h e F r a s e r L o w l a n d f o r a f i e l d t r i p g u i d e b o o k , A r m s t r o n g and H i c o c k (1975 ) i n v e s t i g a t e d b u r i e d l a n d s c a p e s i n Mary H i l l , and Rowe (1975 ) w r o t e .an u n p u b l i s h e d B . S c . t h e s i s on t h e Mary H i l l g r a v e l p i t . A r m s t r o n g and H i c o c k (1976 ) d e s c r i b e d Q u a t e r n a r y - m u l t i p l e v a l l e y d e v e l o p m e n t i n t h e l o w e r C o q u i t l a m v a l l e y and A r m s t r o n g and C l a g u e ( i n p r e s s ) have r e d e f i n e d t h e Quad ra s e d i m e n t s , u s i n g Mary H i l l as a p a r a s t r a t o t y p e s e c t i o n . CHAPTER TWO: MARY H ILL I n t r o d u c t i o n Mary H i l l g r a v e l p i t was i n 1975 t h e l a r g e s t i n B r i t i s h C o l u m b i a . I t was e x c a v a t e d i n t o t h e s o u t h e r n s l o p e o f Ma ry H i l l , C i t y o f P o r t C o q u i t l a m , a s m a l l r o u n d e d u p l a n d s u r r o u n d e d by t h e w i d e , f1 a t - b o t t o m e d v a l l e y s o f t h e F r a s e r , P i t t , and C o q u i t l a m R i v e r s ( F i g . 1). Mary H i l l was a p p r o x i m a t e l y 3 km l o n g , 1.5 km w i d e , and 95 m i n e l e v a t i o n . When f i e l d wo rk was done f o r t h i s t h e s i s , t h e p i t e x t e n d e d 1200 m n o r t h o f t h e F r a s e r R i v e r w i t h an a v e r a g e w i d t h o f 750 m and c o n t a i n e d some o f t h e b e s t e x p o s e d P l e i s t o c e n e s t r a t i g r a p h i c s e c t i o n s , common ly i n t h r e e d i m e n s i o n s , i n t h e F r a s e r L o w l a n d ( F r o n t s p i e c e ) . Much o f t h e p i t had been f i l l e d i n bu t r e m a i n i n g e x p o s u r e s r e v e a l e d t h e c o m p l e x n a t u r e o f t h e s e d i m e n t c o n t a c t s . T h i s c o m p l e x s t r a t i g r a p h y p r o b a b l y o c c u r s i n P l e i s t o c e n e u p l a n d s t h r o u g h o u t t h e F r a s e r L o w l a n d and i s e x e m p l i f i e d by b u r i e d l a n d s c a p e s i n c o m p o s i t e h i l l s . G r a v e l e x c a v a t i o n was s t a r t e d a t Ma r y H i l l i n 1928 by t h e F r e s h w a t e r Sand and G r a v e l Co . ( G i l l e y B r o s . ) w h i c h h y d r a u l i c -a l l y m ined t h e s o u t h e r n „ s 1 o p e by pump ing F r a s e r R i v e r w a t e r t h r o u g h s i x - i n c h p i p e l i n e s s u s p e n d e d f r o m a d e r r i c k on a b a r g e . L a t e r a s t e a m - d r i v e n i m m o b i l e d r e d g e , mounted on p i l i n g s , u sed c l a m b u c k e t s t o s c o o p up g r a v e l t h a t was m o n i t o r e d f r o m t h e h i l l s i d e and c a u g h t b e h i n d a g a t e a t t h e r i v e r l e v e l . As t h e m o n i t o r e d f a c e was e x c a v a t e d f u r t h e r i n t o t h e h i l l , t h e g r a v e l had t o be t r a n s p o r t e d t o t h e b u c k e t s by c a r t s on t r a c k s . The b u c k e t s t h e n dumped t h e g r a v e l i n t o h o p p e r s f e e d i n g t h e s o r t i n g 8. a p p a r a t u s on t h e b a r g e . G i l l e y B r o s , o p e r a t e d t h i s way u n t i l 1930 when a wooden s e p a r a t i n g p l a n t was c o n s t r u c t e d on s h o r e . In 1946 a r o a d was c o n s t r u c t e d a l o n g t h e b a s e o f t h e h i l l and by 1950 t r u c k s w e r e u sed t o h a u l t h e m o n i t o r e d g r a v e l t o a h o p p e r w h i c h f e d a c o n v e y o r b e l t c a r r y i n g m a t e V i a l t o t h e s e p a r a t i n g p l a n t . A new s t e e l s e p a r a t i n g p l a n t and c o n c r e t e s t o r a g e s i l o s we re b u i l t a t t h e b a s e o f t h e h i l l i n 1 9 5 2 , and soon a f t e r h y d r a u l i c m i n i n g was r e p l a c e d by l a r g e d i e s e l s h o v e l s and t r u c k s . G i l l e y B r o s , a m a l g a m a t e d w i t h E v a n s , C o l e m a n , and Evans i n 1955 and soon a f t e r s o l d a l l t h e i r i n t e r e s t i n t h e p i t , m a k i n g t h e l a t t e r company s o l e o w n e r s . In 1958 Ocean Cement L t d . (now c o n t r o l l e d by Ge .n s t a r ) b o u g h t t h e p i t and o p e r a t e d i t t h r o u g h v a r i o u s s u b s i d i a r y c o m p a n i e s . The l a s t o f t h e s e was C o n s t r u c t i o n A g g r e g a t e s L t d . w h i c h o p e r a t e d t h e p i t f r o m 1970 u n t i l 1975 when i t was r e q u i r e d t o c l o s e b e c a u s e o f z o n i n g r e g u l a t i o n s impo sed by t h e C i t y o f P o r t C o q u i t l a m . The c i t y p l a n s t o have e n g i n e e r e d homes b u i l t on t h e s i t e . U n t i l I 960 t h e s e p a r a t i n g p l a n t c o u l d p r o c e s s o n l y s and and g r a v e l , bu t i n t h a t y e a r a new s t e e l s e p a r a t i n g t o w e r w i t h s c r u b b e r s and w a s h e r s was i n s t a l l e d t o p r o c e s s t i l l ( L e a r n i n g , 1 9 6 8 ) . F o r many y e a r s o n l y deep h o l e s i n s m a l l a r e a s w i t h i n t h e p i t we re m i n e d , o f t e n m a k i n g g r a v e l r e m o v a l d i f f i c u l t , and t h e p i t e x t e n d e d o n l y 200 m e t r e s n o r t h o f F r a s e r R i v e r i n 1965 -S i n c e t h e n much g r e a t e r a r e a s have been u n c o v e r e d and t h e p i t g r e a t l y e x p a n d e d t o t h e d i m e n s i o n s a t t h e t i m e o f c l o s u r e i n 1975 - S i n c e 1928 t h e p i t has s u p p l i e d o v e r 20 m i l l i o n m o f s a n d , g r a v e l , and c r u s h e d r o c k a t a p r e s e n t - d a y v a l u e o f a t l e a s t $20 m i l l i o n ( p i t r un m a t e r i a l o n l y , a t t h e s i t e ) t o t h e c o n s t r u c t i o n i n d u s t r y i n t h e G r e a t e r V a n c o u v e r a r e a . M e a s u r e d S e c t i o n s The b e s t e x p o s e d s e c t i o n s i n t h e p i t w h i c h we re m e a s u r e d w i t h a W a l l a c e and T i e r n a n a l t i m e t e r a r e shown i n F i g . 2. The m e a s u r e d s e c t i o n s l i e a l o n g f o u r c r o s s s e c t i o n l i n e s c h o s e n t o b e s t i l l u s t r a t e t h e s t r a t i g r a p h i c r e l a t i o n s h i p s b e t w e e n t h e s e d i m e n t u n i t s ( I n d e x Map, F i g . 2 ) . A d i a g r a m m a t i c f e n c e d i a g r a m i n c o r p o r a t i n g t h e m e a s u r e d s e c t i o n s i s shown l a t e r i n F i g . 3- F i e l d d a t a a r e p l o t t e d on e a c h s e c t i o n whe re t h e work was done and a r e c o d e d i n t h e l e g e n d t o s a v e s p a c e i n t h e t e x t Da ta a r e a l s o r e c o r d e d on s e p a r a t e maps u n d e r " Q u a t e r n a r y H i s t o r y and C o n c l u s i o n s " i n t h i s c h a p t e r o r i n t h e a p p e n d i c e s . D i a g r a m m a t i c C o m p o s i t e S e c t i o n s F i g . 3 i s a d i a g r a m m a t i c f e n c e d i a g r a m o f t h e s o u t h e r n h a l f o f Ma ry H i l l as i t p r o b a b l y a p p e a r e d b e f o r e e x c a v a t i o n . The m e a s u r e d s e c t i o n s o f F i g . 2 and t o p o g r a p h i c s u r f a c e a t t h e t i m e o f m a p p i n g a r e p l o t t e d on e a c h c r o s s s e c t i o n . G e o l o g i c a l c o n t a c t s shown by s o l i d l i n e s i n d i c a t e w h e r e i n f o r m a t i o n i s known f r o m o t h e r , l e s s w e l l e x p o s e d s e c t i o n s , and b r o k e n c o n t a c t s i n d i c a t e w h e r e i n f o r m a t i o n was e x t r a -p o l a t e d . D e s c r i p t i o n s o f t h e s e d i m e n t u n i t s i n F i g . 3 a r e g i v e n i n t h e l e g e n d ; h o w e v e r , a d d i t i o n a l i n f o r m a t i o n i s g i v e n b e l o w , commenc i ng w i t h t h e o l d e s t u n i t . U n i t 1, an u n d i f f e r e n t i a t e d g l a c i a l c o m p l e x , c o m p r i s e d o f l o d g e m e n t t i l l , g 1 a c i o f 1 u v i a 1 , g l a c i o m a r i n e , and g 1 a c i o 1 a c u s t -r i n e p h a s e s , was f o u n d i n m e a s u r e d s e c t i o n s B, D, M, and P, 10 80 60 40 H 20-1 , par, tf215°(at) HH61SD N18,GOO + (GSC 2194, WD)— WIMST'' KH59TL7' Pt " ^tf043° (no) MH27SD 27,000 + 490 (GSC 2263, WD) MH09ST 40,500 + 1700 (GSC 2167, WD) HH08ST h. xbl95°(la), 210°(ae) ct, U, par, contain* H claate; colluviim , 1*. dt, pr, ct, ponded mauoi^yPr MH29SD-tz3-«llty, la, h, rf>165c(a«),f This aection not aamplad. 60 H 2 C H I , at, par, x»200°(le) 'ct, xbl90°Ua) gr, pebble fabric 2336(aO; -a, in p.rt be ti l l . I , xb21S°(l.) 195°(ea) X *,Tm, Ptr v * Fe, tb, xb070°T(aa) Oil^' p, par ^d50°S, xb(la), f Thla aection not aanpled. H U 3 , 3 5 S D ' { G S C 2 2 1 7 > L N Y E MH31ST' \ P M . •Section X la not on tni* aection line; it occur• 120n aouth of aection J. pebble-cobble gravel, ~ pil5°HW, pr 60 20H pebble-cobble gravel, dlO SW, par •dl0°S, g, at, par •t, et, pr pr, pebble fabric (no)* C 27,400 + 420 (CSC 2107, WD) 2^8,200 + 200 (GSC 2139, WD) 29,600 + 200 [GSC 2140. PT) 26.200 + 3: (GSC 2191, WD)-J 40,200 +430 (GSC 2137, W D H containa organic material HH38TL MH39SD HH37GV HH33,35SD^  • P". tf231°(wk) • " a g, c, d0S°SE. . g, xb215°(la) 195 {••) •Pebble fabric froa Rove, 1975. ILboulder layer, pr L»d in allty fine aand , xb-d25°SSV. pi20°H, pr . r, xb215°(.a) LEVEL SAMPLE LOCATIONS: SECTIONS A, B.C A" r80 r-60 -40 r-20 80 -60 r-40 r-20 C" r80 H60 -40 r-20 40 H 20-rahell caata, blocky structure, Irideacent Mn-ataioed joint •urfacea, pr, pebble fabric 16S°(at) KH54TL JBT'"' P*r' t , 1 M ( w k ) TUg*-pebble-cobble gravel, pr M H 5 2 C M - J ^ " P R ' P E B B L E T A H T L C <NO> KH53GV •*^VP«bbl«-*'>l>ble gravel, par at. par 26,000 + 310 26,200 + (CSC 2277, WD),(CSC 219T, WD) MH17SD 40,200 + (GSC 2137, WD) pr, pebble fabric (no) ,pt-wd containa wd M, par, xb200"(le) Section deatroyed before •enpling ^•organic -bearing MH19SD A p t * f * SEA 100 L E G E N D 9 Till, in places overlain by thin mantle of supralittoral (wove washed) log grovel Gravel 1: ' ' J Sand EM sn. U|111U) Slony ctayey silt (massive-thought lo be glaciomarine) Glacial complex including: till, laminated irony silt, and fine sand t:::::::::j Layered peal ood sapropel sequence with interbedded, organic-bearing silty t^iJIM Stony cdluvial organic complex 18.600 * 190 Radiocarbon dote (GSC 2194, PTW0) i n y e o r s B- P" ^ ^date from peat or wood Lab. no-. Geological Survey of Canada METRES 0 100 horizontal scale 200 MH01SD GV ST TL GM MH-Mary Hill A Sample no.-sand Stony clayey silt (thought to be glaciomarine) Measured stratigraphic section h horizontally bedded tb thinly bedded In laminated xb cross bedded.paleoc (Is)-measurement taken fi (js)-measurement taken fi d dipping beds, dip and di recti f rippled bedding direction towards which sti large scale channel (channel v small scale channel (channel \ •dlh up to 5m) idth up to 5cm) g contains gravel interbeds and lenses g-pi, pr, etc. -cha rater is tie following the da m fnossive, uniform et contorted f faulted fs fissile p platy $ contains fossil shell fragments c contains detrital cool and pea st contains dispersed stones and pt thin fossil peat layer wd thin fossil wood layer pr pebbles and/or cobbli psr pebbles and/or cobbli pi pebbles and/or cobbli tf till (pebble) fabric analysis don (st) strong preferred pebble orientation (wk)weok preferred pebble orientati (no) no preferred pebble orientotion Fe sediment stained with iron oxide MH65GV MB64 MH66GV » N ITL-ferfp, par, tf (no) p^ebble-cobble gravel, dl5° SSW, pll5°HKW, par applies only to the gravel interbed etc. lasts generally rounded generally subrounded ted. imbricatio n dip and direction ed direction towards whic irding to Appendix 3 D" r-80 r-60 r-40 r-20 Figure 2 MEASURED STRATIGRAPHIC SECTIONS, MARY HILL GRAVEL PIT, PORT COQUITLAM, B.C. TT. and i n o t h e r l i m i t e d e x p o s u r e s on t h e s o u t h f l a n k o f Mary H i l l . B e c a u s e o f l i m i t e d e x p o s u r e , t h e s t r a t i g r a p h i c s u c c e s s i o n o f t h e s e p h a s e s i n u n i t 1 i s no t c e r t a i n , bu t i s t h o u g h t t o be ( y o u n g e s t t o o l d e s t ) : g 1 a c i o l a c u s t r. i ne , g 1 ac i oma r i ne , g l a c i o -f l u v i a l . , t i l l . A r m s t r o n g ( 1965 ) d e s c r i b e d a m a s s i v e s t o n y c l a y e y s i l t u n i t e x p o s e d on t h e s o u t h f l a n k o f t h e h i l l and mapped i t as Semiahmoo D r i f t ( ? ) . F u r t h e r e x c a v a t i o n i n t o t h e h i l l s i n c e t h e n has r e v e a l e d t h a t t h i s b l u e - g r e y s t o n y , c l a y e y s i l t i s o n l y one p h a s e o f t h e g l a c i a l c o m p l e x i n u n i t 1. The w r i t e r f o u n d t h i s p h a s e e x p o s e d i n m e a s u r e d s e c t i o n s M and P. I t i s p r o b a b l y g l a c i o m a r i n e a s i t i s m a s s i v e ( b u t w e a t h e r s t o a b l o c k y s t r u c t u r e ) and p o o r l y c o m p a c t e d , c o n t a i n s few s c a t t e r e d s t o n e s (up t o 2 m d i a . o b s e r v e d ) , has a f i n e r m a t r i x t h a n t h e t i l l p h a s e , and has no p r e f e r r e d p e b b l e o r i e n t a t i o n (shown l a t e r i n F i g . 5 A ) ; h o w e v e r , no s h e l l s o r s h e l l i m p r e s s i o n s we re f o u n d i n i t . The t i l l p h a s e i n c l u d e s ponded g 1 a c i o 1 a c u s t r i n e s t o n y l a m i n a t e d s i l t c o n t a i n i n g t i l l c l a s t s and was o b s e r v e d o n l y i n t h e g u l l i e s a t m e a s u r e d s e c t i o n s B and D. In t h e s e g u l l i e s t h e t i l l i s p a l e g r e e n i s h - b r o w n , v e r y s t o n y and has a s andy t o s i l t y m a t r i x . The g l a c i o l a c u s t r i n e l a m i n a t e d s i l t and f i n e sand p h a s e was e x p o s e d a t m e a s u r e d s e c t i o n P, and on t h e s o u t h f l a n k o f t h e h i l l 70 m w e s t o f m e a s u r e d s e c t i o n M, w h e r e i t o v e r l i e s t h e g l a c i o m a r i n e p h a s e ( F i g . 3 9 ) - The g 1 a c i o 1 a c u s t r i n e p h a s e was p r o b a b l y f o r m e d by s t o n e s d r o p p i n g f r o m d r i f t i n g i c e i n t o 12. mud on t h e b o t t o m o f a g l a c i a l l a k e . S i l t and f i n e s and l a m i n a e a r e commonly b e n t u n d e r o r d r a p e d o v e r s t o n e s i n t h i s p h a s e . Wood f r o m t h i s p h a s e w e r e d a t e d as > 6 2 , 0 0 0 r a d i o c a r b o n y r . B .P . (M. S t u i v e r , U n i v e r s i t y o f W a s h i n g t o n - p e r s . comm.) and as > 4 8 , 0 0 0 and >hh , 0 0 0 r a d i o c a r b o n y r . B .P . (W. A. B l a k e , J r . , p e r s . comm.). L. D. W i l s o n ( G . S . C . Q u a t e r -n a r y P a l e o c o l o g y L a b o r a t o r y , O t t a w a ) r e p o r t e d on t h e l a t t e r s a m p l e as f o l l o w s : " S a m p l e i s h i g h l y d i s t o r t e d , c o m p r e s s e d and l i g n i f i e d . V i s i b l e f e a t u r e s a p p e a r t o be t h o s e f o u n d i n A b i e s s p . ( W e s t e r n F i r ) . C o n d i t i o n o f t h e wood doe s no t p e r m i t p o s i t i v e i d e n t i f i c a t i o n . " G 1 a c i o f 1 u v i a 1 g r a v e l and s and u n d e r l i e t h e m a s s i v e g l a c i o m a r i n e p h a s e a t m e a s u r e d s e c t i o n M and a r e p r o b a b l y o u t w a s h d e p o s i t s . A t m e a s u r e d s e c t i o n B ( shown l a t e r i n d e t a i l i n F i g . k) i n t e r b e d d e d s t o n y s i l t s and w e l l s o r t e d f i n e t o medium sand a r e c o n t o r t e d and f a u l t e d and u n d e r l i e t h e t i l l p h a s e o f u n i t 1. T h e s e s e d i m e n t s may be g1 a c i o 1 a c u s t r i n e and p r o g l a c i a l o u t w a s h d e p o s i t s w h i c h d e v e l o p e d f a u l t s when o v e r r i d d e n by t h e g l a c i e r t h a t d e p o s i t e d t h e o v e r l y i n g t i l l . Due t o l a c k o f e x p o s u r e s , t h e s t r a t i g r a p h i c p o s i t i o n o f t h e s e s e d i m e n t s c a n o n l y be d e s c r i b e d as s u b - t i l l i n u n i t 1. U n i t 2 , s t o n y o r g a n i c c o l l u v i u m , was e x p o s e d o n l y i n t h e g u l l i e s a t m e a s u r e d s e c t i o n s A and B and i n a s m a l l e x p o s u r e a t t h e ba se o f m e a s u r e d s e c t i o n C. As s t a t e d i n t h e l e g e n d , t h i s c o m p l e x has two c r u d e l y i n t e r l a y e r e d p h a s e s : a d e n s e , d e t r i t a l o r g a n i c - r i c h d i a m i c t o n ( e x p o s e d a t s e c t i o n s A ( F i g . 3 2 ) , B, and C) c o n t a i n i n g an a s s o r t m e n t o f o r g a n i c d e b r i s ( l o o k s 13. l i k e t i l l f r o m a d i s t a n c e ) ; and a p o o r l y c o m p a c t e d , s i l t - r i c h d i a m i c t o n ( e x p o s e d o n l y a t s e c t i o n B) c o n t a i n i n g w o o d , and c l a s t s o f g l a c i a l s e d i m e n t s . The w r i t e r s u g g e s t s t h a t b o t h p h a s e s a r e r e w o r k e d o r g a n i c and g l a c i a l d e p o s i t s f o r m e d by mass w a s t i n g p r o c e s s e s on a b u r i e d l a n d s c a p e . Wood f r o m t h e o r g a n i c - r i c h p h a s e a t m e a s u r e d s e c t i o n A d a t e d as 40,200+430 r a d i o c a r b o n y r . B .P . (W. A. B l a k e , J r . , p e r s . comm.) and was i d e n t i f i e d by L. D. W i l s o n ( p e r s . c o m m . ) : " C o n i f e r o u s w o o d , s t r o n g l y c o m p r e s s e d and l i g n i f i e d p r o b a b l y P i c e a s p. ( s p r u c e ) . " From t h e s i l t - r i c h p h a s e a t m e a s u r e d s e c t i o n B, a r o o t d a t e d as 40 ,500 *1700 r a d i o c a r b o n y r . B .P . (W. A . B l a k e , J r . , p e r s . comm.) and was i d e n t i f i e d by R. J . M o t t ( p e r s . c o m m . ) : " C o n i f e r o u s wood somewhat d e c a y e d . F e a t u r e s r e s e m b l e t h o s e o f T suga h e t e r o p h y l l a ( w e s t e r n h e m l o c k ) . " M. S t u i v e r ( U n i v e r s i t y o f W a s h i n g t o n ) a n a l y z e d a n o t h e r wood chunk f r o m t h e o r g a n i c -r i c h pha se a t m e a s u r e d s e c t i o n A and commented on i t as f o l l o w s : " . . . t h e t h i r d s a m p l e a p p e a r s t o have e ven a y o u n g e r age t h a n d e t e r m i n e d p r e v i o u s l y f o r t h i s s t r a t a ( G . S . C . 2 1 3 7 - 4 0 , 2 0 0 - 4 3 0 ) . " J . V. M a t t h e w s ( G . S . C . , O t t a w a ) e x a m i n e d a s a m p l e o f t h e o r g a n i c - r i c h p h a s e and r e p o r t e d : " T h e f o l l o w i n g b e e t l e s we re i d e n t i f i e d i n t h i s s a m p l e : Co 1 e o p t e r a C a r a b i d a e " g r o u n d b e e t l e s " Agonum c o n s i m i l e G y l l e n h a l P r o n o t u m S t a p h y 1 i n i d a e " r o v e b e e t l e s " P r o n o t a , e l y t r a , O l o p h r u m b o r e a l e ( P a y k . ) head s " T h e s p e c i e s i n t h i s s a m p l e a r e n o r t h e r n and c a n n o t be c o l l e c t e d a t V a n c o u v e r t o d a y . A r e l i c t p o p u l a t i o n o f A. c o n s i m i l e a p p a r e n t l y o c c u r s t o d a y a t Duncan on V a n c o u v e r I s l a n d , bu t o t h e r w i s e a l l c o l l e c t i n g r e c o r d s a r e f r o m l o c a l i t i e s i n n o r t h e r n B .C. In o t h e r p a r t s o f 14. Canada i t i s a l s o p r i m a r i l y n o r t h e r n , o c c u r r i n g f r o m Edmonton n o r t h i n A l b e r t a ; C h u r c h i l l and The Pas i n M a n i t o b a ; F o r t S e v e r n , O n t a r i o ; Ungava r e g i o n o f Q u e b e c ; Cape B r e t o n I s l a n d , Nova S c o t i a ; and i n New-f o u n d l a n d and s o u t h e r n L a b r a d o r . A. c o n s i m i l e l i v e s n e a r s t a n d i n g w a t e r w h e r e s u b s t r a t e i s s o a k e d and v e g e t a t i o n i s a b u n d a n t . The d i s t r i b u t i o n o f 0_. b o r e a l e i s l e s s p e r f e c t l y known , bu t i t w o u l d be e n t i r e l y u n e x p e c t e d a t V a n c o u v e r t o d a y . In t h e n o r t h ( N o r t h w e s t T e r r i t o r i e s and A l a s k a ) i t may be c o l l e c t e d i n t h e same b i o t y p e s t h a t . A. c o n s i m i l e o c c u p i e s . H a t c h i n h i s monog raph on t h e b e e t l e s o f t h e P a c i f i c N o r t h -w e s t ( i n c l u d i n g B r i t i s h C o l u m b i a ) doe s no t l i s t 0_. bo r e a 1 e , bu t I s t r o n g l y s u s p e c t t h a t i t doe s o c c u r i n n o r t h e r n m o s t B.C. s i n c e I have c o l l e c t e d i t i n t h e s o u t h e r n p a r t o f t h e Yukon T e r r i t o r y . I t seems q u i t e l i k e l y i n v i e w o f t h e s e f o s s i l s t h a t t h e p e a t f r o m w h i c h t h e y come was d e p o s i t e d d u r i n g a p e r i o d o f c l i m a t e c o l d e r t h a n a t p r e s e n t . " U n i t 3, o r g a n i c b o g ' a n d . s w a m p , d e p o s i t s , o c c u r r e d o n l y a t m e a s u r e d s e c t i o n B w h e r e t h r e e t h i n f i b r o u s and f i s s i l e p e a t l a y e r s ( 1 0 - 4 0 cm t h i c k ) and a l o w e r d i a t o m a c e o u s s a p r o p e l l a y e r ( 5 - 1 0 cm t h i c k ; i d e n t i f i e d by S. F e d e r o v i c h , p e r s . comm.) a r e s e p a r a t e d by o r g a n i c - b e a r i n g s i l t y f i n e sand and m i n o r g r a v e l ( See a l s o F i g . 4 ) . A s a m p l e f r o m t h e s a p r o p e l l a y e r d a t e d as 2 9 , 6 0 0 * 2 0 0 r a d i o c a r b o n y r . B .P . (W. A. B l a k e , J r . , p e r s . comm.) and was d e s c r i b e d by S. F e d e r o v i c h ( p e r s . comm.) as f o l l o w s : "Due t o e x c e s s i v e f r a g m e n t a t i o n , c r i t i c a l i d e n t i -f i c a t i o n was a t t i m e s d i f f i c u l t and u n c e r t a i n , a l l o w i n g o n l y a p a r t i a l l i s t i n g o f t h e d i a t o m t a x a p r e s e n t i n t h e a s s e m b l a g e . I t a l s o p r e c l u d e s a d e t a i l e d e c o l o g i c a l i n t e r p r e t a t i o n . H o w e v e r , t h e d o m i n a n c e o f s p e c i e s c o m -p r i s i n g t h e g e n e r a Eu no t i a and P i nnu1 a r i a s u g g e s t s an o l i g o t r o p h i c , c a l c i u m - p o o r bog e n v i r o n m e n t . " The f r e s h - w a t e r d i a t o m a s s e m b l a g e i n c l u d e s t h e f o l l o w i n g s p e c i e s : " C y c 1 o t e 1 l a c o m t a , C y m b e l l a c i s t u l a , Euno t i a a r c u s , Eunot i a ex i g u a , E u n o t i a a l p i n a ? , Euno t i a 1 una r i s , v a r . S u b a r c u a t a , E u n o t i a p r a e r u p t a , E u n o t i a r o b u s t a , E u n o t i a r o b u s t a v a r . d i adema , M e l o s i r a d i s t a n s , E u n o t i a va1 i da ? , P i nnu1 a r i a i n t e r r u p t a , 15. P i n n u l a r i a ma i o r , P i n n u l a r i a v i r i d i s , v a r . s u d e t i c a ?, P i nnu1 a r i a v i r i d i s , Rhopa 1 od i a g i b b a , T a b e l l a r i a f l o c c u l o s a . 1 1 M. Kuc ( G . S . C . , O t t a w a ) a l s o made t h i s comment on t h e s a p r o p e l s a m p l e : " T h i s i s a most t y p i c a l d i a t o m a c e o u s s a p r o p e l , r a t h e r o 1 i g o t r o p h i c , on w h i c h d e v e l o p e d v a s c u l a r p l a n t ( s e d g y ) g r o w t h . I f t h e r e i s any t i m e i n t e r v a l b e t w e e n t h e s e two c o m p o n e n t s i t i s s h o r t . The s a m p l e i s v e r y u n i f o r m , i s f r e e o f i n t r o d u c e d m a c r o -f o s s i l s , and i s t h u s s u i t a b l e f o r r a d i o c a r b o n d a t i n g . " Wood f r o m t h e l o w e s t p e a t l a y e r d a t e d as 2 8 , 2 0 0 - 2 0 0 r a d i o c a r b o n y r . B .P . (W. A. B l a k e , J r . , p e r s . comm.) and L. D. W i l s o n ( p e r s . comm.) r e p o r t e d : " I d e n t i f i e d as P i c e a s p . ( s p r u c e ) . " D r . J . V . M a t t h e w s e x a m i n e d t h e l o w e s t p e a t l a y e r f o r f o s s i l b e e t l e s and r e p o r t e d as f o l l o w s : " F o s s i 1 s : Co 1 e o p t e r a C a r a b i d a e " g r o u n d b e e t l e s " S c a p h i n o t u s a n g u s t i c o 1 1 i s Mann. E l y t r a S. m a r g i n a t u s F i s c h . E l y t r a P a t r o b u s f o s s i f r o n s E s c h z . P r o n o t u m S c a r a b a e i d a e " s c a r a b b e e t l e s " Genus ? P r o n o t a , e l y t r a Ch r y s ome 1 i dae Dona c i a s p . E l y t r a " A l l t h r e e o f t h e i d e n t i f i e d s p e c i e s c a n be f o u n d i n t h e V a n c o u v e r a r e a t o d a y . The f i r s t two a r e f o r t h e most p a r t deep f o r e s t s p e c i e s ( S c a p h i n o t u s i n d i v i d u a l s a r e s n a i l e a t e r s ) w h i l e t h e t h i r d o c c u r s n e a r p o n d s . " A f o s s i l s tump (30 cm d i a m e t e r ) f r o m t h e s e c o n d p e a t l a y e r ( F i g . 35) d a t e d 2 7 , 4 0 0 - 4 2 0 r a d i o c a r b o n Y r . B .P . (W. A. B l a k e , J r . , p e r s . comm.) and R. J . M o t t ( p e r s . comm.) s t a t e d : "Wood i s somewhat d e c a y e d and t h e r e f o r e h a r d t o s e c t i o n . I d e n t i f i e d as P i c e a s p. ( s p r u c e ) p r o b a b l y P. s i t c h e n s i s . 16. Wood f rom the h i g h e s t pea t l a y e r d a t e d as 27,000-490 r a d i o c a r b o n y r . B.P. (W. A. B l a k e , J r . , p e r s . comm.) and R. J . Mot t ( p e r s . comm.) r e p o r t e d : " I d e n t i f i e d as P i c e a s p. (cf. P. s i t c h e n s i s ) ( s i t k a s p r u c e ) . " U n i t 3 u n c o n f o r m a b 1 y o v e r l i e s u n i t 2, as i s shown l a t e r in F i g s , 4 and 34. U n i t 4, r u s t y sandy g r a v e l , was e x p o s e d in t he m i d d l e o f the p i t a t measu red s e c t i o n s A, C ( F i g . 3 1 ) , F, J , and X. T h i s u n i t c o n t a i n s w o o d - b e a r i n g o r g a n i c s i l t l a y e r s and g r a d e s down-ward i n t o f i n e sand and s i l t a t t he b a s e . At measu red s e c t i o n J c r o s s - b e d d e d and f a u l t e d g r a v e l l y sand c o n t a i n i n g d i s p e r s a l c o a l and wood c l a s t s u n d e r l i e s s t o n y c l a y e y s i l t o f u n i t 5 ( F i g . 30) and has been mapped w i t h u n i t 4; however i t may b e l o n g to t h e sand o f u n i t 6. Wood f rom s e c t i o n A d a t e d 26,200*320 r a d i o c a r b o n y r . B.P. (W. A. B l a k e , J r . , p e r s . comm.) but was not i d e n t i f i e d . From s e c t i o n X a f o s s i l l o g (3 m l o n g , 30 cm d i a . ) d a t e d 26,900 -320 r a d i o c a r b o n y r . B.P. (W. A. B l a k e , J r . , p e r s . comm.) and L. D. W i l s o n ( p e r s . comm.) r e p o r t e d : " I d e n t i f i e d as A b i e s s p . ( w e s t e r n f i r ) . " Wood f rom r u s t y f l u v i a l g r a v e l , 30 cm above the p a l e o s l o p e on u n i t 2 (and 1 m s o u t h o f t he 26,200 d a t e ) a t measured s e c t i o n A, was d a t e d as 26,000-310 r a d i o c a r b o n y r . B.P. (W. A. B l a k e , J r . , p e r s . comm.) and R. J . Mot t ( p e r s . comm.) i d e n t i f i e d i t : " . . . a s P i c e a s p . ( s p r u c e ) . " Wood f rom a t h i n o r g a n i c s i l t l a y e r a t t he top o f u n i t 4 a t measu red s e c t i o n C d a t e d as 25,800-310 r a d i o c a r b o n y r . B.P. (W. A. B l a k e , J r . , p e r s . comm.) ; R. J . Mot t ( p e r s . comm.) i d e n t i f i e d i t : " . . . a s P i c e a s p . ( s p r u c e ) . " 17. U n i t 5, s t o n y c l a y e y s i l t , was o b s e r v e d a t s e c t i o n s A, C, J ( F i g . 29, 30) and L. F o s s i l s h e l l s and s h e l l f r a g m e n t s we re f o u n d i n t h i s u n i t , w h i c h s t r o n g l y s u g g e s t s a g l a c i o m a r i n e o r i g i n . T h i s u n i t i s g e n e r a l l y m a s s i v e bu t v a r i e s i n c o m p a c t n e s s , s t o n i -n e s s , and m a t r i x p r o p o r t i o n s o f s a n d , s i l t , and c l a y ; i t may i n p a r t be t i l l . B o u l d e r s up t o 1 m d i a . we re o b s e r v e d i n t h i s u n i t . Be tween m e a s u r e d s e c t i o n s A and C u n i t 5 p i n c h e s o u t t o t h e w e s t and i s r e p r e s e n t e d o n l y by a b o u l d e r l a y e r a t s e c t i o n C. U n i t 6, s a n d . ( F i g s . 2k, 2 5 ) , i s e x p o s e d i n s e v e r a l s e c t i o n s i n t h e m i d d l e and t o w a r d s t h e b a c k o f t h e p i t . I t i s d e s c r i b e d a d e q u a t e l y i n t h e l e g e n d o f F i g . 3 and i s t h o u g h t t o be p r o g l a c i a l c h a n n e l and f l o o d p l a i n d e p o s i t s , w h i c h g r a d e upward i n t o u n i t 7 g r a v e l and s a n d . Pa 1 e o c h a n n e l s a r e s h a l l o w (0.1 t o 1 m d e e p ) and w i d e (I t o 10 m w i d e ) . I s o l a t e d s t o n e s and s t o n e c l u s t e r s w e r e p r o b a b l y d r o p p e d f r o m f l o a t i n g i c e o r t r e e p a r t s c a r r i e d by t h e m e l t w a t e r s t r e a m s . A r m s t r o n g and C l a g u e ( i n p r e s s ) r e p o r t e d t h e p o l y n o m o r p h a s s e m b l a g e ( i d e n t i f i e d by J . T e r a s m a e ) f r o m p e a t y s i l t i n Quad ra Sand a t Mary H i l l a s f o l l o w s : P i c e a (88% o f a b o r e a l p o l l e n ) , P i n u s (6%), Sa1 i x (6%) A r te rn ? s a , Compos i t a e , and L y c o p o d i um. A t m e a s u r e d s e c t i o n D wood f r o m a t h i n p e a t l a y e r a t t h e v e r y b a s e . o f , u n i t 6 ( F i g . 2 6 - - d i r e c t 1 y o v e r 1 y i n g u n i t 1) d a t e d as 18,600*190 r a d i o c a r b o n y r . B ,P , (W. A. B l a k e , J r . , p e r s . comm.) and L. D. W i l s o n ( p e r s . comm.) r e p o r t e d : " I d e n t i f i e d as P i c e a s p . ( s p r u c e ) . " U n i t 7 o c c u r r e d as s o u t h w a r d - d i p p i n g f o r e s e t g r a v e l and s and beds on t h e f l a n k s o f Mary H i l l ( F i g . 2 2 ) . I t was p r o b -a b l y d e p o s i t e d by v o l u m i n o u s m e l t w a t e r d i s c h a r g e s as p r o g l a c i a l d e l t a s b e t w e e n t i l l s and c l o s e t o a d v a n c i n g i c e m a r g i n s . 1 8 . Pa 1 e o c h a n n e l s a r e d e e p e r and n a r r o w e r t h a n t h o s e i n u n i t 6. U n i t 8 , t i l l ( F i g s . 2 0 , 21) was e x p o s e d a t s e v e r a l s e c t i o n s o v e r t h e e n t i r e a r e a o f t h e p i t and o c c u r s i n a t l e a s t t h r e e s o u t h w a r d - d i p p i n g l a y e r s on t h e s o u t h e r n s l o p e o f Ma ry H i l l ( A r m s t r o n g and H i c o c k , 1 9 7 5 ) ; e a c h l a y e r i s t r u n c a t e d by t h e n e x t y o u n g e s t l a y e r and s e p a r a t e d by o u t w a s h g r a v e l s ( u n i t 7) • T h i s u n i t v a r i e s f r o m c o m p a c t , p l a t y , and s t o n y l o d g e m e n t t i l l s , d e p o s i t e d a t t h e b a s e o f g l a c i e r i c e , t o p o o r l y c o m p a c t e d , m a s s i v e ( o r c o n t o r t e d ) , and l e s s s t o n y f l o w t i l l s w h i c h w e r e p r o b a b l y d e p o s i t e d as mud s l i d e s a t t h e e d g e s o f w a s t i n g i c e m a r g i n s . T i l l c o l o u r v a r i e s f r o m d a r k g r e y t o d u l l r e d d i s h -o r a n g e , d e p e n d i n g on t h e d e g r e e o f o x i d a t i o n . S t o n e s up t o 5 m d i a . we re o b s e r v e d i n i t ( F i g . 2 1 ) . U n i t 9 , g l a c i o m a r i n e s e d i m e n t s ( F i g . 1 9 ) , was s e e n o n l y a t m e a s u r e d s e c t i o n L (and i n c o n t a c t w i t h u n i t 5) a t t h e t i m e o f m a p p i n g bu t was o b s e r v e d e l s e w h e r e i n t h e p i t by p r e v i o u s w o r k e r s ( A r m s t r o n g , 1 9 5 3 , 1 9 6 5 ; L e a r n i n g , 1968 ; Rowe, 1975 ; A r m s t r o n g and H i c o c k , 1 9 7 5 ) . As s t a t e d i n t h e l e g e n d o f F i g . 3 , t h e c h a r a c t e r i s t i c f e a t u r e s o f t h i s u n i t a r e : b l o c k y s t r u c t u r e , manganese s t a i n i n g on j o i n t s u r f a c e s , t h e p r e s e n c e o f m a r i n e s h e l l s and f r a g m e n t s , and s c a t t e r e d s t o n e s . S t o n e s up t o 10 cm d i a . we re o b s e r v e d i n t h i s u n i t a t s e c t i o n L. In 1962 J . E. A r m s t r o n g c o l l e c t e d a f o s s i l s h e l l a s s e m b l a g e f r o m t h i s u n i t on t h e s o u t h f l a n k o f Mary H i l l and t h e f a u n a we re i d e n t i f i e d by F. J . E. Wagner ( p e r s . comm.) as f o l l o w s : P e l e c y p o d a : Nucu1 a  t e n u i s ( M o n t a g u ) , N u c u l a n a f o s s a ( B a i r d ) , Ch1amys h i nd s i i ( C a r p e n t e r ) , C l i n o c a r d i u m b l a n d u m ( G o u l d ) , C l i n o c a r d i u m c i l i a t u m 19. ( F a b r i c i u s ) , S e r r i p e s g r oen1 a n d i c u s ( B r u g i e r e ) , Ma coma c a 1 c a r e a ( G m e l i n ) , Macoma i n c o n s p i c u a ( B r o d e r i p and S o w e r b y ) , Macoma  p l a n i u s c u l a ( G r a n t and G a l e ) , Mya t r u n c a t a ( L i n n e ) , H i a te1 l a  a r c t i ca ( L i n n e ) ; G a s t r o p o d a : T r i c h o t r o p i a c a n c e l l a t a ( H i n d s ) , N a t i c a c l a u s a ( B r o d e r i p and S o w e r b y ) ; A n n e l i d a : Se r pu1 a ve rm i c rema r ked : u1 a r i s ( L i n n e ) ; C i r r i p e d i a : Ba1 anus s p . D r . Wagner a l s o " E x c e p t f o r Macoma p l a n i u s c u l a , w h i c h has n o t p r e v i o u s l y been i d e n t i f i e d f r o m t h i s a r e a , a l l o f t h e s e s p e c i e s a r e common i n t h e Newton s t o n y c l a y . M. p l a n i u s c u l a i s a c o l d - w a t e r f o r m , r a n g i n g a t p r e s e n t f r o m t h e A r c t i c Ocean t o P u g e t S o u n d . " U n i t 10, s u p r a 1 i t t o r a 1 l a g g r a v e l , f o r m s a t h i n ( l e s s t h a n one m e t e r ) c o v e r o v e r u n i t s 8 and 9 and was p r o b a b l y f o r m e d by o c e a n waves and s p r a y p o u n d i n g a g a i n s t and w a s h i n g o v e r t h e s e s e d i m e n t s , when t h e y f o r m e d t h e u p p e r s l o p e s o f a b e a c h a t one t i m e . The b e a c h c o n c e p t f o r t h e f o r m a t i o n o f t h e s e g r a v e l s was f i r s t c o n c e i v e d by Bu rwa sh (1918 ) and J o h n s t o n (1 9 2 3 ) . A c o m p l e t e t r a n s i t i o n may be f o u n d ( F i g . 15) b e t w e e n w e l l w a s h e d , o x i d i z e d , a l m o s t c l e a n p e b b l e - c o b b l e g r a v e l t o a s l i g h t l y r e w o r k e d , s l i g h t l y o x i d i z e d d i a m i c t o n c o n t a i n i n g a s i l t y m a t r i x . G e n e r a l l y u n i t 10 o c c u r s as a d u l l r e d d i s h - o r a n g e s a n d y g r a v e l c o n t a i n i n g a few s h e l l c a s t s , and s t o n e s i n t h e same s i z e r a n g e t h a t o c c u r s i n u n i t s 8 and 9 • F i g . k i s a more d e t a i l e d d i a g r a m m a t i c s e c t i o n ( w i t h no v e r t i c a l e x a g g e r a t i o n ) o f t h e d r a i n a g e t r e n c h a t m e a s u r e d s e c t i o n B, t h e o n l y s i t e w h e r e u n i t s 1, 2 , and 3 o f F i g . 3 o c c u r r e d t o g e t h e r , and r e p r e s e n t s one s i t e w h e r e v a r i o u s p h a s e s o f t h e s e u n i t s c o u l d be d i f f e r e n t i a t e d . He re an u n c o n f o r m i t y ( F i g . 3 4 , 3 5 ) was u n c o v e r e d b e t w e e n two o r g a n i c u n i t s : t h e " F o s s i l Bog and (No Vertical Exaggeration.) L E G E N D If SAND I j Sond with gravel interbeds. FOSSIL BOG and GYTTJA DEPOSITS |,!!llj!;!.j Thin fissile peat and sapropel layers containing fossil tree stumps (up to 30cm dia.), roots, logs, (up to 3m long),and insects. ( J fine sand and silty fine sand containing finely disseminated organic matter and fossil insects; and minor iron stained,well sorted fine gravel. STONY COLLUVIAL ORGANIC COMPLEX J Dense, stony and gritly, detrital organic - rich diamicton (weathered surface resembles till) containing fossil twigs, leaves, wood pieces , and insects; stones up t< i. observed at this site. pxvrq Moderately to poor ly compac led , contorted, stony, silt - rich diamicton containing fossil wood pieces and roots.clasts of laminaled stony silt,and grovel and sc L j i l i d and lenses. "UNDIFFERENTIATED" GLACIAL COMPLEX Laminated stony silts; compact, slightly con tor ted. containing clasts of till; probably ponded. Ittii'irii^ l Till;massive, moderately to well compacted; pale brownish green colour. [ ' , ^ ] Contorted and faulted stony silts interbedded with well sorted fine to medium stony sand; faults probabIy caused by the load of overriding ice. Section not exposed below this line • • • ' Geological contact; observed, inferred 27.400 ± 420 (GSC 2107. SP,WD) X d a t e Radiocarbon date in years B. P. sapropel or wood Lab. no..Geological Survey of Canada INDEX MAP DETAILED DIAGRAMMATIC CROSS-SECTION Figure 4 GULLY AT MEASURED SECTION B r o o 2 1 . G y t t j a D e p o s i t s , " and t h e " C o l l u v i a l O r g a n i c C o m p l e x . " The i m p o r t a n c e o f t h i s s u r f a c e i s u n c e r t a i n as t h e " F o s s i l Bog and G y t t j a D e p o s i t s " may have o l d e r , b u r i e d , o r g a n i c l a y e r s t h a t w o u l d n a r r o w t h e h i a t u s b e t w e e n t h e two u n i t s ; and t h e " C o l l u v i a l O r g a n i c C o m p l e x " may c o n t a i n o r g a n i c m a t e r i a l y o u n g e r t h a n what has been d a t e d f r o m i t so f a r . The ba se o f t h e " S a n d " u n i t i s an u n c o n f o r m i t y and t h e t o p o f t h e " ' U n d i f f e r e n t i a t e d 1 G l a c i a l C o m p l e x " r e p r e s e n t s a b u r i e d l a n d s c a p e . On t h e r i g h t s i d e o f t h e f i g u r e t h e s e two s u r f a c e s m e r g e . The l e g e n d a d e q u a t e l y d e s c r i b e s t h e v a r i o u s p h a s e s o f t h e s e d i m e n t u n i t s , and r a d i o c a r b o n d a t e s , w h e r e o b t a i n e d , a r e p l o t t e d on t h e d i a g r a m . A g e o l o g i c a l map was no t d rawn f o r t h e p i t as e x p o s u r e s o c c u r r e d g o r i l y n e a r - v e r t i c a l f a c e s and g u l l i e s , w h i c h c o n t i n u -o u s l y c h a n g e d as g r a v e l e x c a v a t i o n p r o c e e d e d . Soon t h e p i t w i l l be i n f i l l e d and g r a d e d and a g e o l o g i c a l map w o u l d be m e a n i n g l e s s . Rowe (1975 ) d rew a g e o l o g i c a l map o f t h e p i t as i t a p p e a r e d one day i n t h e s p r i n g o f 1 975 . Q u a t e r n a r y H i s t o r y and C o n c l u s i o n s Mary H i l l has been s u b j e c t e d t o a t l e a s t two g l a c i a t i o n s s e p a r a t e d by a t l e a s t one n o n g l a c i a l i n t e r v a l . D u r i n g t h e l a s t g l a c i a t i o n two s t a d e s ( m i n o r g l a c i a l i n t e r v a l s w i t h i n t h e g l a c i -a t i o n ) o c c u r r e d , p o s s i b l y s e p a r a t e d by an i n t e r s t a d e (a warmer i n t e r v a l b e t w e e n t h e s t a d e s , d u r i n g w h i c h p e a t f o r m e d ) . T h r e e g l a c i o m a r i n e l a y e r s s u g g e s t t h a t o c e a n w a t e r s c o v e r e d t h e h i l l a t l e a s t t h r e e t i m e s d u r i n g t h e P l e i s t o c e n e e p o c h . The h i l l i t s e l f i s n o t a r e c e n t g e o n o r p h o 1 o g i c a I f o r m (and no t b e d r o c k - c o r e d ( A r m s t r o n g , 1 957 ) ) bu t p r o b a b l y e x i s t e d more t h a n 6 2 , 0 0 0 y e a r s ago (Q.L-'\3k), a l t h o u g h i n a d i f f e r e n t s h a p e , d u r i n g g l a c i a l c o n d i t i o n s when u n i t 1 ( F i g . 3 ) , t h e u n d i f f e r e n t i a t e d g l a c i a l c o m p l e x , was b e i n g d e p o s i t e d . The e a r l i e s t p h a s e o f u n i t 1 t o be l a i d down was t h e s u b -t i l l c o n t o r t e d s i l t and f i n e sand i n m e a s u r e d s e c t i o n B ( F i g . h) They a p p e a r t o be g 1 a c i o 1 a c u s t r i n e o r p r o g l a c i a l d e p o s i t s . G l a c i e r i c e a d v a n c e d s o u t h w a r d ( F i g . 5A) o v e r t h e s e .sed i m e n t s and r e s h a p e d t h e m . Lodgement t i l l was l a i d down and t h e s u b -t i l l d e p o s i t s f a i l e d and became c o n t o r t e d u n d e r t h e w e i g h t o f g l a c i e r i c e . M e l t w a t e r f i l l e d h o l l o w s on t h e t i l l s u r f a c e and f l o a t i n g i c e d r o p p e d s t o n e s and t i l l c l a s t s i n t o t h e ponded muds The g l a c i e r t h e n r e t r e a t e d as t h e c l i m a t e warmed and C o a s t M o u n t a i n s - d e r i v e d o u t w a s h g r a v e l and s and ( F i g s . 5 C , D, A p p e n d i x we re d e p o s i t e d , p r o b a b l y i n t o t h e s e a , w h i c h a p p a r e n t l y f o l l o w e d t h e g l a c i e r ' s r e t r e a t and e v e n t u a l l y d r owned Mary H i l l . D u r i n g t h i s t i m e g l a c i o m a r i n e s e d i m e n t s w e r e p r o b a b l y d e p o s i t e d up t o a t l e a s t kO m a b o v e p r e s e n t sea l e v e l . D r i f t i n g i c e r a n d o m l y ( F i g . 5A) d r o p p e d s t o n e s m a i n l y o f n o r t h e r n p r o v e n -a n c e ( F i g s . 5 C , D, A p p e n d i x 2) i n t o s e a - f l o o r muds. The l a n d t h e n i s o s t a t i c a 1 1 y r e b o u n d e d f a s t e r t h a n t h e e u s t a t i c a l l y r i s i n g sea and t h e o c e a n f l o o r became e x p o s e d . M e l t w a t e r f r o m t h e r e t r e a t i n g i c e s h e e t f i l l e d d e p r e s s i o n s i n t h e r a i s e d s ea f l o o r w h i c h may have been f o r m e d by t h e s c o u r i n g a n d / o r p e r c u s s i o n o f d r i f t i n g i c e k e e l s . R h y t h m i c a l l y l a m i n a t e d g 1 a c i o 1 a c u s t r i n e s i l t s c o n t a i n i n g w i d e l y s c a t t e r e d , C o a s t M o u n t -a i n s - d e r i v e d ( F i g s . 5 C , D, A p p e n d i x 2 ) , d r o p s t o n e s w e r e l a i d down i n t h e s e d e p r e s s i o n s i n a s i m i l a r manner d e s c r i b e d f o r t h e g l a c i o m a r i n e p h a s e o f u n i t 1. S c a t t e r e d wood f r a g m e n t s we re 23. A GLACIAL DIAMICTON PEBBLE*FABRICS Inferred d i r ec t i on of i based on strong, weak, and ferred pebble (long axis) t ions (Appendix 3) Stony Clayey S i l t • Glacioi O T i l l (unit 8) x Stony Clayey S i l t (uni' + T i l l phase of Undiffer. Complex (unit 1) A Massive Stony S i l t phase of Undi f fer i G l a c i a l Complex (unit 1) ated G l a c i a l _The r a t i o of long axis length/intermediate axis length for most pebbles measured was 1.5 to 2.0. 95% of a l l pebble long axis measured in th is p i t dipped less than 25°, and 60% dipped less than 10°; 55% dipped Northward {aga: of i ce r. B PALEOCURRENT DATA A Pebble-Cobble Sandy Gravel (unit 7, F i g . 3) O Sand (unit 7) • Sandy Gravel (unit 4) / Measurements done on: Cross-bedding; paleochannel widths 5cm to 5m (large scale) ! Cross-bedding; paleochannel widths up to 5cm (small scale) I Pebble imbricat ion l Foreset bedding Inferred d i r ec t i on of stream flow More than one measurement taken at same s i l (eg. Foreset bedding in un i t 7, and large scale paleochannels in unit 6 were both analysed at same s i te ) ,1 1 f 1 1 1 C PEBBLE*PROVENANCE (see F ig . D for Samples taken from: G ' Supra l i t to ra l Lag Gravel (unit 10, F i g . 3) ® T i l l (unit 8) • Pebble-Cobble Gravel (unit 7) O Sand (unit 6) H Stony Clayey S i l t (unit 5) B Sandy Gravel (unit 4) , 0 F o s s i l Bog and Gyt t ja Deposits (unit 3). 0 C o l l u v i a l Organic Complex (unit 2) LB Undi f ferent iated G l a c i a l Complex (unit 1) * pebbles having Cascade Mtns- source (Eastern provenance) 100 0 0 i % pebbles having Coast Mtns. source 10QJ {Northern provenance) -C Sand (unit 6, F i g . 3) pebble sample i n T which 80% of the pebbles have a Coast I Mtns. source (Northern provenance) and 20% have a Cascade Mtns. source (East-ern provenance) 123° 122° D GENERALIZED REGIONAL GEOLOGY: PEBBLE SOURCE AREAS. (modified a f ter Roddick e t . a l . , 1973: G.S.C. Open F i l e Geolog ica l Map #165) r T r ^ . i GRANITIC AND ASSOCIATED ROCK TYPES ( including low grade metaplutonics, metavol' E-n-j.-nri VOLCANIC ROCK TYPES piij:::iii:i ( including flows, t u f f s , and breccias) J iljf ill QUARTZITE, CHERT, PELITE, AND ARGILLITE OTHER ROCK TYPES {including medium to high grade metamorphics, sedimentary, and ultramafics) UNCONSOLIDATED (QUATERNARY) SEDIMENTS Pebbles ranging from 1 to i d ia . were Fig.5 RESULTS OF SOME FIELD WORK DONE IN MARY HILL GRAVEL PIT: A, GLACIAL DIAMICTON PEBBLE FABRICS; B, PALEOCURRENT DATA; C, PEBBLE PROVENANCE, DJ GENERALIZED REGIONAL GEOLOGY SHOWING SOURCE AREAS FOR PEBBLES IN C. 24. d e p o s i t e d i n t h e g 1 a c i o 1 a c u s t r i n e s i l t s and may r e p r e s e n t t r e e s g r o w i n g a l o n g t h e p r e h i s t o r i c l a k e s h o r e ; h o w e v e r , t h e y a r e w e l l r o u n d e d c l a s t s and we re p r o b a b l y r e w o r k e d f r o m an o l d e r n o n -g l a c i a l s e d i m e n t u n i t . A l a n d s c a p e was d e v e l o p e d on u n i t 1. The g e o l o g i c h i s t o r y o f Ma r y H i l l i m m e d i a t l e y a f t e r t h i s g l a c i a t i o n has n o t been u n r a v e l l e d . A b o u t 4 0 , 0 0 0 y e a r s ago a s t o n y o r g a n i c c o l l u v i u m ( u n i t 2 , F i g . 3) was d e p o s i t e d . I t f o r m e d on a s l o p e a t t h e edge o f a d e p r e s s i o n , p r o b a b l y d u r i n g a n o n g l a c i a l i n t e r v a l , by mass w a s t i n g p r o c e s s e s m i x i n g o r g a n i c d e p o s i t s ( c o n t a i n i n g s p r u c e and w e s t e r n h e m l o c k t r e e s ) and g l a c i a l s e d i m e n t s . P e b b l e s f r o m u n i t 2 have a d o m i n a n t n o r t h -e r n p r o v e n a n c e ( F i g s . 5C , D, A p p e n d i x 2 ) . A l a n d s c a p e was d e v e l o p e d on u n i t 2. A l a r g e t i m e gap seems t o e x i s t b e t w e e n 4 0 , 0 0 0 and 3 0 , 0 0 0 y r . B .P . a t Mary H i l l , u n l e s s t h e " F o s s i l Bog and G y t t j a D e p o s i t s " ( u n i t 3 , F i g . 3) have b u r i e d o r g a n i c l a y e r s o l d e r t h a n 3 0 , 0 0 0 y r . B .P . t h a t w o u l d n a r r o w t h e h i a t u s ; o r t h e " C o l l u v i a l O r g a n i c C o m p l e x " ( u n i t 2) c o n t a i n s o r g a n i c m a t e r i a l y o u n g e r t h a n 4 0 , 0 0 0 y r . B .P . A r m s t r o n g ( i n p r e p . ) has e v i d e n c e e l s e w h e r e i n t h e F r a s e r L o w l a n d s u g g e s t i n g t h a t o r g a n i c d e p o s i t s we re f o r m e d b e t w e e n 3 0 , 0 0 0 and 4 0 , 0 0 0 y r . B .P . P r e s u m a b l y t h e warm n o n -g l a c i a l i n t e r v a l a l s o p e r s i s t e d t h r o u g h t h i s a p p a r e n t t i m e gap a t Mary H i l l . L a y e r e d bog and g y t t j a d e p o s i t s c o n t a i n i n g s p r u c e t r e e s f o r m e d b e t w e e n 3 0 , 0 0 0 and 2 7 , 0 0 0 y e a r s a g o , a g a i n s t a s l o p e d e v e l o p e d on t h e o r g a n i c c o l l u v i u m a t m e a s u r e d s e c t i o n B ( F i g . 4 ) . P e b b l e s f r o m a g r a v e l i n t e r b e d i n u n i t 3 have a d o m i n a n t l y n o r t h e r n p r o v e n a n c e ( F i g s . 5C, D. A p p e n d i x 2 ) . A l a n d s c a p e was f o r m e d on u n i t 3-25. F l u v i a l s i l t , s a n d , and g r a v e l c o n t a i n i n g d e t r i t a l wood c l a s t s ( u n i t k, F i g . 3) we re t h e n d e p o s i t e d a g a i n s t t h e s l o p e on t h e o r g a n i c c o l l u v i u m a b o u t 2 6 , 0 0 0 y e a r s a g o . At l e a s t one w o o d - b e a r i n g o r g a n i c s i l t l a y e r c o n t a i n i n g b u r i e d l o g s up t o k m l o n g and 30 cm d i a . o c c u r s i n u n i t k, i n d i c a t i n g t h e e x i s t e n c e o f a b u r i e d f o r e s t ; i n c 1 u d i n g w e s t e r n f i r . S t r e a m s f l o w e d s o u t h -wa rd ( F i g . 5B) and p e b b l e s w e r e m a i n l y d e r i v e d f r o m t h e C o a s t M o u n t a i n s ( F i g s . 5C, D, A p p e n d i x 2) d u r i n g d e p o s i t i o n o f t h i s u n i t . At m e a s u r e d s e c t i o n J c r o s s - b e d d e d and f a u l t e d s and o c c u r s b e l o w s t o n y c l a y e y s i l t ( u n i t 5) and has been mapped w i t h u n i t k. H o w e v e r , i t i s t e x t u r a l l y s i m i l a r t o s and o f u n i t 6 and may r e p -r e s e n t an e a r l y p h a s e o f p r o g l a c i a l o u t w a s h d u r i n g t h e l a s t g 1 a c i a t i o n , w h i c h was i n t e r r u p t e d by a l o c a l i c e a d v a n c e f r o m t h e e a s t and n o r t h e a s t . A l a n d s c a p e was d e v e l o p e d on u n i t h. F o s s i 1 i f e r o u s s t o n y c l a y e y s i l t ( u n i t 5, F i g . 3) was l a i d down up t o a t l e a s t 75 m a b o v e p r e s e n t sea l e v e l l e s s t h a n 2 6 , 0 0 0 y e a r s ago when t h e o c e a n p r o b a b l y c o v e r e d Mary H i l l as t h e l a n d was i s o s t a t i c a 1 1 y d e p r e s s e d by a p i e d m o n t i c e l o b e and m e l t i n g i c e b e r g s and r a f t s d r o p p e d s t o n e s i n t o s e a - b o t t o m muds. P e b b l e s f r o m t h i s u n i t have a s u b s t a n t i a l e a s t e r n c o m p o n e n t i n t h e i r p r o v e n a n c e ( F i g s . 5C, D, A p p e n d i x 2 ) . P e b b l e f a b r i c s ( F i g . 5A) a r e i n c o n c l u s i v e f o r t h i s u n i t a s two o f t h e t h r e e f a b r i c s a r e s t r o n g l y o r i e n t e d and a s o u t h t o s o u t h w e s t i c e a d v a n c e o v e r t h e g l a c i o m a r i n e d e p o s i t s p r o b a b l y o c c u r r e d , t h e r e b y d i s t u r b i n g t h e g l a c i o m a r i n e s e d i m e n t s and m i x i n g them w i t h t i l l . F a u l t s w e r e p r o b a b l y d e v e l o p e d i n t h e u n d e r l y i n g s and by t h e w e i g h t o f g l a c i e r i c e d u r i n g t h i s t i m e . A l a n d s c a p e was f o r m e d on u n i t 5-26. By a b o u t 1 8 , 600 y e a r s a g o , when t h e c l i m a t e had w a r m e d , t h e i c e m a r g i n had r e t r e a t e d f r o m Mary H i l l and a t h i n wood ( s p r u c e ) - b e a r i n g p e a t l a y e r f o r m e d a t t h e ba se o f t h e s and o f u n i t 6. A f t e r f o r m a t i o n o f t h e p e a t l a y e r f i n e t o medium p r o -g l a c i a l s and was d e p o s i t e d by d i s t a l m e l t w a t e r s t r e a m s o f l ow d i s c h a r g e s f l o w i n g s o u t h w a r d ( F i g 5 B ) , i n w i d e (1 t o 10 m) , s h a l l o w (0.1 t o 1 m deep ) and p r o b a b l y b r a i d e d c h a n n e l s . D u r i n g t h i s t i m e an i c e s h e e t was p r o b a b l y a d v a n c i n g s o u t h w a r d i n t h e C o a s t M o u n t a i n s . E v e n t u a l l y t h e s m a l l s t r e a m s became g r e a t e r m e l t w a t e r d i s c h a r g e s w i t h i n c r e a s i n g c o m p e t e n c e , f l o w i n g i n l a r g e r , d e e p e r c h a n n e l s and c a r r y i n g i n c r e a s i n g amoun t s o f C o a s t M o u n t a i n s - d e r i v e d ( F i g s . 5C, D, A p p e n d i x 2) g r a v e l . I s o -l a t e d s t o n e s and s t o n e c l u s t e r s w e r e p r o b a b l y d r o p p e d f r o m m e l t -i n g i c e b l o c k s a n d / o r t r e e p a r t s c a r r i e d by m e l t w a t e r s t r e a m s . As t h e i c e s h e e t a p p r o a c h e d t h e i m m e d i a t e a r e a o f Mary H i l l l a r g e s o u t h w a r d - f 1 o w i n g m e l t w a t e r d i s c h a r g e s ( F i g . 5B) d e p o s i t e d C o a s t M o u n t a i n s - d e r i v e d ( F i g s . 5C, D, A p p e n d i x 2) g r a v e l and . s and o f u n i t 7, i n t o t h e sea as d e l t a i c f o r e s e t beds d i p p i n g away f r o m t h e h i l l w h i l e t h e l a n d was b e i n g i s o s t a t i c a 1 1 y d e p r e s -s e d . The i c e s h e e t e v e n t u a l l y a d v a n c e d i n t o t h e a r e a and t i l l , u n i t 8, was d e p o s i t e d . P r e s u m a b l y t h e i c e m a r g i n r e t r e a t e d b r i e f l y ; more d e l t a i c o u t w a s h ( u n i t 7) was d e p o s i t e d ; t h e i c e m a r g i n a d v a n c e d a g a i n , d e p o s i t i n g a s e c o n d t i l l w h i c h t r u n c a t e d t h e f i r s t ; and t h i s p r o c e d u r e was r e p e a t e d o n c e more t o f o r m a t h i r d t i l l t r u n c a t i n g t h e p r e v i o u s t w o . Ou twash g r a v e l was d e p o s i t e d b e l o w , b e t w e e n , and a b o v e t h e t i l l s ( F i g . 3). P e b b l e s f r o m u n i t 8 a l s o have a d o m i n a n t n o r t h e r n p r o v e n a n c e as do t h o s e 27. f r o m u n i t 7 ( F i g s . 5C, D, A p p e n d i x 2 ) . Some e a s t e r n - d e r i v e d p e b b l e s we re p r o b a b l y r e w o r k e d f r o m o l d e r s e d i m e n t s i n t h e a r e a . D u r i n g e a c h i c e a d v a n c e t h e g l a c i e r o v e r r o d e and i n c o r p o r a t e d i t s own r o u n d e d o u t w a s h and r e d e p o s i t e d i t i n t h e t i l l s . D u r i n g e a c h d e p o s i t i o n a l e p i s o d e o f u n i t s 6, 7 . and 8 , Ma r y H i l l was r e s h a p e d a g a i n and new l a n d s c a p e s we re f o r m e d , b u r y i n g and t r u n -c a t i n g t h e p r e v i o u s l a n d s c a p e s . In summary , t h e l a s t i c e a d v a n c e a t Ma r y H i l l was p r o b a b l y t h e m a j o r one d u r i n g t h e l a s t g l a c i a t i o n . The l a s t g l a c i a t i o n may have s t a r t e d w i t h a c o o l i n g c l i m a t e a b o u t 2 6 , 0 0 0 y e a r s ago w h i l e t h e u p p e r s and o f u n i t k ( a t m e a s u r e d s e c t i o n J ) was b e i n g d e p o s i t e d by d i s t a l o u t w a s h s t r e a m s i n w i d e , s h a l l o w c h a n n e l s . P e r h a p s a l o c a l i c e l o b e a d v a n c e d f r o m t h e e a s t and n o r t h e a s t d u r i n g t h e d e p o s i t i o n o f u n i t 5, t h e n r e t r e a t e d r a p i d l y w h i l e t h e m a i n , d i s t a n t , i c e s h e e t c o n t i n u e d t o a d v a n c e f r o m t h e n o r t h . W i t h t h e l o c a l i c e s h e e t gone f r o m Mary H i l l and t h e m a i n s h e e t y e t t o come, p e r h a p s i n t e r s t a d i a l c o n d i t i o n s e x i s t e d t h e r e w h i l e a t h i n p e a t l a y e r f o r m e d and d i s t a l , b r a i d e d l o w -c h a r g e m e l t w a t e r s t r e a m s c o n t i n u e d t o d e p o s i t s and o f u n i t 6 i n w i d e , s h a l l o w c h a n n e l s . E v e n t u a l l y t h e ma in i c e s h e e t r e a c h e d Mary H i l l and d e p o s i t e d u n i t s 7 and 8. The i c e l a t e r r e t r e a t e d as t h e c l i m a t e became warmer and t h e sea c o v e r e d t h e h i l l o n c e more b e f o r e t h e l a n d c o u l d i s o -s t a t i c a l l y r e b o u n d f a s t e n o u g h , and f o s s i 1 i f e r o u s " G l a c i o m a r i n e S t o n y C l a y e y S i l t " ( u n i t 9 , F i g . 3) was l a i d down up t o a t l e a s t 76 m a b o v e p r e s e n t sea l e v e l . As t h e l a n d c o n t i n u e d t o r i s e , now f a s t e r t h a n t h e e u s t a t i c a l l y r i s i n g sea l e v e l , t h e s u r f a c e o f Mary H i l l ( u n d e r l a i n m a i n l y by u n i t s 8 and 9) e x p e r i e n c e d t h e p o u n d i n g o f waves and s u r f d u r i n g s t o r m s , w h i c h p a r t i a l l y t o c o m p l e t e l y d i s a g g r e g a t e d u n i t s 8 and 9 and l e f t a t h i n c o v e r o f u n i t 10, " S u p r a 1 i t t o r a 1 Lag G r a v e l . " A r m s t r o n g ( i n p r e s s ) has shown t h a t o t h e r i c e a d v a n c e s ( F o r t L a n g l e y , Sumas) o c c u r r e d t o t h e e a s t o f t h e C o q u i t l a m -P o r t Moody a r e a a f t e r t h e l a s t r e t r e a t o f i c e f r o m Mary H i l l . D u r i n g p o s t - g l a c i a l ( H o l o c e n e ) t i m e s e d i m e n t s have been d e p o s i t e d a r o u n d Mary H i l l by t h e F r a s e r , P i t t , and C o q u i t l a m R i v e r s ; and on t h e h i l l by c r e e k s , mass w a s t i n g , and man. Mary H i l l was r e s h a p e d d u r i n g e a c h g l a c i a l and n o n g l a c i a l i n t e r v a l and f i n a l l y by m a r i n e a c t i o n . Thus t h e h i l l i s a c o m p o s i t e o n e , made up o f many b u r i e d l a n d s c a p e s , e a c h m a s k i n g a n d / o r t r u n c a t i n g t h e ones c o n s t r u c t e d b e f o r e i t . 29 CHAPTER THREE: LOWER COQUITLAM VALLEY I n t r o d u c t i o n C o q u i t l a m v a l l e y , w h i c h commences i n t h e e x t r e m e s o u t h e r n p a r t o f t h e C o a s t M o u n t a i n s o f B r i t i s h C o l u m b i a , eme rge s o n t o t h e F r a s e r L o w l a n d 20 km e a s t o f V a n c o u v e r . I t i s a g l a c i e r -c a r v e d b e d r o c k v a l l e y ( A r m s t r o n g and B r o w n , 1 9 5 4 ) , t h e b o t t o m o f w h i c h i s f i l l e d w i t h Q u a t e r n a r y s e d i m e n t s t h a t a r e d e e p l y i n c i s e d by C o q u i t l a m R i v e r . Q u a t e r n a r y s e d i m e n t s a r e w e l l e x p o s e d a l o n g P i p e l i n e Road i n g r a v e l p i t s i n t h e we s t bank o f t h e l o w e r p a r t o f t h e C o q u i t lam R i v e r v a l l e y b e l o w C o q u i t l a m L a k e and t h e G r e a t e r V a n c o u v e r W a t e r s h e d . In t h e s e p i t s s e v e r a l b u r i e d l a n d s c a p e s have been e x p o s e d . Lower C o q u i t l a m v a l l e y has t h e h i g h e s t c o n c e n t r a t i o n o f g r a v e l p i t s i n t h e F r a s e r L o w l a n d . Deeks Sand and G r a v e l Co. o p e n e d t h e f i r s t p i t b e f o r e 1942 , w h i c h was l o c a t e d i n t h e a r e a b e t w e e n P i p e l i n e Road and p i t s B and C ( F i g . 1 ) . J a c k Cewe L t d s t a r t e d t e s t p i t s 4 km t o t h e n o r t h up t h e v a l l e y i n 1958 . O t h e r s m a l l p i t s i n t h e v a l l e y we re l o c a t e d i n Crown Land and we re f r e e l y e x c a v a t e d by t h e p u b l i c f o r t h e i r p e r s o n a l u se u n t i l t h e D i s t r i c t o f C o q u i t l a m impo sed l a n d - u s e b y - l a w s f o r t h e a r e a i n t h e mid 1 9 6 0 ' s . S i n c e t h e n s e v e r a l c o m p a n i e s have opened and e n l a r g e d g r a v e l p i t s i n t h e w e s t bank o f t h e r i v e r v a l l e y ( F i g . 1 ) . T a b l e I s u m m a r i z e s g r a v e l p i t o w n e r s h i p and o p e r a t i o n s t h a t have o c c u r r e d o v e r t h e y e a r s on t h e w e s t s i d e o f t h e v a l l e y . T A B L E I: G R A V E L P I T O P E R A T I O N S ON T H E WEST BANK OF T H E LOWER C O Q U I T L A M R I V E R V A L L E Y * P i t ( F i g . 1) OWNER O P E R A T O R D A T E S R e m o v a l o f S a n d a n d G r a v e l f rom 1 A p r i l 75 t o 31 M a r c h 76 ( m 3 ) " " T Y P E OF O P E R A T I O N IN 1976 B G r e a t e r V a n c o u v e r S e w e r a g e a n d D r a i n a g e D i s t r i c t a s a b o v e C a n d C T r u c k i n g W e s t - L i n G r a v e l S u p p l i e s ? t o 1975 1975 t o p r e s e n t 2 7 8 , 0 4 2 f r o n t e n d l o a d e r s , dump t r u c k s , s o r t i n g e q u i p m e n t . C J . J . A l l a r d , C . J . S m i t h e r s , R. B. S e l k i r k , D. K e e n a n , A . G . T e r r y A l l a r d C o n t r a c t o r s L t d . 19 6 0 1 s t o p r e s e n t 6 , 0 0 0 a s a b o v e D K i e w i t & S o n s o f C a n a d a L t d . K a s k B r o s . R e a d y M i x L t d . a s a b o v e s a m e s a m e C a n d C T r u c k i n g e a r 1 y 1960's t o ? ? t o e a r l y 1976 e a r l y 1 9 7 6 t o p r e s e n t 27,627 f r o n t e n d l o a d e r s , dump t r u c k s ; p i t r u n o p e r a t i o n w i t h p o r t a b l e s o r t i n g e q u i p m e n t i n r e s e r v e E D a n d R S a n d a n d G r a v e l L t d . A l l a n J o h n s o n s a m e J o h n s o n T r u c k i n g L t d . e a r l y 1 9 6 0 ' s t o ? ? t o p r e s e n t 232 , 166 a s a b o v e F ( n o r t h end) F ( s o u t h e n d ) C . B. S c o t t a n d E . A . G r a v e s J a c k Cewe L t d . K i e w i t £ S o n s o f C a n a d a L t d . C o l u m b i a B i t u l i t h i c L t d . S a n d S S a n d a n d G r a v e l L t d . u n t i l e a r l y 1 9 7 0 ' s n o n e s a m e s a m e f r o m 1 9 6 0 ' s t o ? e a r l y 1960's t o 1 9 7 5 1 9 7 5 t o p r e s e n t ? t o 1 9 6 0 ' s 1 9 6 0 ' s t o p r e s e n t d o r m a n t s i n c e a t l e a s t 1 9 7 2 a s a b o v e G (ma i n p i t ) G ( e x t r e m e n o r t h e n d ) J a c k C e w e L t d . A . M. a n d K. M. F u l a w k a A l l a r d C o n t r a c t o r s L t d . s a m e s a m e s a m e l a t e 1 9 5 0 ' s t o p r e s e n t 1 t o 1 9 7 5 1 9 7 5 t o p r e s e n t 688,463 17,158 f r o n t e n d l o a d e r s , dump t r u c k s , s o r t i n g e q u i p m e n t , a s p h a l t p l a n t . f r o n t e n d l o a d e r s , dump t r u c k s ; p i t r u n o p e r a t i o n I n f o r m a t i o n p r o v i d e d by B u r t T h o m a s , P. E n g . D i s t r i c t o f C o q u i t l a m * * V a l u e o f p i t r u n m a t e r i a l r a n g e s f r o m 8 0 $ t o $ 1 . 0 0 p e r c u b i c y a r d (0 . 7 6 rn ^ ) * S c r e e n e d g r a v e l a n d c r u s h e d r o c k i s s o l d up t o $ 1*. 2 5 p e r c u b i c y a r d . The Deeks Sand and G r a v e l Co. became D e e k s - M c B r i d e L t d . by I 960 ( L e a r n i n g , 1968) and t h e y and G. H. P h i l l i p s C o n t r a c t i n g L t d . o p e r a t e d two p i t s i n t h e a r e a b e t w e e n P i p e l i n e Road and p i t s B and C. In t h e l a t e 1 9 6 0 ' s L a f a r g e C o n c r e t e L t d . became t h e o w n e r - o p e r a t o r s o f t h a t a r e a , and i n 1974 t h e y c l o s e d down t h e p i t and t h e p r o p e r t y was c o n s i g n e d t o t h e C o q u i t l a m P a r k s B r a n c h . D u r i n g f i e l d wo rk v e r y f ew e x p o s u r e s r e m a i n e d i n t h i s a r e a . Learn ing ( 1968 ) r e p o r t e d t h a t d u r i n g t h e e a r l y 1960 1 s t h e o p e r a t i n g p i t s i n t h e v a l l e y u sed d i e s e l s h o v e l s t o l o a d t r u c k s w h i c h c a r r i e d t h e g r a v e l e i t h e r o u t o f t h e p i t o r t o s o r t i n g e q u i p m e n t e l s e w h e r e i n t h e p i t . From most p i t s i n t h e l o w e r C o q u i t l a m R i v e r v a l l e y , g r a v e l , s a n d , and c r u s h e d r o c k was and i s e x c a v a t e d f o r s a l e . The D i s t r i c t o p e r a t e d t h e r e m a i n i n g p i t s f o r p e r s o n a l u s e . Tens o f m i l l i o n s o f c u b i c m e t e r s o f m a t e r i a l have been removed f r o m t h e s e p i t s s i n c e t h e e a r l y 1 9 4 0 ' s . From A p r i l 1, 1 9 7 5 , t o M a r c h 31, 1976 , 1.25 m i l l i o n m^ o f sand and g r a v e l , v a l u e d a t a p p r o x i m a t e l y $1.5 m i l l i o n ( f o r p i t run m a t e r i a l ) , we re e x c a v a t e d f r o m t h e p i t s . S i n c e t h e c l o s u r e o f t h e Mary H i l l g r a v e l p i t i n 1975 one of ( p i t A, F i g . 1 ) , t h e Cewe p i t has becomej^the l a r g e s t i n t h e p r o v i n c e , e x t e n d i n g 1200 m a l o n g P i p e l i n e Road w i t h an a v e r a g e w i d t h o f 300 m, c o n t a i n i n g v e r t i c a l f a c e s s t a n d i n g 100 m h i g h and h a v i n g a v e r t i c a l d r o p o f 150 m f r o m t o p t o b o t t o m . N e a r -v e r t i c a l f a c e s i n p i t F r e a c h 75 m i n h e i g h t . S e d i m e n t e x p o -s u r e s i n t h e p i t s a r e c o n f i n e d t o n e a r - v e r t i c a l f a c e s and t o g u l l i e s as most o f t h e p i t a r e a s a r e u n d e r l a i n by b u l l d o z e d and s l u m p e d m a t e r i a l . 32. M e a s u r e d S e c t i o n s F i g . 6 shows t h e s t r a t i g r a p h i c s e c t i o n s w h i c h we re m e a s -u r e d w i t h a W a l l a c e and T i e r n a n a l t i m e t e r i n t h e g r a v e l p i t s on t h e w e s t s i d e o f t h e C o q u i t l a m R i v e r v a l l e y . T h e s e m e a s -u r e d s e c t i o n s l i e a l o n g one c r o s s s e c t i o n l i n e p a r a l l e l t o t h e v a l l e y a x i s and f o u r s m a l l c r o s s s e c t i o n l i n e s n o r m a l t o i t ( I n d e x map, F i g . 6). A d i a g r a m m a t i c b l o c k d i a g r a m i n c o r p o r a t i n g a l l t h e s e s e c t i o n s i s shown l a t e r i n F i g . 7. F i e l d d a t a a r e p l o t t e d on e a c h s e c t i o n , w h e r e t h e wo r k was d o n e , and a r e c o d e d i n t h e l e g e n d . The d a t a a r e a l s o r e c o r -ded on maps u n d e r " Q u a t e r n a r y H i s t o r y and C o n c l u s i o n s " i n t h i s c h a p t e r o r i n t h e a p p e n d i c e s . D i a g r a m m a t i c C o m p o s i t e S e c t i o n s F i g . 7 i s a d i a g r a m m a t i c b l o c k d i a g r a m o f t h e w e s t bank o f t h e l o w e r C o q u i t l a m R i v e r v a l l e y c o n t a i n i n g t h e m e a s u r e d s e c t i o n s d rawn i n F i g . 6. T h i s d i a g r a m i l l u s t r a t e s t h e b u r i e d l a n d s c a p e s and m u l t i p l e v a l l e y s t h a t w e r e f o r m e d i n t h e s e d i m e n t s d u r i n g Q u a t e r n a r y t i m e . G e o l o g i c a l c o n t a c t s shown by s o l i d l i n e s i n d i -c a t e whe re i n f o r m a t i o n i s known f r o m o t h e r , l e s s w e l l - e x p o s e d s e c t i o n s , and b r o k e n c o n t a c t s i n d i c a t e w h e r e i n f o r m a t i o n was e x t r a p o l a t e d . The s e d i m e n t u n i t s a r e d e s c r i b e d i n t h e l e g e n d ; h o w e v e r , a d d i t i o n a l i n f o r m a t i o n i s g i v e n b e l o w , c ommenc i n g w i t h t h e o l d e s t u n i t . U n i t 1, w h i c h c o n s i s t s o f n e a r - i m p e r v i o u s p e b b l e - c o b b l e g r a v e l ( F i g s , kk, 4 5 ) , i s e x p o s e d i n v e r t i c a l o v e r h a n g i n g f a c e s up t o 20 m h i g h i n p i t s E, F, and G. I t c o n t a i n s a l m o s t e n t i r e l y EZ3 L E G E N D Supralittoral lag gravel T i l l ; in places overlain by thin mantle ( supralittoral lag gravel Stony clayey s i l t (thought to be glac: Undifferentiated glacial d r i f t ; includes logement and flow t i l l , gravel and sand, and laminated stony s i l t 21,600 ± 200 Radiocarbon date ( G S C 2203, WD,SH| 'n years B.P. ^ ^ date from wood or shells ^ Lab. na, Geo log ica l Survey of C a n a d a WL01GV Sample no. : WL AL -KB -J N -SS-B.Cl West-Lin gravel pit Allard gravel pit Kaak Bros, gravel pit Johnson gravel pit S and S gravel pit !tc. Measured GV - Gravel SD - Sand ST - s i l t TL - T i l l GM?- Glaciomarine!?) stony clayey s i l 260 2 160 I horizaontally bedded 3 thinly bedded •> laminated 3 cross-bedded; direction of paleoatream flow : taken from large scale paleochannel (width up to S ro) : taken from small scale paleochannel (width up to 5cm) d dipping beds; dip and direction r rippled bedding g contains gravel interbeds and lenses g-psr - characteristic following the dash applies only to the gravel interbeds, < m massive, homogeneous cl contorted f faulted p'platy IS oantAins f o s s i l shells st contains scattered stones and stone clusters pr pebbles and/or cobbles generally rounded psr pebbles and/or cobbles generally subrounded pi pebbles and/or cobbles imbricated; imbrication dip and direction tf t i l l (pebble) fabric analysis done at s i t e ; inferred direction of ice movement (st) - strong preferred pebble orientation (Appendix 5) (wk) - weak preferred pebble orientation (Appendix 5) Fe sediment stained with iron oxide * Elevations plotted beside each upper measured section apply only to that section. E4 ct; contains at least 3 t i l l layers, tfl68 (wk-done on top layer) 12,000*100 (GSC 2177, SH) > 120 , psr, xb235 (la) El Fe , dl0°SM, Fe psr, tfl80°(st st, xbl30°(ss) psr, Fe C2 INDEX MAP AND MEASURED LOCATION OF SECT IONS C3 KB03TL KB04ST B0-\ 60H 40H 20-i Cl , dlO SH, Fe , psr, tfl80°(st) , at, XM30 o(BB) ,p, psr; contains sand and gravel, and lm. s i l t lenses; tfl98°(st) •pebble-cobble gravel, psr, h (below t i l l ) , d 20 S (above sand); Pi05-15°N JN05TL JN04SD JN03ST JK02GV - T O i m I a pebble-cobble gravel, par, contains t i l l claats \f- Pebble-cobble gravel, psr, contains 111 clasts m pTTTB- g, psr, d5°SW, Fe |^ g. psr, d30°SV, pi 10°SH, Fe G4 ct; contains at least one t i l l layer (at top of section); mainly gravelly xb sand below t i l l layer g-psr, xbl20 (ss); in placea s l l t y , In, psr h, tb, (98), ct; contains at least 2 t i l l layers. tfl78°(st-done on lower layer) tb, r, st; contains load casts, convolute bedding, b a l l and pillow structures, and rotted wood tubea m, par, pebble fabric 200° (st); may In part be t i l l i ^ - g-psr p, psr; tfl75°(at) pebble-cobble gravel, h. , tfl99 (wk) pil5°SW r, g-psr, xb010° Fe pebble-cobble gravel, h, pr, pllO NE, crudely xb h, tb, xb020°(ss), Fe t; contalna at least c t; contalna at least 2 t i l l layers, tf178°(st-done on lower layer) h, tb, r, at; contains load casts, convolute bedding, b a l l and pillow structures, and rotted wood tubes m, psr, pebble fabric 200°(st); may In part be t i l l par, tfl75"(st) v pebble-cobble gravel, h, par Ip, psr, tfl99°(wk) Nh. pr, pll5°SW h, tb, r, g-psr, xb010°(sa), Fe id-bearing organle s l i t layer pebble-cobble grovel, h, pr, pll0° NE, crudely xb •ntalns at least one t i l l layer , pr, pll5°NE; crudely xb . g-psr ct; contalna at 1< - c t , contains at least 3 t i l l layers, tf!68 (wk-done on top layer) -tb, st, psr, xb235°(ls) 500 te 33 : SAMPLE LOCATIONS FOR M E A S U R E D SECTIONS C 5 and F3 F3 tb, xb055 (ss). wood-bearing organic s i l t layer h, pr, crudely xb Fe; lower part of unit i s Gl ct; contains at least one t i l l layer (at top of section); mainly gravelly xb sand below t i l l layer 21,600 + 200 (GSC 2203, WD) g-psr, xbI20 (ss); in places s i l t y , slide deposit; unsorted diam-icton contain-ing logs and debris g-psr, tb, xb055 (ss), Fe; lower part of unit i s s l l t y , lm, r wood-bearing organic s i l t layer h, pr, crudely xb J xb ct; contains at least one t i l l layer h, g-psr, f, xbl60°(ls); In places s i l t y , lm, G3 5|-h, tb, Fe, xb 060° (88); lover part of unit Is s i l t y . In, r ^-wood-bearing organic s i l t ' v J - h, pr, crudely b, tb, g-par, xb, Fe h, par, crudely xb PIT G WAS N O T S A M P L E D METRES 500 1000 hor i zon ta l scale r-260 h240 h220 \-200 hl80 M60 H40 h!20 hlOO h 80 •60 -40 •20 S E A L E V E L Figure 6 MEASURED STRATIGRAPHIC SECTIONS IN THE WEST BANK OF THE LOWER COQUITLAM VALLEY, B. C. L E G E N D SUPRALITTORAL LAG GRAVEL Poorly s o r t e d , commonly contains sandy to s i l t y matr ix conta ins marine s h e l l ca s t s . YELLOW SAND AND GRAVEL Occurs as t op se t , f o r e s e t , and bottomset beds, u .n marine theII c o m ; probably r a i sed marine d e l t a i c and i n t e r t i d a l depos i t s . FOSSILIFEROUS CLAYEY SILT Contains abundant marine s h e l l s ; g lac iomarine d e p o s i t s . e i t h e r marine or Includes p l a t y , compact lodgement ' t i l l ; massive o r con to r ted , compacted f low t i l l ; some laminated stony s i l t (ponded) and openwork g rave l l enses ; boulders up to 3m d i a . observed. PEBBLE-COBBLE GRAVEL AND SAND Foreset bedded i n p l a ce s , moderately to poor ly s o r t e d ; occurs between t i l l l a y e r s ; probably proximal outwash. Wel l s o r ted , g e n e r a l l y subhor i zon ta l l y bedded, cross-bedded ' con ta in ing g r a v e l lenses and i m e r b e d i , and s c a t t e r e d stones and stone c lus ter * ; i n p laces f a u l t e d and con to r ted ; i n p laces laminated, r i p p l e d , conta in ing load cas t s and convolute bedding; probably p r o g l a c i a l outwash. GLACIAL COMPLEX inc ludes a t l e a s t two p l a t y lodgement t i l l s and one g l a c i o -marine ? stony c l ayey s i l t l a ye r separated by outwash sand and g r a v e l . UNDIFFERENTIATED DRIFT Mapped i n exposures which are i nnacces s i b l e• inc ludes lodgement and flow t i l l , sand, g r ave l and laminated stony s i l t . RUSTY SAND AND GRAVEL Well s o r t e d , gene ra l l y h o r i z o n t a l l y t h i n l y bedded, c r o s s -bedded, s t a i ned wi th i r 0 n ox ides ; base o f un i t i s laminated, cross -bedded, and r i p p l e d s i l t y f i ne sands con ta in ing a t h i n wood-bearing o r gan i c s i l t l a y e r ; probably f l u v i a l depos i t s SEMI-IMPERVIOUS COARSE GRAVEL Moderately to w e l l s o r ted , genera l l y subhor i zon ta l l y bedded crude ly cross-bedded cobble g rave l with a coarse sand matr ix probably outwash d e p o s i t s . Present land sur face Area o f measured s e c t i o n Buried landscape (unconformity); observed, i n f e r r e d Geo log i ca l con tac t , observed, i n f e r r e d _ Bedding th icknesses c l a s s i f i e d accord ing to McKee and Weir, 1953. F i g u r e 7 : B L O C K D I A G R A M , W E S T S L O P E of t h e L O W E R C O Q U I T L A M R I V E R V A L L E Y , B . C . 35. g r a n i t i c s t o n e s and few sand l e n s e s . The o r i g i n o f t h i s g r a v e l i s unknown ; t h e m o d e r a t e t o p o o r s o r t i n g s u g g e s t s i t i s g l a c i o -f l u v i a l . U n i t 2 ( F i g s . 4 1 , 4 2 , 43) i s e x p o s e d i n p i t s F and G. I t ' i s composed o f w e l l s o r t e d f l u v i a l s a n d , s i l t , and m i n o r g r a v e l and has a r u s t y c o l o u r . The s t r a t a a r e t h i n l y b e d d e d , c r o s s -bedded (pa 1 e o c h a n n e l s up t o 5 cm deep and 10 cm w i d e ) and r i p -p l e d . Wood f r o m a t h i n o r g a n i c s i l t bed ( n e a r t h e ba se o f t h e u n i t ) i n m e a s u r e d s e c t i o n F3 was d a t e d as > 4 9 , 0 0 0 and > 4 4 , 0 0 0 r a d i o c a r b o n y r . B .P . (W. A. B l a k e , J r . , p e r s . comm.) and was i d e n t i f i e d by L. D. W i l s o n ( p e r s . c o m m . ) : " . . . P i c e a s p . ( s p r u c e ) . " U n i t 3 o c c u r s o n l y i n t h e g u l l y a t m e a s u r e d s e c t i o n F3 ( F i g s . 36, 3 7 , 38) w h e r e i t c o n t a i n s two l o d g e m e n t t i l l s and a m a s s i v e s t o n y c l a y e y s i l t l a y e r s e p a r a t e d by h o r i z o n t a l l y bedded and c r o s s - b e d d e d s andy g r a v e l s . In o t h e r p i t s i t has been c o v e r e d by y o u n g e r s e d i m e n t s and c o n s e q u e n t l y i s n o t e x p o s e d . The m a s s i v e ( w e a t h e r s t o a b l o c k y s t r u c t u r e ) s t o n y c l a y e y s i l t ( F i g . 37) has a f i n e r * m a t r i x t h a n t h e t i l l s ( F i g . 38 ) , c o n t a i n s f e w e r s t o n e s , i s l e s s c o m p a c t , and i s p r o b a b l y g l a c i o m a r i n e ; h o w e v e r , no s h e l l s o r s h e l l i m p r e s s i o n s we re f o u n d i n i t . The g r a v e l s ( F i g . 36) a r e p r o b a b l y g1 a c i o f 1 u v i a 1 . U n i t 4 i s e x p o s e d i n p i t s D, E, F ( F i g s . 2 7 , 2 8 ) , and G and i s m o s t l y s and i n a v a r i e t y o f t e x t u r e s and s t r u c t u r e s . I t i s p r o b a b l y p r o g l a c i a l o u t w a s h d e p o s i t e d by l o w - d i s c h a r g e mean -d e r i n g s t r e a m s f l o w i n g i n s h a l l o w (0.1 t o 1 m d e e p ) , w i d e (1 t o 10 m w i d e ) c h a n n e l s . S c a t t e r e d s t o n e s and s t o n e c l u s t e r s w e r e p r o b a b l y d r o p p e d f r o m i c e o r t r e e p a r t s c a r r i e d i n t h e s t r e a m s . 36. F a u l t s and c o n t o r t i o n s i n t h i s u n i t we re p r o b a b l y c a u s e d by t h e l o a d o f o v e r r i d i n g i c e t h a t d e p o s i t e d u n i t 5- Wood f r o m meas -u r e d s e c t i o n G2, j u s t b e l o w u n i t 5, d a t e d 2 1 , 6 0 0 * 2 0 0 r a d i o c a r b o n y r . B .P . (W. A. B l a k e , J r . , p e r s . comm.) and was i d e n t i f i e d by L. D. W i l s o n ( p e r s . c o m m . ) : " . . .P i c e a s p . ( s p r u c e ) . " U n i t 5, t i l l and a s s o c i a t e d d r i f t , i s e x p o s e d i n a l l p i t s e x c e p t B, w h e r e i t i s b e l i e v e d t o be b u r i e d by y o u n g e r s e d i m e n t s . In most p i t s i t o c c u r r e d i n t h e h i g h e r p a r t s o f n e a r - v e r t i c a 1 , i n a c c e s s i b l e e x p o s u r e s , w h e r e no a t t e m p t was made t o d i f f e r e n -t i a t e t h e many s e d i m e n t l a y e r s w i t h i n i t . In p i t s C and D, how-e v e r , u n i t 5 c o u l d be d i f f e r e n t i a t e d i n t o t i l l ( 5a ) and c o a r s e o u t w a s h g r a v e l and s and ( 5 b ) . T i l l c l a s t s w e r e f o u n d i n t h e o u t w a s h a t p i t C. The t i l l i s h e t e r o g e n e o u s , c o n t a i n i n g w i t h i n i t l e n s e s o f s a n d , g r a v e l , and l a m i n a t e d s t o n y s i l t . I t i s most commonly d a r k g r e y i n c o l o u r bu t p a l e o r a n g e p o r t i o n s a r e a l s o s een w h e r e t h e t i l l has been o x i d i z e d . One t i l l was f o u n d a t p i t D, two t i l l s w i t h i n u n i t 5 o c c u r a t p i t s C and F, and a t l e a s t t h r e e e x i s t a t p i t s E and G. B o t h c o m p a c t l o d g e m e n t and n o n - c o m p a c t e d f l o w ( ? ) t i l l s we re o b s e r v e d i n t h i s u n i t . In many p l a c e s u n i t 5 i s h i g h l y c o n t o r t e d and v a r i o u s s e d i m e n t l a y e r s a r e i n t e r m i x e d , as i n i c e - c o n t a c t d e p o s i t s ( F i g . 2 3 ) . T i l l s a r e t r u n c a t e d by t h e n e x t y o u n g e s t t i l l and r e p r e s e n t l o c a l i c e a d v a n c e s d u r i n g t h e l a s t g l a c i a t i o n ; e a c h e r o d i n g s e d i m e n t s d e p o s i t e d by p r e v i o u s a d v a n c e s . U n i t 5 m a n t l e s t h e C o q u i t l a m v a l l e y f i l l , d i p s s o u t h w a r d a t p i t C, and d i s a p p e a r s b e l o w p i t B u n d e r a t h i c k c o v e r o f y o u n g e r s e d i m e n t s . U n i t 6, c l a y e y s i l t , o c c u r s a t p i t C o n l y and c o n t a i n s a b u n d a n t m a r i n e s h e l l s i n c l u d i n g p e l e c y p o d s , g a s t r o p o d s , 37. a n n e l i d s , and an e c h i n o i d ( F i g . 18 ) . P e l e c y p o d s o c c u r w i t h b o t h v a l v e s and m u s c l e i n t a c t , c o m p l e t e l y s u r r o u n d e d and f i l l e d w i t h d a r k b l u e - g r e y c l a y e y s i l t . A m a t c h i n g p a i r o f Sa x i domu s  G i g a n t e u s v a l v e s ( i d e n t i f i e d by A. H. C l a r k e , p e r s . comm.) d a t e d 12,000*100 r a d i o c a r b o n y r . B .P . (W. A. B l a k e , J r . , p e r s . c o m m . ) . No s t o n e s we re f o u n d a t t h i s s i t e bu t w e r e f o u n d i n s i m i l a r m a t e r i a l e l s e w h e r e ; t h e r e f o r e , t h i s u n i t p r o b a b l y has a g l a c i o -m a r i n e o r i g i n . U n i t 7. s and and g r a v e l , o c c u r s as a c o m p o s i t e m a r i n e d e l t a i n c r e a s i n g i n e l e v a t i o n f r o m p i t s B ( F i g . 17) t o D. The s a n d s and g r a v e l s a r e r u s t y and d i s p l a y t o p s e t , f o r e s e t , and b o t t o m s e t b e d d i n g . S h e l l c a s t s we re f o u n d i n t h e b o t t o m s e t sand beds by A r m s t r o n g ( p e r s . comm.) and t h e y a r e p r o b a b l y i n t e r t i d a l . The d e l t a was p r o b a b l y f o r m e d i n a r i s i n g sea and w<aB' l a t e r t e r -r a c e d by wave a c t i o n as t h e s e a - l e v e l f e l l . U n i t 8 i s a t h i n (up t o 1 m t h i c k ) m a n t l e o f w a v e - w a s h e d s u p r a l i t t o r a l l a g g r a v e l a t t h e t o p o f t h e t e r r a c e s and was f o u n d i n p i t s B, C, and D. I t f o r m e d a s a r e s u l t o f s t o r m waves and s p r a y r e w o r k i n g u n i t 5 on t h e s l o p e s o f t h e l o w e r C o q u i t l a m v a l l e y when t h e t e r r a c e s we re f o r m e d . In p l a c e s a t r a n s i t i o n o c c u r s b e t w e e n g r e y , c o m p a c t t i l l o f u n i t 5 and t h e o v e r l y i n g r u s t y l a g g r a v e l . In most e x p o s u r e s t h e s e d i m e n t u n i t s have u n d u l a t o r y c o n -t a c t s w i t h and t r u n c a t e o l d e r s e d i m e n t s . In many p l a c e s t h e s e c o n t a c t s w e r e o b s e r v e d i n t h r e e d i m e n s i o n s ( F i g . 7 ) . F o r t h e r e a s o n s s t a t e d i n C h a p t e r Two, a g e o l o g i c a l map was no t d rawn f o r t h e l o w e r C o q u i t l a m v a l l e y g r a v e l p i t s . 38. Q u a t e r n a r y H i s t o r y and C o n c l u s i o n s Q u a t e r n a r y s e d i m e n t s w e r e d e p o s i t e d i n t h e l o w e r C o q u i t l a m v a l l e y d u r i n g a t l e a s t two m a j o r a d v a n c e s and r e t r e a t s o f c o n -t i n e n t a l g l a c i e r s and d u r i n g a t l e a s t one n b n g l a c i a l i n t e r v a l . Two g l a c i o m a r i n e l a y e r s i n d i c a t e t h a t t h e C o q u i t l a m v a l l e y became a f i o r d a t l e a s t t w i c e d u r i n g t h e P l e i s t o c e n e e p o c h . M u l t i p l e v a l l e y s r o u g h l y p a r a l l e l t o t h e p r e s e n t C o q u i t l a m R i v e r v a l l e y w e r e d e v e l o p e d i n t h e s e s e d i m e n t s ( F i g . 7 ) - D u r i n g t h e f o r m a t i o n o f e a c h v a l l e y o l d e r s e d i m e n t s we re e r o d e d and removed by i c e a n d / o r w a t e r a c t i o n , t h e n f i l l e d i n by more sed i m e n t s . U n i t 1 i s t h e o l d e s t s e d i m e n t f o u n d i n t h e l o w e r C o q u i t -lam v a l l e y , p r o b a b l y g 1 a c i o f 1 u v i a 1 i n o r i g i n , and was d e p o s i t e d more t h a n 49,000 y e a r s ago ( p r o b a b l y m o r e ' t h a n 62j000 y e a r s a g o , a c c o r d i n g t o QL-194 a t Mary H i l l ) . U n i t 1 was d e p o s i t e d by s t r e a m s f l o w i n g s o u t h w a r d ( F i g s . 8 B , C, D, A p p e n d i x 2) down t h e v a l l e y f r o m t h e C o a s t M o u n t a i n s , p r e s u m a b l y when t h e c l i m a t e was c o o l e r t h a n t h a t o f t o d a y . The s t r e a m s d e p o s i t i n g u n i t 1 heeded d i s c h a r g e s g r e a t enough t o t r a n s p o r t c o b b l e - s i z e d m a t e -r i a l , t h a t o c c u r s i n a s e d i m e n t w h i c h i s m o d e r a t e l y t o p o o r l y s o r t e d , and o u t w a s h s t r e a m s a r e l i k e l y c a n d i d a t e s . T h i s was f o l l o w e d by a p e r i o d o f e r o s i o n d e v e l o p i n g a l a n d s c a p e w h i c h r e p r e s e n t s a r a d i c a l c h a n g e i n s e d i m e n t r e g i m e . The c l i m a t e warmed and n o r t h e a s t w a r d - f 1 o w i n g s t r e a m s ( F i g . 8B) l a i d down u n i t 2 more t h a n 49,000 y e a r s ago ( p r o b a b l y more t h a n 62,000 y e a r s ago ) d u r i n g a n o n g l a c i a l i n t e r v a l . T h e s e we re l o w - d i s c h a r g e s t r e a m s c o m p a r e d t o t h o s e d e p o s i t i n g u n i t 1. An o r g a n i c - r i c h s i l t l a y e r c o n t a i n i n g s p r u c e t w i g s , p o s s i b l y 3 9 . V A GLACIAL DIAMICTON PEBBLE * FABRICS Inferred d i r e c t i o n o f i ce movement, baaed of Strong preferred pebble (long axis) o r ienta t ion (Appendix 3) Weak preferred pebble (long axis) o r ienta t ion (Appendix 3) T i l l (unit 5b, P i g . 7) • T i l l phase of G l a i c a l Complex (unit 3] Massive stony clayey s i l t phase of G l a c i a l Complex (unit 3| The r a t i o of long axis length/intermediate axis length for most pebbles was 1.5 to 2.0, 90* of a l l pebble long axis dipped less than ' 25° , and 57% dipped less than 10°; 15* dipped Northward (against d i r ec t i on of i ce movement) B V A L E O C U R R E N T D A T A • Yellow Sand and Gravel (unit 7. F i g . 7} A Pebble-Cobble Gravel and Sand (unit 5a) O Sand (unit 4) T Rusty Sand and Gravel (unit 2) • Semi-Impervious Coarse Gravel (unit 1) Measurements done on: 1 Cross-bedding; paleochannel widths 5cm to 5m (large scale) 2 Cross-bedding; paleochannel width up to 5cm (small scale) 3 Pebble imbricat ion * Foreset bedding / Inferred d i r ec t i on of stream flow *AA M n m than one measurement taken from same s i t e , (e.g. Foreset bedding and pebble imbricat ion i n un i t 5a were both analysed a t same s i te ) C PEBBLE*PROVENANCE (see F i g . D for Samples taken from: © S u p r a l i t t o r a l Lag Gravel (unit 8, F i g . 7) a Yellow Sand and Gravel (unit 7) 5 T i l l (unit 5b) • Pebble-Cobble Gravel (unit 5a) O Sand (unit 4) • G l a c i a l Complex (unit 3) A Rusty Sand and Gravel (unit 2) V Semi-Impervious Gravel (unit 1) * Pebble sample having Cascade Mtns. source (Eastern provenance) * pebbles having Coast Mtns. source (northern provenance) e.g.-a Pebble sample from un i t 5a in which 90* of the [pebbles have a Coast Mtn3. source (Northern I provenance) and 10* have a Cascade Mtns. source (Eastern provenance) D GENERALIZED REGIONAL GEOLOGY: PEBBLE SOURCE AREAS. (modified a f te r Roddick e t . a l . , 1973: G.S.C. Open F i l e Geological Map #165) r'^L'MI GRANITIC AND ASSOCIATED ROCK TYPES Yi. IVy.l ( including low grade me tamp l u tonics and metavolcanics) VOLCANIC ROCK TYPES ( including flows, t u f f s , and breccias) QUARTZITE, CHERT, PELITE, AND ARGILLITE OTHER ROCK TYPES ( including medium to high grade metamorphics, sedimentary, and ultramaf ics *Pebbles ranging from 1 ' d i a . were m UNCONSOLIDATED (QUATERNARY) SEDIMENTS RESULTS OF SOKE FIELD WORK DONE IN THE LOWER COQUITLAM RIVER VALLEY GRAVEL PITS: A, GLACIAL DIAMICTON PEBBLE FABRICS I B, PALEOCURRENT DATA; C, PEBBLE PROVENANCE( D, GENERALIZED REGIONAL GEOLOGY SHOWING SOURCE AREAS FOR PEBBLES IN C. 40. w i t h some t r e e s g r o w i n g i n i t , f o r m e d a t t h i s t i m e . S c a t t e r e d p e b b l e s i n u n i t 2 have a d o m i n a n t l y n o r t h e r n p r o v e n a n c e ( F i g s . 8C , D, A p p e n d i x 2) and may have been r e w o r k e d f r o m o l d e r s e d i -ment s by s t r e a m s f l o w i n g n o r t h e a s t w a r d i n t o t h e v a l l e y . An e r o s i o n a l p e r i o d f o l l o w e d t h i s and a l a n d s c a p e was d e v e l o p e d on t h e s e depo s i t s . As t h e r e s u l t o f a c o o l i n g c l i m a t e and t h e o n s e t o f a n o t h e r g l a c i a t i o n , s o u t h w a r d - f 1 o w i n g m e l t w a t e r s t r e a m s m o d i f i e d t h e l a n d s c a p e and c o v e r e d i t w i t h s andy g r a v e l o u t w a s h o f u n i t 3-The f i r s t t i l l o f u n i t 3 was d e p o s i t e d on t h e o u t w a s h when i c e a d v a n c e d s o u t h , f r o m t h e C o a s t M o u n t a i n s t o t h e n o r t h ( F i g s . 8A, C, D, A p p e n d i x 2), and f i l l e d t h e C o q u i t l a m v a l l e y . F o l l o w i n g a b r i e f r e t r e a t o f t h e i c e , more o u t w a s h o f u n i t 3 was l a i d down; t h e n t h e i c e r e a d v a n c e d , d e p o s i t i n g t h e s e c o n d t i l l o f u n i t 3-W i t h r enewed c l i m a t i c w a r m i n g t h e i c e r e t r e a t e d a g a i n , more o u t -wash was l a i d down, and t h e sea a p p e a r s t o have i n v a d e d t h e v a l l e y , w h i c h became a f i o r d . The f i o r d l a t e r d i s a p p e a r e d w i t h l a n d u p l i f t . D u r i n g t h i s d e g l a c i a t i o n a s t o n y c l a y e y s i l t l a y e r i n t e r p r e t e d t o be g l a c i o m a r i n e s e d i m e n t s was f o r m e d t o a t l e a s t 135 m a . s . l . when f l o a t i n g i c e p r o b a b l y d r o p p e d s t o n e s i n t o mud on t h e sea f l o o r . F i g . 8C i n d i c a t e s t h a t a l m o s t a l l o f t h e s t o n e a r e d e r i v e d f r o m t h e C o a s t M o u n t a i n s and s u g g e s t s t h a t i c e b e r g s d r i f t e d s o u t h w a r d down t h e f i o r d . F i g . 8A s u g g e s t s t h e s e p e b b l e s a r e s t r o n g l y o r i e n t e d , p e r h a p s i m b r i c a t e d , and t h e i r l o n g a x e s d i p g e n e r a l l y n o r t h w a r d . T h i s g l a c i o m a r i n e ? l a y e r may i n p a r t be t i l l ; h o w e v e r , t h e p e b b l e o r i e n t a t i o n may be c o i n c i d e n t a l . The l a y e r c o n t a i n s f e w e r s t o n e s t h a n t h e t i l l s , 41. t h e m a t r i x i s f i n e r t h a n t h e t i l l s o f u n i t 3 , and t h i s l a y e r i s m a s s i v e and l i t t l e c o m p a c t e d ; w h e r e a s t h e t i l l s a r e p l a t y and h i g h l y c o m p a c t e d . S i m i l a r s e d i m e n t s i n t h e same s t r a t i g r a p h i c p o s i t i o n o c c u r e l s e w h e r e i n t h e F r a s e r L o w l a n d and c o n t a i n m a r i n e s h e l l s ( A r m s t r o n g , i n p r e s s ) . T h e r e f o r e , a g l a c i o m a r i n e o r i g i n f o r t h i s l a y e r i s p r e f e r r e d . A b s o l u t e s e a - l e v e l c h a n g e s due t o i s o s t a t i c and e u s t a t i c e v e n t s d u r i n g d e p o s i t i o n o f t h e s e s e d i m e n t s i s unknown ; o n l y t h e n e t c h a n g e r e l a t i v e t o p r e s e n t sea l e v e l was d e t e r m i n e d . L a c k o f r a d i o c a r b o n d a t e s p r e v e n t s c o n t r o l on t h e t i m i n g o f t h e s e e v e n t s . C l a s t s o f p e a t we re f o u n d i n t h e o u t w a s h g r a v e l s o f u n i t 3 and may have been r e -w o r k e d f r o m u n i t 2. L a n d s c a p e s we re d e v e l o p e d on e a c h o f t h e d e p o s i t s i n u n i t 3 • A f t e r f u r t h e r i s o s t a t i c u p l i f t ( a s s u m i n g t h e s t o n y c l a y e y s i l t l a y e r i s g l a c i o m a r i n e ) s o u t h w a r d - f 1 o w i n g s t r e a m s f r o m t h e C o a s t M o u n t a i n s ( F i g s . 8B , C, D, A p p e n d i x 2) c u t i n t o t h e s e d i -ment s d e p o s i t e d e a r l i e r , and u n i t k was d e p o s i t e d by a b o u t 2 1 , 6 0 0 y e a r s ago on a new l a n d s c a p e , f i l l i n g i n t h e v a l l e y f o r m e d . I f t h e s t o n y c l a y e y s i l t i s n o t g l a c i o m a r i n e , i t i s p r o b a b l y t i l l o r ponded s e d i m e n t s and t h e sea w o u l d no t have e n t e r e d t h e v a l -l e y a t t h a t t i m e , bu t i n s t e a d a n o t h e r i c e a d v a n c e may have o c c u r -r e d . C l i m a t i c c o o l i n g had begun a g a i n by t h e t i m e o f u n i t k d e p o s i t i o n and t h e l o w - d i s c h a r g e s t r e a m s t h a t c a r r i e d t h e s and s i n s h a l l o w ( o . l t o 1 m d e e p ) , w i d e (1 t o 10 m w i d e ) c h a n n e l s d e b o u c h e d f r o m s o u t h w a r d - a d v a n c i n g i c e o f t h e e n s u i n g g l a c i a t i o n , p r o b a b l y s t i l l f a r t o t h e n o r t h i n t h e C o a s t M o u n t a i n s . S c a t -t e r e d s t o n e s and s t o n e c l u s t e r s f o u n d i n t h i s u n i t w e r e p r o b a b l y d r o p p e d f r o m m e l t i n g i c e b l o c k s and t r e e p a r t s c a r r i e d by t h e 42. p r o g l a c i a l s t r e a m s . The d a t e d s p r u c e s t i c k f r o m u n i t k (GSC-2203 2 1 , 6 0 0 * 2 0 0 r a d i o c a r b o n y r . B . P . ) had r o u n d e d end s and a smooth s u r f a c e and may have been r e w o r k e d f r o m a w o o d - b e a r i n g s e d i m e n t l a y e r r e p r e s e n t i n g a n o n g l a c i a l i n t e r v a l and n o t e x -po sed i n t h e l o w e r C o q u i t l a m R i v e r v a l l e y . I t may be t h a t a n o n g l a c i a l i n t e r v a l o c c u r r e d b e t w e e n t h e p e r i o d s when u n i t s 3 and k w e r e d e p o s i t e d , and i s now r e p r e s e n t e d o n l y by a b u r i e d l a n d s c a p e . P e r h a p s two n o n g l a c i a l i n t e r v a l s a r e r e c o r d e d i n t h e P l e i s t o c e n e s e d i m e n t s i n t h e l o w e r C o q u i t l a m v a l l e y , a l t h o u g h o n l y t h e d e p o s i t s o f one ( u n i t 2) a r e e x p o s e d . The a d v a n c i n g g l a c i e r e v e n t u a l l y moved s o u t h w a r d f r o m t h e C o a s t M o u n t a i n s ( F i g s . 8A, C, D, A p p e n d i x 2) and e n t e r e d t h e v a l l e y w h i l e s o u t h w a r d - f l o w i n g m e l t w a t e r s t r e a m s ( F i g s . 8 B , C, D, A p p e n d i x 2) c u t i n t o u n i t 4 and o l d e r s e d i m e n t s and f o r m e d a new v a l l e y , f i l l i n g i t w i t h u n i t 5 a . T h e s e s t r e a m s had g r e a t e r d i s c h a r g e s and f l o w e d i n c h a n n e l s d e e p e r and n a r r o w e r t h a n t h e s t r e a m s d e p o s i t i n g u n i t 4 . As t h e i c e f i l l e d t h e C o q u i t l a m v a l l e y , i t r e m o d e l l e d p r e v i o u s l a n d s c a p e s and d e p o s i t e d t i l l o f u n i t 5b . The s e d i m e n t s o v e r r i d d e n by t h i s i c e ( u n i t s 5 a , k) were f a u l t e d and c o n t o r t e d i n some p l a c e s . A t l e a s t t h r e e t i l l s ( u n i t 5 b ) , s e p a r a t e d by o u t w a s h s and and g r a v e l ( u n i t 5 a ) , and c o n t a i n i n g l e n s e s o f ponded l a m i n a t e d s t o n y s i l t and f i n e s a n d , we re d e p o s i t e d i n t h e v a l l e y by l o c a l g l a c i e r a d v a n c e s and r e t r e a t s d u r i n g t h i s g l a c i a t i o n . Mo s t a r e c o m p a c t p l a t y l o d g e -ment t i l l s f o r m e d a t t h e b a s e o f t h e g l a c i e r i c e ; h o w e v e r , some n o n - c o m p a c t e d , c o n t o r t e d f l o w t i l l s we re d e p o s i t e d as v i s c o u s s t o n y m u d f l o w s a t t h e edge o f w a s t i n g i c e . D u r i n g t h e d e p o s i t i o n o f e a c h t i l l arid o u t w a s h l a y e r , i c e and w a t e r a c t i o n r e s h a p e d t h e o l d e r l a n d s c a p e s and f o r m e d a new o n e . By 1 3 , 0 00 y e a r s B .P . ( b a s e d on r a d i o c a r b o n d a t a o u t s i d e t h e t h e s i s a r e a f r o m J . E. A r m s t r o n g ) , a n o t h e r d e g l a c i a t i o n was i n p r o g r e s s . The c l i m a t e had warmed and as t h e i c e r e t r e a t e d , t h e s e a e n t e r e d t h e C o q u i t l a m v a l l e y , w h i c h became a f i o r d a g a i and m a r i n e and g l a c i o m a r i n e s e d i m e n t s o f u n i t 6 w e r e d e p o s i t e d on a l a n d s c a p e t o a t l e a s t 70 m a . s . l . A b s o l u t e s e a - l e v e l c h a n g e s due t o i s o s t a t i c and e u s t a t i c e v e n t s d u r i n g t h i s t i m e a r e unknown ; o n l y t h e n e t c h a n g e r e l a t i v e t o p r e s e n t sea l e v e l was d e t e r m i n e d . F o l l o w i n g t h i s , u n i t 7 was f o r m e d as a c o m p o s i t e m a r i n e d e l t a by r e c e s s i o n a l o u t w a s h b e i n g c a r r i e d down t h e v a l l e y t o t h e sea by s o u t h w a r d - f 1 o w i n g m e l t w a t e r s t r e a m s ( F i g s . 8B , C, D, A p p e n d i x 2) d e b o u c h i n g f r o m t h e r e t r e a t i n g i c e t o t h e n o r t h . As t h e l a n d i s o s t a t i c a 1 1 y r o s e a b o v e t h e s e a , s u r f p o u n -ded a g a i n s t t h e v a l l e y w a l l s . Waves and s p r a y r e w o r k e d t h e d r i f t o f u n i t 5, f o r m i n g a s u p r a l i t t o r a l l a g g r a v e l , u n i t 8, up t o 175 m a . s . l . w h i l e c a r v i n g t e r r a c e s up t o 140 m a . s . l . i n t o t h e d e l t a o f u n i t 7- T h i s m a r i n e a c t i o n m o d i f i e d o l d e r l a n d s c a p e s and f o r m e d y e t a new o n e , s i m i l a r t o t h e p r e s e n t -day 1 a n d s c a p e . L a t e r i c e a d v a n c e s ( F o r t L a n g l e y , Sumas) o c c u r r e d t o t h e e a s t o f t h e C o q u i t l a m v a l l e y , a f t e r t h e l a s t i c e a d v a n c e i n t o t h e v a l l e y , b u t d i d n o t r e a c h i t ( A r m s t r o n g , i n p r e s s ) . D u r i n g t h e p o s t - g l a c i a l ( R e c e n t ) t i m e s e d i m e n t s have been d e p o s i t e d and e r o d e d by t h e p r e s e n t C o q u i t l a m R i v e r i n t h e b o t -tom o f i t s v a l l e y , and by mass w a s t a g e p r o c e s s e s and human a c t i v i t y on t h e r i v e r b a n k s . 43a. 44. T h r o u g h o u t t h e h i s t o r y o f s e d i m e n t d e p o s i t i o n i n t h e C o q u i t l a m v a l l e y , t e c t o n i c a d j u s t m e n t s p r o b a b l y o c c u r r e d ; how-e v e r , t h e i r i m p o r t a n c e and m a g n i t u d e a r e c o m p l e t e l y u n k n o w n . The l o w e r C o q u i t l a m v a l l e y i s t h e b e s t i l l u s t r a t e d e x a m p l e o f t h e c o m p l e x g e o l o g i c a l makeup o f Q u a t e r n a r y s e d i m e n t f i l l s f o u n d i n g l a c i a t e d b e d r o c k v a l l e y s b o r d e r i n g t h e F r a s e r L o w l a n d . F i g . 7 d e m o n s t r a t e s t h e s p o r a d i c o c c u r r e n c e o f s e d i m e n t u n i t s and b u r i e d l a n d s c a p e s i n t h e w e s t e r n s l o p e o f t h e l o w e r C o q u i t -lam R i v e r v a l l e y . A h y p o t h e t i c a l mode l f o r t h e d i s t r i b u t i o n o f t h e s e u n i t s i n t h e s e d i m e n t f i l l o c c u p y i n g t h e b o t t o m o f t h e l o w e r C o q u i t l a m ( b e d r o c k ) v a l l e y i s shown i n F i g . 9- T h i s s k e t c h i l l u s t r a t e s t h e m u l t i p l e v a l l e y d e v e l o p m e n t t h a t o c c u r r e d i n t h e s e d i m e n t f i l l t h r o u g h o u t Q u a t e r n a r y t i m e . O t h e r s e d i m e n t -f i l l e d , g l a c i a t e d b e d r o c k v a l l e y s b o r d e r i n g t h e F r a s e r L o w l a n d may a l s o c o n t a i n s i m i l a r phenomena . B e c a u s e o f t h e m u l t i p l e v a l l e y f i l l s m a k i n g up t h e Q u a t e r -n a r y s e d i m e n t s i n t h e l o w e r C o q u i t l a m v a l l e y , c o r r e l a t i o n s o f s e d i m e n t u n i t s made on o t h e r t h a n a t h r e e - d i m e n s i o n a l s t u d y s u p p o r t e d by r a d i o c a r b o n d a t e s a r e a t b e s t t e n t a t i v e and may l e a d t o m i s l e a d i n g c o n c l u s i o n s . N i n e s e d i m e n t u n i t s have been mapped i n F i g . 7 and t h e s e can be f u r t h e r s u b d i v i d e d on a s m a l l e r s c a l e . In some p l a c e s a d r i l l h o l e c o u l d p e n e t r a t e more t h a n t w e l v e d i f f e r e n t s e d i m e n t l a y e r s , and i n o t h e r s , o n l y a few m e t e r s away , as few as t w o . 45. CHAPTER FOUR: PORT MOODY DISPOSAL S ITE I n t r o d u c t i o n The b e s t P l e i s t o c e n e e x p o s u r e i n t h e a r e a o t h e r t h a n Mary H i l l and t h e C o q u i t l a m v a l l e y e x p o s u r e s o c c u r s a t t h e P o r t Moody s a n i t a r y l a n d f i l l s i t e on t h e B a r n e t H i ghway ( F i g . l ) . H e r e a s e c t i o n c o n t a i n i n g b u r i e d l a n d s c a p e s i s e x p o s e d , and t h e s e c -t i o n r e p r e s e n t s o n l y a s m a l l p a r t o f a l a r g e r c o m p o s i t e h i l l . The s e c t i o n o b s e r v e d o c c u r s i n a g u l l i e d v e r t i c a l f a c e 35 m h i g h on t h e e a s t s i d e o f a l a r g e c r e e k g u l l y s o u t h o f t h e B a r n e t H i ghway. The p i t was o r i g i n a l l y opened on t h e w e s t s i d e o f t h e g u l l y i n 1963 by S c o t t B r o s . G r a v e l Co. L t d . f o r s and s a l e s . In t h e mid 1 9 6 0 1 s B r i t i s h - A m e r i c a n O i l Co. g a i n e d c o n t r o l o f t h e p i t w h i l e t h e C i t y o f P o r t Moody opened a n o t h e r p i t on t h e e a s t s i d e o f t h e r a v i n e . G a r b a g e and sand we re u sed t o f i l l t h e g u l l y and a d r a i n a g e c u l v e r t was i n s t a l l e d i n p l a c e o f a f o r m e r b r i d g e t o p e r m i t t h e c r e e k t o e n t e r B u r r a r d I n l e t . The p r e s e n t r o a d was t h e n b u i l t o v e r t h e f i l l . The c i t y a l s o u s ed t h e i r p i t on t h e e a s t s i d e o f t h e r a v i n e f o r g a r b a g e d i s p o s a l b u t e x c a v a t e d o n l y m i n o r amoun t s o f sand f o r t h e i r own u se o u t s i d e t h e p i t . In t h e l a t e 1 9 6 0 1 s t h e c i t y became t h e s o l e owne r o f b o t h p i t s and s i n c e t h e n have f i l l e d a l m o s t t h e e n t i r e g u l l y w i t h g a r b a g e and s a n d . D u r i n g f i e l d wo rk a f r o n t end l o a d e r f i l l e d dump t r u c k s w i t h sand and t h e t r u c k s dumped t h e s and on t h e g a r b a g e p i l e s . A b u l l d o z e r t h e n l e v e l l e d t h e g a r b a g e and s p r e a d a b l a n k e t o f s and o v e r i t . O n l y m i n o r amoun t s o f s and w e r e b e i n g e x c a v a t e d and t r u c k e d o u t o f t h e p i t when t h e w r i t e r 4 6 . e x a m i n e d i t . The c i t y i s n o t d i g g i n g f u r t h e r i n t o t h e h i l l -s i d e as t h e v e r t i c a l e a s t f a c e i s t o o h i g h and must be b e n c h e d b e f o r e f u r t h e r e x c a v a t i o n c an p r o c e e d . M e a s u r e d S e c t i o n s The b e s t e x p o s e d s t r a t i g r a p h i c s e c t i o n s i n t h e p i t we re m e a s u r e d w i t h a W a l l a c e and T i e r n a n a l t i m e t e r and a r e shown i n F i g . 10. They l i e a l o n g one s h o r t c r o s s s e c t i o n l i n e p a r a l l e l t o t h e p i t f a c e on t h e e a s t e r n s i d e o f t h e g u l l y m e n t i o n e d i n t h e I n t r o d u c t i o n . The d i a g r a m m a t i c c r o s s s e c t i o n i s shown l a t e r i n F i g . 11. F i e l d d a t a a r e p l o t t e d on e a c h s e c t i o n w h e r e wo rk was done and c o d e d i n t h e l e g e n d . The d a t a a r e a l s o r e c o r d e d on s e p a r a t e maps u n d e r " Q u a t e r n a r y H i s t o r y and C o n c l u s i o n s " i n t h i s c h a p t e r o r i n t h e a p p e n d i c e s . D i a g r a m m a t i c C o m p o s i t e S e c t i o n F i g . 11 i s a d i a g r a m m a t i c c r o s s s e c t i o n t h r o u g h Q u a t e r n a r y s e d i m e n t s e x p o s e d a t t h e P o r t Moody s a n i t a r y l a n d f i l l s i t e . The m e a s u r e d s e c t i o n s i n F i g . 6 and t h e b a s e o f e x p o s u r e a t t h e t i m e o f m a p p i n g a r e p l o t t e d on t h e c r o s s s e c t i o n . G e o l o g i c a l c o n t a c t s shown by s o l i d l i n e s i n d i c a t e w h e r e i n f o r m a t i o n i s known f r o m o t h e r , l e s s - w e l l e x p o s e d s e c t i o n s , and b r o k e n c o n -t a c t s i n d i c a t e w h e r e i n f o r m a t i o n was e x t r a p o l a t e d . S e d i m e n t u n i t s a r e s u f f i c i e n t l y d e s c r i b e d i n t h e l e g e n d . A g e o l o g i c a l map o f t h e p i t was no t d rawn f o r t h e r e a s o n s s t a t e d i n C h a p t e r s Two and T h r e e . Q u a t e r n a r y H i s t o r y and C o n c l u s i o n s The P o r t Moody s i t e has been s u b j e c t e d t o a t l e a s t two 47. 100-1 5 0 ^ B p.psr.tf 214°(wk) g.st, psr ; h,in places tb,r,f, and ct, xb-210°(ls) P.psr g,st, psr; h, in places tb, t, and ct; xb-215°(ls) tb'SncJr hxG-20l°(ls)-SEA Im, silty P.psr.tf 1 3 9 < £ ) - ^ thin (2cm) stony organic silt layer g.st, psr; h, xb-210°( l s metres LEVEL MOO J g.psr-l 50 to UJ Oi Im —' 100 A S E C T I O N D E S C R I P T I O N S 100. 50-PM02TL PM01SD-not sampled SEA LEVEL MOO 50 B S E D I M E N T S A M P L E L O C A T I O N S 122°53' 122°52' 122°5l' wm Tii1 Sand 49°18' Cv Stony S i l t Wood-bearing organic s i l t layer Covered 49°17'I PM01SD Sample Number SD Sand ST S i l t T I T i l l PM Port Moody s i t e A, B,C Measured s t r a t i g r a p h i c sections INDEX MAP AND L O C A T I O N OF MEASURED SECTIONS h tb Im xb ct f P st psr tf h o r i z o n t a l l y bedded t h i n l y bedded laminated cross - bedded; d i r e c t i o n of paleostream flow ( I s ) - measurement taken from large scale paleochannel (width 1 to 5 m) ri p p l e d bedding contains gravel interbeds and lenses contorted fa u l t e d p l a t y contains scattered stones and stone c l u s t e r s pebbles generally subrounded t i l l (pebble) f a b r i c analysis done at s i t e ; i n f e r r e d d i r e c t i o n of i c e movement (st) - strong preferred pebble o r i e n t a t i o n (Appendix 3) (wk) - weak preferred pebble o r i e n t a t i o n (Appendix 3) p- MEASURED STRATIGRAPHIC SECTIONS AT THE PORT MOODY DISPOSAL SITE (PIT H, F i g . 1 ) : 9 ' A. SECTION DESCRIPTIONS, B. SEDIMENT SAMPLE LOCATIONS. 48. 122°53 • 5 j ~ 3 49°18' TILL Platy lodgement t i l l . UPPER SAND Contains scattered stones and stone clusters; grades downward from horizontally bedded, cross-bedded med. sand to thinly bedded and rippled fine sand; probably proglacial outwash and f l u v i a l deposits. FOSSIL SWAMP DEPOSIT Laminated fine sandy s i l t containing f o s s i l leaves, twigs, and logs up to 1 m long and 15 cm dia.; swamp and f l u v i a l deposits. 49°17' INDEX MAP DRIFT LAYER Includes logement t i l l , contorted stony s i l t , and gravelly sand; stony s i l t probably glaciolacustrine; sand probably g l a c i o f l u v i a l . LOWER SAND Identical in texture to unit 5; faulted, subhorizontally bedded, cross-bedded, in places thinly bedded and rippled; contains minor gravel lenses and interbeds, and scattered stones and stone clusters; probably glaciofluvial deposits. Buried land scape (unconformity) and geological contact; observed, inferred. Base of exposure. Area of measured section. F i q 11 DIAGRAMMATIC COMPOSITE SECTION, PORT MOODY DISPOSAL SITE, PO?T MOODY, BRITISH COLUMBIA. 49. g l a c i a t i o n s s e p a r a t e d by a t l e a s t one n o n g l a c i a l i n t e r v a l . D u r i n g t h e s e e v e n t s s e d i m e n t s w e r e d e p o s i t e d on l a n d s c a p e s o f h i l l s w h i c h we re l a t e r r e s h a p e d by w a t e r and i c e a c t i o n . T h e s e s e d i m e n t s and l a n d s c a p e s e v e n t u a l l y made up a c o m p o s i t e h i l l , a r emnan t o f w h i c h e x i s t s a t P o r t Moody t o d a y . The o l d e s t u n i t e x p o s e d i s t h e sand o f u n i t 1. I t was p r o b a b l y d e p o s i t e d as p r o g l a c i a l c h a n n e l and f l o o d p l a i n d e p o s -i t s , d u r i n g a c l i m a t e c o o l e r t h a n t h a t o f t o d a y , by s o u t h w a r d -f l o w i n g s t r e a m s d e b o u c h i n g f r o m a g l a c i e r t o t h e n o r t h i n t h e C o a s t M o u n t a i n s ( F i g s . 12B, C, D, A p p e n d i x 2 ) . S c a t t e r e d s t o n e s and s t o n e c l u s t e r s p r o b a b l y d r o p p e d f r o m m e l t i n g i c e b l o c k s and t r e e p a r t s c a r r i e d i n t h e s t r e a m s . The l o w - d i s c h a r g e s t r e a m s f l o w e d i n s h a l l o w (0.1 t o 1 m d e e p ) and w i d e (1 m t o 10 m w i d e ) c h a n n e l s . F a u l t s i n t h e sand we re p r o b a b l y c a u s e d a f t e r d e p o -s i t i o n by t h e l o a d o f o v e r r i d i n g i c e t h a t d e p o s i t e d u n i t 2 . A l a n d s c a p e was f o r m e d on t h i s u n i t by w a t e r and i c e a c t i o n . The i c e a d v a n c e d f u r t h e r s o u t h w a r d ( F i g . 12A) i n t o t h e P o r t Moody a r e a and l o d g e m e n t t i l l was l a i d down on t h e l a n d -s c a p e w i t h o u t w a s h s and and g r a v e l and ponded s t o n y s i l t o f un i t 2 . As t h e r e s u l t o f a w a r m i n g c l i m a t e , t h e i c e r e t r e a t e d and a n o n g l a c i a l i n t e r v a l b e g a n . L a m i n a t e d s i l t and f i n e sand o f u n i t 3 w e r e d e p o s i t e d i n a swamp, c o n t a i n i n g t r e e s , a g a i n s t t h e s l o p e f o r m e d on t o p o f u n i t 2 . The c l i m a t e c o o l e d a g a i n a f t e r t h a t and p r o g l a c i a l s a nd s o f u n i t h we re d e p o s i t e d by s o u t h w a r d - f 1 o w i n g s t r e a m s f r o m i c e t o t h e n o r t h i n t h e C o a s t M o u n t a i n s ( F i g s . 12B, C, D, A p p e n d i x 2 ) . The s and s g r a d e f r o m t h i n l y bedded and s t o n e l e s s a t t h e b a s e o f 50. GRANITIC AND ASSOCIATED ROCK TYPES ( i n t ' l u d i n q low grado m o t a p l u t o n i c s [ m e t a v o l c a n i ) Samples taken ® T i l l ( u n i t 5, O Upper Hand (ur ID D r i f L l jyc?r (L A Lower .Sand (ur Viq. 11) On * f a b l e s h a v i m , Coa^t MLria. source (>KI rtliE-rn O pebLlt ; aampl 85* o f Clio [Jt'tiblo E l VOLCANIC ROCK TYPES ( l n c l u t l i r i i j f l o w s , t u f f s , and t TZITE, C.flKRT, PELITE, AND ARGILLITE R ROCK TYI'LS r i d d i n g medium Lo h i q h qrad 11 men t i i ry , and u l trama f Li-s) NSOLJ DA'I'ED (OUATERNAKY) SEDIMENTS RESULTS OF SOME FIELD WORK DONE AT THE PORT M00DV DISPOSAL SITE: A, GLACIAL DIAMICTON PEBBLE FABRICS; B, PALEOCURRENT DATA; C, PEBBLE PROVENANCE; D, GENERALIZED RFGIONAL GEOLOGY SHOWING SOURCE AREAS FOR PEBBLES IN C. 51. t h e u n i t i n t o g r a v e l l y c r o s s - b e d d e d s and s i n deep (10 t o 20 cm deep ) and n a r r o w (30 t o 50 cm w i d e ) c h a n n e l s a t t h e t o p , i n d i -c a t i n g t h a t t h e s t r e a m s i n c r e a s e d i n d i s c h a r g e and c o m p e t e n c e as t h e a d v a n c i n g i c e a p p r o a c h e d t h e P o r t Moody a r e a . A l a n d -s c a p e was d e v e l o p e d on u n i t h by w a t e r and i c e a c t i o n . As t h e g l a c i e r a d v a n c e d s o u t h w a r d ( F i g . 1 2 A ) , c o v e r i n g t h e s i t e , i t r e m o l d e d t h e l a n d s c a p e and d e p o s i t e d t i l l o f u n i t 5 w h i c h t r u n c a t e d t h e o l d e r u n i t s . M a r i n e and g l a c i o m a r i n e d e p o s i t s w e r e f o r m e d i n a d j a c e n t a r e a s d u r i n g t h e l a s t i c e r e t r e a t ( C h a p t e r s Two and T h r e e ) ; h o w e v e r , t h e s e d e p o s i t s we re no t f o u n d a t t h e P o r t Moody s i t e . L a c k o f r a d i o c a r b o n d a t e s f r o m t h i s p i t p r e v e n t s c o n t r o l on t h e t i m i n g o f Q u a t e r n a r y e v e n t s ; h oweve r d a t e s f r o m a d j a c e n t a r e a s can p r o b a b l y be e x t r a p o l a t e d f o r some o f t h e u n i t s . The wood l a y e r i s e x p e c t e d t o be 2 5 , 0 0 0 - 6 0 , 0 0 0 y e a r s o l d , b a s e d on d a t e s f r o m s i m i l a r s e d i m e n t s a t Mary H i l l and e l s e w h e r e i n t h e F r a s e r Low l a n d . D u r i n g p o s t - g l a c i a l ( H o l o c e n e ) t i m e s e d i m e n t s have been d e p o s i t e d and e r o d e d by l o c a l s t r e a m a c t i o n , mass w a s t a g e p r o c e s s e s , and human a c t i v i t y . The P o r t Moody s e c t i o n c o n t a i n s f o u r b u r i e d l a n d s c a p e s w i t h i n i t . T h e s e l a n d s c a p e s o c c u r a t t h e b a s e o f e a c h s e d i m e n t u n i t and e a c h u n i t i s , i n most c a s e s , t r u n c a t e d by y o u n g e r o n e s . In t h e s m a l l a r e a t h a t F i g . 11 r e p r e s e n t s u n i t 1 i s t r u n c a t e d by u n i t 2 ; w h i c h was d e p o s i t e d on a s o u t h w a r d - s 1 o p i n g l a n d s c a p e ; u n i t 3 a b u t s a g a i n s t u n i t 2 ; u n i t k o v e r l i e s u n i t 3, and a l s o a b u t s a g a i n s t u n i t 2 ; and f i n a l l y , u n i t 5 t r u n c a t e s u n i t s U, 2 , and 1. I f t h e s e b u r i e d l a n d s c a p e s a r e e x t r a p o l a t e d t o t h e n o r t h 52. rev ['.IrSkigy T i l l (unit 5, Fig. 11) Upper Sand (unit 4) Fo s s i l Swamp Deposit (unit 3) D r i f t Layer (unit 2) Lower Sand (unit 1) present land surface —+—+ former top of T i l l •* - H - -H- former and present case of T i l l - I I I I I former and present top of Upper Sand — •—•— former and present base of Upper Sand former and present top of D r i f t Layer former and present base of D r i f t Layer F i gure 13 HYPOTHETICAL RECONSTRUCTION OF PARTS OF HILLS DEVELOPED DURING QUART-ERNARY TIME NEAR PORT MOODY, BRITISH COLUMBIA. and s o u t h o f t h e p i t , a s e r i e s o f h i l l s f o r m e d a t v a r i o u s s t a g e s t h r o u g h o u t Q u a t e r n a r y t i m e wou l d be r e c o n s t r u c t e d and t h i s i s i l l u s t r a t e d by t h e h y p o t h e t i c a l d i a g r a m i n F i g . 13- In t h i s s k e t c h e a c h s e d i m e n t u n i t has a s l o p i n g c o n t a c t w i t h a d j a c e n t u n i t s and i n most c a s e s i s t r u n c a t e d by y o u n g e r u n i t s . The P o r t Moody s a n i t a r y l a n d f i l l s i t e i s o n l y a s m a l l p a r t o f a l a r g e r c o m p o s i t e h i l l , n o t u n l i k e Mary H i l l d e s c r i b e d i n C h a p t e r Two, and i s a n o t h e r e x a m p l e o f t h e Q u a t e r n a r y c o m -p o s i t e h i l l s , c o n t a i n i n g many b u r i e d l a n d s c a p e s , t h a t o c c u r i n t h e F r a s e r L o w l a n d . 54. CHAPTER F I V E : QUATERNARY STRATIGRAPHY A. C o r r e l a t i o n o f S e d i m e n t U n i t s F i g . 14 i s a h y p o t h e t i c a l f e n c e d i a g r a m t h r o u g h t h e C o q u i t -l a m - P o r t Moody a r e a s h o w i n g t h e Q u a t e r n a r y s t r a t i g r a p h y and c o r r e l a t i o n o f s e d i m e n t u n i t s d e s c r i b e d i n C h a p t e r s Two t o F o u r . The c o r r e l a t i o n i s b a s ed on t h e c o m p o s i t e s e c t i o n s d r awn i n t h e s e c h a p t e r s , s u p p l e m e n t e d by d r i l l h o l e i n f o r m a t i o n . N i n e f o r m a t i o n a l 1 i t h o s t r a t i g r a p h i c u n i t s a r e d i s t i n g u i s h a b l e i n t h e Q u a t e r n a r y d e p o s i t s e x p o s e d i n t h e a r e a . Each u n i t r e p r e s e n t s a g e o1 o g i c - c 1 i m a t i c u n i t t h a t has a g l a c i a l , s t a d i a l , n o n g l a c i a l ( i n t e r g 1 a c i a 1) , o r i n t e r s t a d i a l r a n k . F o r m a l names have been a s s i g n e d t o t h e n i n e 1 i t h o s t r a t i g r a p h i c u n i t s i n F i g . 14, w h i c h have been c o r r e l a t e d w i t h t h e Q u a t e r n a r y s t r a t i g r a p h i c s u c c e s -s i o n e s t a b l i s h e d f o r t h e F r a s e r L o w l a n d ( i n w h i c h t h e C o q u i t l a m -P o r t Moody a r e a i s l o c a t e d ) d u r i n g 1974 t o 1976 by J . E. A r m -s t r o n g and S. R. H i c o c k . C o r r e l a t i o n s o f s e d i m e n t u n i t s ( d e s -c r i b e d i n C h a p t e r s Two t o F o u r ) w i t h t h i s e s t a b l i s h e d s u c c e s s i o n a r e l i s t e d i n T a b l e I I . A b r i e f h i s t o r y o f t h e d e r i v a t i o n o f t h e s u c c e s s i o n f o l l o w s . A r m s t r o n g (1975a) e s t a b l i s h e d t h a t f i v e m a j o r P l e i s t o c e n e f o r -m a t i o n a l u n i t s , e a c h p r o b a b l y r e p r e s e n t i n g a m a j o r g e o l o g i c -c l i m a t i c u n i t , a r e e x p o s e d i n t h e F r a s e r L o w l a n d . T h e s e u n i t s a r e as f o l l o w s ( y o u n g e s t t o o l d e s t ) : F r a s e r G l a c i a t i o n : F r a s e r D r i f t ; O l y m p i a N o n g l a c i a l I n t e r v a l : Quad ra S e d i m e n t s ; M a j o r G l a c i a t i o n : Semiahmoo D r i f t ; N o n g l a c i a l I n t e r v a l : H i g h -b u r y S e d i m e n t s ; M a j o r G l a c i a t i o n ? : W e s t l y n n D r i f t . T A B L E I I C O R R E L A T I O N OF L I T H 0 S T R A T 1 G R A P N I C U N I T S G E O L O G I C - C L I M A T I C UN ITS ( A f L e r A r m s t r o n g , i n a n d A r m s t r o n g a n d H i c o c RAD IOCARBON AGES YEARS B . P . p r e s s k, 1 9 7 6 ) E STABL1 SHED S T R A T I G R A P H I C S U C C E S S I O N FOR THE FRASER LOWLAND ( m o d . a f t e r A r m s t r o n g , i n p r e s s ) SED IMENT U N I T S AT MARY H I L L ( F i g . 3) SED 1 M E NT U N I T S AT COQU ITLAM V A L L E Y ( F i g . 7) S ED IMENT U N I T S AT PORT MOODY ( F i g . 11) HOLOCENE 1 1 , OOO t o p r e s e n t H o l o c e n e S e d i m e n t s F r a s e r R i v e r S e d i m e n t s - - - -P L E I S T O C E N E L A T E W I SCONS IN FRASER G L A C I A T I O N 2 6 , 0 0 0 t o l l , 0 0 0 C a p i l a n o S e d i m e n t s ^ Washon D r i f t Q u a d r a S and C o q u i t l a m D r i f t S u p r a l i t t o r a l L a g G r a v e l ( 1 0 ) * G l a c i o m a r i n e S t o n y C l a y e y S i l t ( 9 ) T i l l ( 8 ) P e b b l e - C o b b l e G r a » e l ( 7 ) S a n d (6 ) S t o n y C l a y e y S i l t ( 5 ) S u p r a l i t t o r a l L a g G r a v e l ( 9 ) Y e l l o w S a n d a n d G r a v e l ( 8 ) F o s s i 1 i f e r o u s C l a y e y S i l t ( 7 ) T i l l ( 6 ) P e b b 1 e - C o b b 1e G r a v e l 6 S and ( 5 ) S a n d (4 ) T i l l ( 5 ) ? U p p e r S a n d ( 4 ) M IDDLE WISCONS 1 N O lYMP1 A N O N G L A C I A L 1NTERVAL 6 0 , 0 0 0 ? t o 2 6 , 0 0 0 C o w i c h a n Head F o r m a t i o n * ^ S a n d y G r a v e l ( 4 ) F o s s i l Bog and G y t t j a D e p o s i t s ( 3 ) ? S t o n y C o l l u v i a l O r g a n i c C o m p l e x (2 ) - - - -? F o s s i I Swamp D e p o s i t ( 3 ) M IDDLE OR EARLY W I SCONS IN MAJOR GLAC 1 AT 1 ON p r o b a b l y > 6 2 , 0 0 0 S e m i a h m o o D r i f t U n d i f f e r e n t i a t e d G l a c i a l C o m p l e x (1 ) G l a c i a l C o m p l e x ( 3) ? D r i f t L a y e r ( 2 ) ? L o w e r S a n d ( 1 ) EARLY WISCONS i N ? MAJOR NONGLAC1AL 1 NTERVAL p r o b a b l y > 6 2 , 0 0 0 H i g h b u r y S e d i m e n t s R u s t y S a n d a n d G r a v e l ( 2 ) EARLY OR PRE-W1 SCONS 1N MAJOR G L A C I A T I O N ^ 6 2 , 0 0 0 W e s t l y n n D r i f t j - - - - ? S e r a i - I m p e r v i o u s C o b b l e (1 ) G r a v e ! - - - -k e t s r e f e r t o s e d i m e n t u n i t n u m b e r s i n e a c h f i g u r e . ? Q u e s t i o n m a r k s i n d i c a t e t h a t s e d i m e n t u n i t s b e h i n d t h e i p l a c e d i n t h e e s t a b l i s h e d s t r a t i g r a p h i c s u c c e s s i o n . 56. LEGEND HOLOCENE (11,000 yr. B P . - PRESENT) P&WW) HOLOCENE SEDIMENTS: Kffifta modem stream s i l t , sand and gravel, bog deposits, and slopewash. PLEISTOCENE FRASER GLACIATION (LATE WISCONSIN, 26,000-11,000) CAPILANO SEDIMENTS: raised marine and glaciomarine sand, gravel, and clayey s i l t . VASHON DRIFT: lodgement and flow t i l l , outwash gravel and sand, and substi :ified d r i f t , i medium sand. •el, and interbedded s i l t COQUITLAM DRIFT: glaciomarine? stony clayey s i l t diamicton; may OLYMPIA NONGLACIAL INTERVAL (MIDDLE WISCONSIN, 60,000? _26,000) COWICHAN HEAD FORMATION: bog, swamp, and colluvial organic sediments interbedded with f l u v i a l gravel, sand, and s i l t . MAJOR GLACIATION (MIDDLE OR EAR' Y WISCONSIN, probably >62.000) ' iVJ SEMIAHMOO? DRIFT: •"•."j lodgement t i l l , outwash gravel and sand, glaciomarine? stony clayey s i l t , and glac MAJOR NONGLACIAL INTERVAL (EARLY WISCONSIN ?. probably > 62,000) olacustrine laminated stony s i l t . • MA I IHIH'I Biata E3 HIGHBURY? SEDIMENTS: fl u v i a l sand, organic-bearing s i l t , and gravel. MAJ.OR GLACLAJJON (EARLY OR PRE,-_WISCpNSIN, >62,000) j Tl WESTLYNN DRIFT? ittJ outwash? coarse gravel and minor sand. GRANITIC BEDROCK Geological contact and buried landscape (major unconformity). Water surface. figur. U HYPOTHETICAL QUATERNARY PENCE DIAGRAM : COQUITLAM-PORT MOODY. BRITISH COLUMBIA A r m s t r o n g and H i c o c k (1975) d e s c r i b e d f i v e m a j o r l i t h o -s t r a t i g r a p h i c u n i t s e x p o s e d a t Mary H i l l and a s s i g n e d them t o f o u r o f t h e m a j o r g e o l o g i c - c l i m a t i c u n i t s ( y o u n g e s t t o o l d e s t ) : F r a s e r G l a c i a t i o n : C a p i l a n o S e d i m e n t s , V a s h o n D r i f t ; O l y m p i a I n t e r g 1 a c i a t i o n : Quad ra S e d i m e n t s ; M a j o r G l a c i a t i o n : S e m i a h -moo D r i f t ; N o n g l a c i a l I n t e r v a l : H i g h b u r y S e d i m e n t s . A r m s t r o n g and H i c o c k (1976) l a t e r e s t a b l i s h e d s i x m a j o r 1 i t h o s t r a t i g r a p h i c u n i t s i n t h e l o w e r C o q u i t l a m v a l l e y and c o r r e l a t e d them w i t h f o u r o f t h e m a j o r g e o 1 o g i c - c 1 i m a t i c u n i t s ( y o u n g e s t t o o l d e s t ) : F r a s e r G l a c i a t i o n : C a p i l a n o S e d i m e n t s , V a s h o n D r i f t , Quad ra S a n d ; M a j o r G l a c i a t i o n : Semiahmoo? D r i f t ; N o n g l a c i a l I n t e r v a l : H i g h b u r y ? S e d i m e n t s ; G l a c i a t i o n ? : P r e -H i g h b u r y ? G r a v e l . A d d i t i o n a l i n f o r m a t i o n showed t h a t some o f t h e a b o v e c o r r e l a t i o n s n e e d e d m o d i f i c a t i o n . The t e r m " Q u a d r a " was a p p l i e d t o d e p o s i t s known t o be i n t e r - t i l l f l u v i a l , g l a c i o f l u v i a l , m a r i n e and g l a c i o m a r i n e s e d i m e n t s e x p o s e d i n c o a s t a l s o u t h w e s t e r n B r i t i s h C o l u m b i a and n o r t h w e s t e r n W a s h i n g t o n and t h e d e p o s i t s w e r e a s s i g n e d t o a n o n g l a c i a l i n t e r v a l by A r m s t r o n g and Brown (1953) and F y l e s (1 963). A r m s t r o n g e t a l . (1965) and E a s t e r b r o o k (1969) l a t e r a s s i g n e d Q u a d r a d e p o s i t s t o t h e O l y m p i a n o n g l a c i a l i n t e r v a l . R e c e n t l y C l a g u e (1976) d e m o n s t r a t e d a g l a c i o f l u v i a l o r i g i n f o r most o f t h e l e v e l - b e d d e d and c r o s s - b e d d e d s and i n t h e s e d e p o s i t s and A r m s t r o n g and C l a g u e (1976) r e d e f i n e d t h e " Q u a d r a " s e d i m e n t s e s t a b l i s h i n g two new s t r a t o t y p e s . They d e f i n e d " Q u a d r a S a n d " as t h e p r o g l a c i a l u p p e r s and s a s s o c i a t e d w i t h t h e F r a s e r G l a c i -a t i o n , and t h e " C o w i c h a n Head F o r m a t i o n " as t h e l o w e r b o g , 58. swamp, f l u v i a l , e s t u a r i n e , and m a r i n e s i l t , s a n d , g r a v e l , and o r g a n i c d e p o s i t s a s s o c i a t e d w i t h t h e O l y m p i a n o n g l a c i a l i n t e r v a l . T h u s , a t Ma ry H i l l t h e " Q u a d r a S e d i m e n t s " o f A r m s t r o n g and H i c o c k ( 1975 ) may be s p l i t i n t o Quad ra Sand o f t h e F r a s e r G l a c i a t i o n i n c l u d i n g : p r o g l a c i a l and f l u v i a l s and and m i n o r g r a v e l ( u n i t 6, F i g . 3 ) ; and t h e C o w i c h a n Head F o r m a t i o n o f t h e O l y m p i a n o n -g l a c i a l i n t e r v a l i n c l u d i n g : o r g a n i c s e d i m e n t s , s i l t , s a n d , and g r a v e l ( u n i t s 2 ? , 3, and k, F i g . 3 ) . R e c e n t l y r e c e i v e d r a d i o -c a r b o n d a t e s i n d i c a t e t h a t t h e d e p o s i t s c o r r e l a t e d w i t h H i g h b u r y S e d i m e n t s a t Ma ry H i l l by A r m s t r o n g and H i c o c k ( 1975 ) a r e p r o -b a b l y p a r t o f t h e C o w i c h a n Head F o r m a t i o n and t h a t t r u e H i g h b u r y S e d i m e n t s a r e n o t e x p o s e d a t Mary H i l l ; t h e o l d e s t u n i t e x p o s e d t h e r e i s Semiahmoo? D r i f t . R a d i o c a r b o n d a t e s f r o m Mary H i l l a l s o i n d i c a t e t h e e x i s t e n c e o f a d r i f t u n i t ( u n i t 5, F i g . 3) o l d e r t h a n V a s h o n and y o u n g e r t h a n t h e C o w i c h a n Head F o r m a t i o n . T h i s u n i t has n o t been d e s -c r i b e d p r e v i o u s l y f o r m a i n l a n d B r i t i s h C o l u m b i a and may c o r r e l a t e w i t h t h e Evans C r e e k S t a d e w h i c h o c c u r r e d i n W a s h i n g t o n S t a t e , e a r l y d u r i n g t h e F r a s e r G l a c i a t i o n ( A r m s t r o n g , e t a l . , 1 9 6 5 ) • Thus a new 1 i t h o s t r a t i g r a p h i c u n i t a s s o c i a t e d w i t h t h e F r a s e r G l a c i a t i o n may be a d d e d t o t h e e s t a b l i s h e d s t r a t i g r a p h i c s u c c e s -s i o n f o r t h e F r a s e r L o w l a n d . C o r r e l a t i o n s i n t h e l o w e r C o q u i t l a m v a l l e y by A r m s t r o n g and H i c o c k ( 1976 ) a r e b e l i e v e d t o be c o r r e c t . B • C o m p o s i t e S e c t i o n and D e s c r i p t i o n o f L i t h o s t r a t i g r a p h i c U n i t s D e t a i l e d d e s c r i p t i o n s o f s e d i m e n t u n i t s e x p o s e d a t i n d i v i -d u a l s i t e s a r e g i v e n i n C h a p t e r s Two t o F o u r . The f o l l o w i n g i s 59. a c o m p o s i t e s e c t i o n o f 1 i t h o s t r a t i g r a p h i c u n i t s e x p o s e d i n t h e C o q u i1 1 a m - P o r t Moody a r e a , l i s t e d f r o m y o u n g e s t t o o l d e s t , u s i n g t h e n o m e n c l a t u r e e s t a b l i s h e d f o r t h e F r a s e r L o w l a n d . P l a t e s 1 t o 5 i l l u s t r a t e mos t o f t h e s e d i m e n t u n i t s d e s c r i b e d . Max. T h i c k n e s s (m) D e s c r i p t i o n O b s e r v e d  HOLOCENE H o l o c e n e S e d i m e n t s S e d i m e n t s d e p o s i t e d by t h e F r a s e r , ? C o q u i t l a m , and P i t t R i v e r s , by m o u n t a i n and l o w l a n d s t r e a m s , i n bogs and swamps, and by mass w a s t i n g and man. PLE ISTOCENE F r a s e r G l a c i a t i o n C a p i l a n o S e d i m e n t s R u s t y s a n d y t o s i l t y s u p r a l i t t o r a l 1 l a g g r a v e l ( F i g . 15) c o n t a i n i n g s u b a n g u l a r g r a n i t i c p e b b l e s . The m a t r i x i s m a i n l y composed o f s u b a n g u l a r g r a n i t i c d e t r i t u s , and c o n t a i n s m a r i n e s h e l l c a s t s ( F i g . 1 6 ) . Forms a m a n t l e up t o 1 m t h i c k on C a p i l a n o g l a c i o m a r i n e s e d i m e n t s and V a s h o n D r i f t . Fo rmed by s e a wave s and s p r a y r e w o r k i n g t h e s e l a t t e r d e p o s i t s . I n t e r b e d d e d y e l l o w s andy g r a v e l and 15 g r a v e l l y s a n d ( F i g . 17) c o n t a i n i n g s u b -a n g u l a r t o s u b r o u n d e d g r a n i t i c p e b b l e s . Sand i s s u b r o u n d e d t o s u b a n g u l a r , c o m -p o s e d m a i n l y o f q u a r t z and f e l d s p a r w i t h m i n o r h o r n b l e n d e and g r a n i t i c r o c k f r a g -m e n t s . O c c u r s i n s o u t h w a r d - d i p p i n g f o r e -s e t and s u b h o r i z o n t a 1 t o p s e t beds and was d e p o s i t e d i n t o t h e sea as a c o m p o s i t e d e l t a . F i n e t o medium y e l l o w s a n d , s u b h o r i - 1k z o n t a l l y t h i n l y b e d d e d , c o n t a i n i n g s u b -r o u n d e d g r a i n s composed m a i n l y o f q u a r t z and f e l d s p a r w i t h m i n o r h o r n b l e n d e , b i o -t i t e , and g r a n i t i c r o c k f r a g m e n t s . C o n -t a i n s m a r i n e s h e l l c a s t s and was d e p o s i t e d as m a r i n e l i t t o r a l and d e l t a i c s e d i m e n t s . S t o n y t o s t o n e l e s s c l a y e y s i l t c o n t a i n -i n g a b u n d a n t m a r i n e s h e l l s ( F i g . 18 ) . Bedded i n p l a c e s , i t has a b l o c k y s t r u c t u r e w i t h manganese o x i d e s t a i n i n g on j o i n t s u r f a c e s ( F i g . 1 9 ) . S t o n e s a r e m a i n l y r o u n d e d and g r a n i t i c and t h e f i n e s a r e composed o f q u a r t z and f e l d s p a r w i t h m i n o r h o r n b l e n d e and g r a n -i t i c r o c k f r a g m e n t s . M a r i n e and g l a c i o m a r i n e d e p o s i t s . GSC 2177 ( s he 11s- 12 , 000*100) c o l l e c t e d f r o m t h i s l a y e r . M a j o r U n c o n f o r m i t y Va shon D r i f t T i l l ( F i g . 2 0 ) , a t l e a s t t h r e e s h e e t s r e p r e s e n t i n g l o c a l i c e a d v a n c e s , s e p a r a t e d by o u t w a s h g r a v e l and s a n d . M o s t l y l o d g e -m e n t , bu t p r o b a b l y i n c l u d e s f l o w t i l l . C o n t a i n s l e n s e s o f p o n d e d , l a m i n a t e d s t o n y s i l t . C o n t a i n s s u b r o u n d e d t o s u b a n g u l a r g r a n i t i c p e b b l e s t o b o u l d e r s up t o 5 d i a . ( F i g . 21 ) . M a t r i x g r a i n s a r e a n g u l a r f a c -e t e d , and m a i n l y composed o f q u a r t z and f e l d s p a r w i t h m i n o r h o r n b l e n d e , e p i d o t e , and g r a n i t i c r o c k f r a g m e n t s . Sandy g r a v e l and g r a v e l l y s a n d , u n d e r , b e t w e e n , and o v e r Va shon t i l l s h e e t s , c o n -t a i n i n g t h i n l y bedded s i l t y f i n e sand l e n s e s . E x t r e m e l y v a r i a b l e i n t e x t u r e and s t r u c t u r e s ; f r o m f o r e s e t c o b b l e g r a v e l beds ( F i g . 22) t o f a u l t e d and c o n t o r t e d s and and g r a v e l d i s p l a y -i n g i c e - c o n t a c t f e a t u r e s ( F i g . 23 ) - C o n t a i n s s u b r o u n d e d t o s u b a n g u l a r , f r o s t e d and c o m -po sed m a i n l y o f q u a r t z and f e l d s p a r w i t h m i n o r h o r n b l e n d e , e p i d o t e , b i o t i t e , and g r a n i t i c r o c k f r a g m e n t s . Ou twash d e p o s i t s ; g r a d e s downward i n t o Quad ra S a n d . M a j o r U n c o n f o r m i t y Q u a d r a Sand Medium t o f i n e sand ( F i g s . 2k, 25, 27, 28) c o n t a i n i n g s andy s i l t i n t e r b e d s ; g r a v e l l e n s e s and i n t e r b e d s ; s c a t t e r e d s t o n e s and s t o n e c l u s -t e r s ; and d e t r i t a l c o a l and p e a t c l a s t s . G e n e r -a l l y s u b h o r i z o n t a l l y b e d d e d , c r o s s - b e d d e d ; i n p l a c e s r i p p l e d , f a u l t e d . C o n t a i n s s u b r o u n d e d t o s u b a n g u l a r g r a n i t i c p e b b l e s ; sand g r a i n s a r e s u b a n g u l a r t o s u b r o u n d e d , s l i g h t l y f r o s t e d and m a i n l y c ompo sed o f q u a r t z and f e l d s p a r w i t h m i n o r h o r n b l e n d e , e p i d o t e , b i o t i t e , and g r a n -i t i c r o c k f r a g m e n t s . D e p o s i t e d as p r o g l a c i a l o u t w a s h , b u t may i n p a r t be f l u v i a l d e p o s i t s . G_SC 2\3k ( F i g . 26) (wood i n p e a t 1 a y e r - - 1 8 ,600 -190) and 2203 ( w o o d - - 2 1 , 6 0 0 * 2 0 0 ) w e r e c o l l e c t e d f rom t h i s u n i t . M a j o r U n c o n f o r m i t y Coqu i 11 am D r i f t S t o n y c l a y e y s i l t d i a m i c t o n ( F i g s . 29, 30) c o n t a i n i n g m a r i n e s h e l l f r a g m e n t s . S t o n e s a r e a m i x t u r e o f s u b r o u n d e d g r a n i t i c , v o l c a n i c , c h e r t , q u a r t z i t e , and p e l i t i c r o c k t y p e s ; f i n e s a r e m a i n l y composed o f s u b a n g u l a r , f a c e t e d g r a i n s o f q u a r t z and f e l d s p a r w i t h m i n o r h o r n b l e n d e and a r g i l l a c e o u s , a m p h i b o 1 i t i c ? , and c h e r t y r o c k f r a g m e n t s . T h i s i s t h e o n l y u n i t e x p o s e d i n t h e C o q u i11 a m - P o r t Moody a r e a t h a t c o n t a i n s a s i g n i -f i c a n t p r o p o r t i o n o f C a s c a d e s M t n s , - d e r i v e d m a t -e r i a l . P r o b a b l y g l a c i o m a r i n e d e p o s i t s , b u t may i n p a r t be t i l l . M a j o r U n c o n f o r m i t y Q u a d r a ? Sand Med ium s a n d ( F i g . 30) c o n t a i n i n g g r a v e l l e n s e s , s c a t t e r e d s t o n e s and s t o n e c l u s t e r s . C r o s s - b e d d e d and f a u l t e d , c o n t a i n i n g d e t r i t a l c o a l and p e a t c l a s t s . C o n t a i n s s u b r o u n d e d t o s u b a n g u l a r g r a n i t i c p e b b l e s and s u b a n g u l a r t o s u b r o u n d e d med ium s and m o s t l y composed o f q u a r t z and f e l d s p a r w i t h m i n o r h o r n b l e n d e , e p i d o t e , and g r a n i t i c r o c k f r a g m e n t s . P r o -b a b l y d e p o s i t e d a s p r o g l a c i a l o u t w a s h b u t may i n p a r t be f l u v i a l d e p o s i t s a s s o c i a t e d w i t h t h e C o w i c h a n Head F o r m a t i o n . M a j o r U n c o n f o r m i t y O l y m p i a N o n g l a c i a l I n t e r v a l C o w i c h a n Head F o r m a t i o n R u s t y s a n d y g r a v e l g r a d i n g downward i n t o s i l t y f i n e s and ( F i g . 31 ) , b o t h c o n t a i n i n g w o o d - b e a r i n g o r g a n i c s i l t l a y e r s . Wood l a y e r s c o n t a i n l o g s up t o k m l o n g and 30 cm d i a . S u b h o r i z o n t a 1 1 y b e d d e d ; c o n t a i n s s u b r o u n d e d g r a n i t i c p e b b l e s and s u b r o u n d e d t o s u b a n g u l a r s and g r a i n s m a i n l y composed o f q u a r t z f e l d s p a r w i t h m i n o r b i o t i t e , h o r n b l e n d e , e p i d o t e , and g r a n i t i c r o c k f r a g m e n t s . P r o b a b l y f l u v i a l and swamp d e p o s i t s . GSC 2273 (wood f r o m o r g a n i c s i 1 t - - 2 5 , 800*31 0 ) . 2277 (wood f r o m g r a v e l - - 2 6 , 0 0 0 * 3 1 0 ) , 2191 (wood f r o m g r a v e l - - 2 6 . 2 0 0 * 3 2 0 ) , and 2217 (wood f r o m o r g a n i c s i 1 t - - 2 6 , 9 0 0 * 3 2 0 ) w e r e c o l l e c t e d f r o m t h i s u n i t . Q u a d r a ? S a n d , b e l o w C o q u i t l a m D r i f t may i n p a r t b e l o n g t o t h i s u n i t . I n t e r b e d d e d p e a t , s a p r o p e l , and s i l t y f i n e s a n d s e q u e n c e ( F i g s . 33, 34, 35) c o n t a i n -i n g f o s s i l l o g s up t o 3 m l o n g and 30 cm d i a . F o s s i l l e a v e s , i n s e c t s , and d i a t o m s a l s o f o u n d i n t h i s u n i t . S i l t y sand i s s u b r o u n d e d t o s u b a n g u l a r and i s m a i n l y composed o f q u a r t z and f e l d s p a r w i t h m i n o r b i o t i t e , h o r n b l e n d e , e p i d o t e , and g r a n i t i c r o c k f r a g m e n t s . D e p o s i t e d as bog and swamp d e p o s i t s . GSC 2263 (wood f r o m p e a t - - 2 7 , 0 0 0 * 4 9 0 ) , 2107 ( F i g . 35) (wood f r o m p e a t - - 2 7 , 4 0 0 * 4 2 0 ) , 2139 (wood f r o m p e a t - - 2 8 , 2 0 0 *200) , and 2140 ( s a p r o p e 1--29 , 600*200) we re c o l l e c t e d f r o m t h i s u n i t . C o w i c h a n Head F o r m a t i o n ? S t o n y o r g a n i c c o l l u v i u m , c o m p r i s e d o f a s t o n y , w o o r - b e a r i n g s i l t - r i c h p h a s e and a s t o n y , w o o d - b e a r i n g d e n s e o r g a n i c - r i c h p h a s e ( F i g . 32) c o n t a i n i n g f o s s i l l e a v e s and i n s e c t s ; b o t h a r e p r o d u c t s o f mass w a s t i n g . S t o n e s f r o m t h i s u n i t a r e m o s t l y s u b r o u n d e d and g r a n i t i c . GSC 2137 (wood f r o m t h e o r g a n i c - r i c h p h a s e - -4 0 , 2 0 0 * 4 3 0 ) , 2167 (wood f r o m t h e s i l t - r i c h p h a s e - - 4 0 , 5 0 0 * 1 7 0 0 ) w e r e c o l l e c t e d f r o m t h i s u n i t . M a j o r U n c o n f o r m i t y M a j o r G l a c i a t i o n Semiahmoo? D r o f t R h y t h m i c a l l y l a m i n a t e d s i l t ( F i g . 39) c o n t a i n i n g s c a t t e r e d s u b r o u n d e d g r a n i t i c s t o n e s . The s i l t i s c omposed o f a n g u l a r g r a n i t i c d e t r i t u s . P r o b a b l y g 1 a c i o 1 a c u s t r i n e d e p o s i t s . GSC 2120 (wood - - >48 ,000 ) and QL -194 ( S t r u i v e r , U. o f W a s h . , wood- ->62 ,000) w e r e c o l l e c t e d f r o m t h i s u n i t . M a s s i v e s t o n y c l a y e y s i l t ( F i g s . 36, 37) c o n t a i n i n g s c a t t e r e d s u b r o u n d e d g r a n i t i c s t o n e s . W e a t h e r s t o a b l o c k y s t r u c t u r e . F i n e s a r e made o f q C a r i r a n d 3 ? ' ^ 0 r 0 c k . f l o u r composed m a i n l y o r q u a r t z and f e l d s p a r w i t h m i n o r h o r n b l e n d e e p i d o t e , and g r a n i t i c r o c k f r a g m e n t s P r o b ^ h l v g l a c o m a r l n e d e p o s i t s , bu t m a y ' ? " ol'rr l l ^ l Y may i n p a r t be t i l l Sandy g r a v e l and g r a v e l l y s and ( F i g . 36 ) , s u b h o r i z o n t a 1 1 y bedded and c r o s s - b e d d e d , d e p o s -i t e d b e l o w , b e t w e e n , and a b o v e Semiahmoo? t i l l s . C o n t a i n s s u b r o u n d e d t o s u b a n g u l a r g r a n i t i c p e b b l e s and s u b a n g u l a r , s l i g h t l y f r o s t e d s a n d g r a i n s a r e m o s t l y composed o f q u a r t z and f e l d -s p a r w i t h m i n o r h o r n b l e n d e , b i o t i t e , e p i d o t e , and g r a n i t i c r o c k f r a g m e n t s . Ou twash d e p o s i t s . A t Mary H i l l t h i s u n i t u n d e r l i e s t h e m a s s i v e g l a c i o m a r i n e ? u n i t and c o n t a i n s l e n s e s o r c l a s t s o f s t o n y c l a y e y s i l t , p o s s i b l y p i c k e d up f r o m a l o w e r g l a c i o m a r i n e u n i t . Lodgement t i l l ( F i g s . 36, 3 8 ) . a t l e a s t two l a y e r s r e p r e s e n t i n g l o c a l i c e a d v a n c e s , b e t w e e n o u t w a s h s and and g r a v e l . C o n t a i n s l e n s e s o f p o n d e d , l a m i n a t e d s t o n y s i l t . P e b b l e s a r e m o s t l y s u b r o u n d e d t o s u b a n g u l a r and g r a n i t i c . M a t r i x v a r i e s f r o m a n g u l a r , f a c e t e d , s a n d y s i l t and i s m a i n l y c omposed o f q u a r t z and f e l d s p a r w i t h m i n o r h o r n b l e n d e , e p i d o t e , and g r a n i t i c r o c k f r a g m e n t s . Med ium t o f i n e s and e x p o s e d a t t h e P o r t Moody d i s p o s a l s i t e ( F i g . kO) c o n t a i n i n g s i l t y f i n e s and i n t e r b e d s , g r a v e l l e n s e s and i n t e r b e d s , and s c a t t e r e d s t o n e s and s t o n e c l u s t e r s . G e n e r -a l l y s u b h o r i z o n t a 1 1 y b e d d e d , e x t e n s i v e l y c r o s s -b e d d e d , i n p l a c e s r i p p l e d , f a u l t e d . C o n t a i n s g r a n i t i c p e b b l e s and s and i s s u b a n g u l a r t o s u b r o u n d e d , s l i g h t l y f r o s t e d and m o s t l y c ompo sed o f q u a r t z and f e l d s p a r w i t h m i n o r h o r n b l e n d e , b i o t i t e , e p i d o t e , and g r a n i t i c r o c k f r a g m e n t s . P r o b a b l y p r o g l a c i a l o u t w a s h d e p o s i t s , b u t may i n p a r t be f l u v i a l . The w r i t e r c o n s i d e r s t h i s t o be t h e Semiahmoo? e q u i v a l e n t o f Quad ra Sand ( d e p o s i t e d d u r i n g t h e F r a s e r G l a c i a t i o n ) . M a j o r U n c o n f o r m i t y M a j o r N o n g l a c i a l I n t e r v a l H i g h b u r y ? S e d i m e n t s R u s t y s i l t , f i n e sand and m i n o r g r a v e l ( F i g s . A l . 4 2 , 43) e x p o s e d i n t h e l o w e r C o q u i t -lam R i v e r v a l l e y . S u b h o r i z o n t a 1 1 y t h i n l y b e d d e d , c r o s s - b e d d e d , and r i p p l e d ; c o n t a i n s a w o o d -b e a r i n g o r g a n i c s i l t l a y e r . P e b b l e s a r e m a i n l y s u b r o u n d e d and g r a n i t i c and t h e s u b r o u n d e d t o s u b a n g u l a r s a n d and s i l t g r a i n s a r e m o s t l y composed o f q u a r t z and f e l d s p a r w i t h m i n o r h o r n b l e n d e , b i o t i t e , e p i d o t e , and g r a n i t i c r o c k f r a g m e n t s . P r o b a b l y f l u v i a l f l o o d -p l a i n s e d i m e n t s . GSC 2 0 9 4 - 2 (wood f r o m o r g a n i c s i 1 t - - > 4 9 , 0 0 0 ) was c o l l e c t e d f r o m t h i s u n i t . M a j o r U n c o n f o r m i t y M a j o r G l a c i a t i o n ? Wes 11ynn D r i f t ? S e m i - i m p e r v i o u s c o b b l e g r a v e l ( F i g s . 4 3 , 23 44) e x p o s e d i n t h e l o w e r C o q u i t l a m R i v e r v a l l e y , c o n t a i n i n g m i n o r s and l e n s e s . S u b h o r i z o n t a 1 1 y b e d d e d , c r u d e l y c r o s s - b e d d e d ; c o n t a i n s o v e r 90% r o u n d e d t o s u b r o u n d e d g r a n i t i c p e b b l e s and c o b b l e s w i t h m i n o r m a t r i x o f medium t o c o a r s e s u b a n g u l a r s and g r a i n s m o s t l y composed o f q u a r t z and f e l d s p a r w i t h m i n o r h o r n b l e n d e , b i o t i t e , e p i d o t e , and g r a n i t i c r o c k f r a g m e n t s . P r o b a b l y g l a c i o f l u v i a l d e p o s i t s . T i l l and G l a c i o m a r i n e D e p o s i t s A r m s t r o n g and Brown (1954 ) d e s c r i b e d g l a c i o m a r i n e s e d i m e n t s e x p o s e d i n t h e F r a s e r L o w l a n d and d i s c u s s e d t h e i r o r i g i n . They s u g g e s t e d t h a t t h e t i 1 1 -1 i k e " s t o n y c l a y s " w e r e f o r m e d by s t o n e s d r o p p i n g i n t o s e a - f l o o r muds f r o m f l o a t i n g i c e , r a t h e r t h a n as t i l l d e p o s i t e d d i r e c t l y u n d e r g l a c i e r i c e , a s was b e l i e v e d by w o r k e r s b e f o r e t h e m . Today t h i s t h e o r y i s w i d e 1 y a c c e p t e d . V a s h o n t i l l and C a p i l a n o g l a c i o m a r i n e s e d i m e n t s , b o t h d e p o s i t e d d u r i n g t h e F r a s e r G l a c i a t i o n , a r e e a s i l y d i s t i n g u i s h -a b l e i n t h e C o q u i1 1 a m - P o r t Moody a r e a . V a s h o n t i l l i s g r e y t o d u l l o r a n g e ( o x i d i z e d ) , v e r y s t o n y , common ly c o m p a c t and p l a t y . C a p i l a n o g l a c i o m a r i n e s e d i m e n t s a r e d a r k b l u e - g r e y , c o n t a i n i n g few s c a t t e r e d s t o n e s , and a r e n o t c o m p a c t e d . They have a c h a r -a c t e r i s t i c b l o c k y s t r u c t u r e w i t h manganese o x i d e s t a i n i n g on j o i n t s u r f a c e s and common ly c o n t a i n f o s s i l m a r i n e s h e l l s and 65. 15. S u p r a l i t t o r a l l ag gravel grading downward i n to dark grey Vashon lodgement t i l l , Mary H i l l ( sect ion N, F i g . 2 ) . 16. She l l cast from s u p r a l i t t o r a l l a g gravel i n F i g . 15. 17. Foreset and topset bedded Capi lano r a i s ed d e l t a i c sand and g r a v e l , Coquitlam v a l l e y ( p i t B, F i g . 6 ) . 18. F o s s i l i f e r o u s marine c layey s i l t , Coquitlam v a l l e y ( sect ion C5, F i g . 6 ) . 19. Blocky Capilano g lac iomarine stony c layey s i l t o v e r l y i n g p l a t y Vashor t i l l , Mary H i l l (near sec t i on L, F i g . 2 ) . 20. Compact, bouldery Vashon t i l l , Mary H i l l ( sect ion E, F i g . 2 ) . Plate 1: Figs. 15 to 20. 21. Polished, grooved, striated, and chattel-marked granitic erratic resting on Vashon t i l l , Mary Hi l l (near section E, Fig. 2). 22. Foreset bedded Vashon outwash sandy gravel, Mary Hi l l (section K, Fig. 2). 23. Contorted ice contact Vashon sand, gravel, and flow t i l l , Coquitlam valley (section G2, Fig. 6). Drs. J.E.Armstrong and J . J . Clague for scale. 23 24. Cross-bedded Quadra Sand (large scale), Mary Hi l l (section D, Fig. 2). J 25. Cross-bedded Quadra Sand (small scale), Mary Hi l l (section D, Fig. 2). 26. Thin peat layer (under boots) overlying Semiahmoo? stony s i l t , Mary Hi l l (section D, Fig. 2). Wood from peat dated as 18,600 + 190 yr. B.P. Plate 2- Figs. 21 to 26. 67. Th in ly bedded Quadra Sand underly ing Vashon D r i f t , Coquitlam v a l l e y ( sect ion F4, F ig . 6 ) . P ick f o r sca le i n centre of photo. 28. Load ca s t s , b a l l and p i l l o w s t r u c t u r e s , and convoluted bedding in s i l t y f i n e sand i n F i g . 27. 29. Massive stony Coquitlam D r i f t , Mary H i l l ( sec t ion J , F i g . 2 ) . L to R, Drs. J . J . Clague, J.M. Ryder, R.J. Fu l t on , and J .E . Armstrong f o r s ca l e . 30. Sharp angular contact: Coquitlam D r i f t o v e r l a i n by Quadra Sand and under la in by sand, e i t h e r Ouadra or pa r t o f the Cowichan Head Formation, Mary H i l l ( sect ion J , F i g . 2 ) . P ick f o r s ca le in centre of photo. Cowichan Head f l u v i a l gravel and sand unconformably ove r l y i ng Cowichan Head? dense stony organic co l luv ium (dark, lower r i g h t i n photo), Mary H i l l ( sect ion C, F i g . 2). B l u f f i s 10 m h iqh. Cowichan Head? stony organic co l l uv ium, Mary H i l l ( sect ion A, F i g . 2 ) . Dr. R.J. Fulton f o r s ca l e . Wood from F u l t o n ' s s hou lde r - l eve l dated as 40,200 + 430 y r . B.P. 31 32 Plate 3: Figs. 27 to 32. 33. Cowichan Head? wood-rich organic s i l t layer between quadra? laminated s i l ty fine sand (above) and Semiahmoo? t i l l and outwash gravel (below) Port Moody (section C, Fig. 10). 34. Buried landscape: Cowichan Head peat layer containing a spruce stump (below boulder 1n centre of photo) abuts against the slope formed on Cowichan Head? stony organic colluvium (on which Dr. J.E. Armstrong is standing), Mary Hi l l (section B, Fig. 2). 35. Fossil spruce stump in peat layer in Fig. 34. Stump dated as 27,400 ± 420 yr. B.P. Stony organic colluvium can be seen below at the base of the shovel handle. Semiahmoo? Drift, Coquitlam valley. Two lodqement t i l l s separated by outwash gravel are overlain by outwash gravel and sand and then by massive glaciomarine? stony clayey s i l t ; Vashon Drift overlies the stony s i l t (section F3, Fig. 6). Pick for scale at the top of the upper t i l l , lower left centre of photo. 37. Semiahmoo? glaciomarine? stony clayey s i l t in Fig. 36. 38. Semiahmoo? platy lodgement t i l l 1n Fig. 36. H 38 Plate 4: Figs. 33 to 38. 69. 39. Semiahmoo? g l a c i o l a c u s t r i n e rhy thmica l l y laminated stony s i l t , Mary H i l l (near sec t i on M, F i g . 2). 40. Semiahmoo? p rog l a c i a l sand, Port Moody ( sect ion B, F i g . 10). 41. Highbury? f l u v i a l t h i n l y bedded sand, s i l t , and minor gravel ( l i g h t and dark s t r i p e s ) between Semiahmoo? outwash gravel and sand (above) and Westlynn? outwash? gravel (below), Coquitlam v a l l e y ( sect ion F3, F i g . 6 ) . 42. R ipp led , t h i n l y bedded Highbury? sand in F i g . 41. Dr. J . E . Armstrong f o r s ca l e . 43. Contact: Highbury? t h i n l y bedded sand, s i l t , and minor gravel unconformably o ve r l y i n g Westlynn? outwash? Plate 5: Figs. 39 to 44. s h e l l c a s t s . D i f f e r e n c e s b e t w e e n p r e - V a s h o n t i l l s and g l a c i o m a r i n e s e d i r m e n t s , h o w e v e r , a r e no t as o b v i o u s ( F i g s . 36, 37, 38) and t h e o l d e r g l a c i o m a r i n e u n i t s may i n p a r t be t i l l . Where d a r k b l u e -g r e y f i n e s e d i m e n t s ( i n p l a c e s bedded ) c o n t a i n i n g f e w , w i d e l y s c a t t e r e d , r o u n d e d s t o n e s and b l o c k y s t r u c t u r e a r e e n c o u n t e r e d ( F i g . 1 9 ) , t h e y a r e c o n s i d e r e d t o be g l a c i o m a r i n e . Where a g r e y t o d u l l o r a n g e ( o x i d i z e d ) , c o m p a c t d i a m i c t o n c o n t a i n i n g a b u n d a n t s u g a n g u l a r t o s u b r o u n d e d s t o n e s i s f o u n d w i t h a s andy t o s i l t y m a t r i x , i t i s c o n s i d e r e d t o be t i l l ( F i g s . 1 5 , 2 0 ) . T h e s e two e x a m p l e s a r e t e x t u r a l end members i n a t r a n s i t i o n a l s e r i e s , b e t w e e n w h i c h m a c r o s c o p i c d i f f e r e n t i a t i o n o f t i l l and g l a c i o m a r i n e d e p o s i t s i s v e r y d i f f i c u l t . G r a i n s i z e a n a l y s e s o f t h e m a t r i x i n t h e two s e d i m e n t t y p e s a r e p l o t t e d i n F i g . 15 -I t i l l u s t r a t e s t h a t t h e g l a c i o m a r i n e s e d i m e n t s g e n e r a l l y c o n t a i n a f i n e r m a t r i x t h a n t h e t i l l s . Some o v e r l a p o c c u r s , h o w e v e r , and i s t h o u g h t t o r e s u l t f r o m g l a c i e r i c e o v e r r i d i n g g l a c i o -m a r i n e s e d i m e n t s , d i s t u r b i n g and m i x i n g them w i t h t i l l . B o t h t i l l and g l a c i o m a r i n e p e b b l e s a r e g e n e r a l l y r o u n d e d i n c o n t r a s t t o t h e a n g u l a r m a t r i x g r a i n s . T h i s was p r o b a b l y c a u s e d by g l a c i e r i c e a d v a n c i n g o v e r and i n c o r p o r a t i n g i t s own r o u n d e d o u t w a s h g r a v e l s (and o l d e r g r a v e l s ) and t h e n r e d e p o s i t -i n g them as t h e f r a m e w o r k g r a i n s i n t i l l o r a s d r o p s t o n e s i n g l a c i o m a r i n e d e p o s i t s . T h e o r e t i c a l l y l o d g e m e n t t i l l p e b b l e s s h o u l d be s t r o n g l y o r i e n t e d i n t h e d i r e c t i o n o f i c e movement and g l a c i o m a r i n e p e b b l e s s h o u l d no t be o r i e n t e d , h a v i n g been r a n d o m l y d r o p p e d S A N D S A N D MATRIX GRAIN S IZE DISTRIBUTION OF T I L L AND GLACIOMARINE DEPOSITS: Fig.45 A. PLOT OF ANALYSES B. AREAS OF GRAIN S IZE DISTRIBUTION 72. t o t h e sea f l o o r by f l o a t i n g i c e . P e b b l e f a b r i c a n a l y s e s done on b o t h t y p e s o f s e d i m e n t i n t h i s s t u d y ( F i g . 16 , C h a p t e r S i x ) a r e , h o w e v e r , i n c o n c l u s i v e . T h i s a l s o s u g g e s t s t h a t some o f t h e p r e - V a s h o n g l a c i o m a r i n e d e p o s i t s have been d i s t u r b e d by o v e r -r i d i n g i c e and m i x e d w i t h t i l l . The o n l y c o n c l u s i v e e v i d e n c e o f a g l a c i o m a r i n e o r i g i n f o r a s e d i m e n t u n i t a p p e a r s t o be t h e o c c u r r e n c e o f s c a t t e r e d s t o n e s and m a r i n e s h e l l s , i n n e a r t o g r o w t h p o s i t i o n , embedded i n i t . Such i s t h e c a s e f o r t h e C a p i l a n o g l a c i o m a r i n e s e d i m e n t s , i n w h i c h u n d i s t u r b e d p e l e c y p o d s and b a r n a c l e s s t i l l a t t a c h e d t o p e b b l e s o c c u r , b o t h c o m p l e t e l y i n f i l l e d and s u r r o u n d e d by c l a y e y s i l t . H o w e v e r , C a p i l a n o g l a c i o m a r i n e d e p o s i t s have n o t been o v e r r i d d e n o r d i s t u r b e d by g l a c i e r i c e . 73. CHAPTER S I X : QUATERNARY HISTORY F r a s e r Low l a n d A r m s t r o n g (1965, 1975a, b, and o t h e r p a p e r s i n p r e s s and p r e p . ) has w r i t t e n a b o u t t h e Q u a t e r n a r y h i s t o r y o f u n c o n s o l i -d a t e d s e d i m e n t s e x p o s e d i n t h e F r a s e r L o w l a n d , i n w h i c h t h e Coqu i11 a m - P o r t Moody a r e a i s l o c a t e d . He c o n c l u d e s t h a t d u r -i n g W i s c o n s i n and p r o b a b l y e a r l i e r t i m e t h e L o w l a n d was s u b j e c -t e d t o r e p e a t e d g l a c i a t i o n s s e p a r a t e d by n o n g l a c i a l i n t e r v a l s . Each m a j o r g l a c i a t i o n went t h r o u g h an a d v a n c e s t a g e i n v o l v i n g c o a l e s c i n g p i e d m o n t g l a c i e r s , a maximum when t h e i c e r e a c h e d a t h i c k n e s s o f a t l e a s t 1,800 m and o v e r r o d e much o f t h e a d j o i n -i n g m o u n t a i n o u s a r e a s , and a r e t r e a t ( d e g 1 a c i a t i o n ) s t a g e when i c e m a i n l y o c c u p i e d v a l l e y s and arms o f t h e sea b e f o r e r e a d v a n -c i n g l o c a l l y as s u r g i n g g l a c i e r s . Each m a j o r g l a c i a t i o n was a c c o m p a n i e d by i s o s t a t i c , e u s t a t i c , and p r o b a b l y t e c t o n i c a d j u s t ments r e s u l t i n g i n r e p e a t e d s e a - l e v e l c h a n g e s up t o a t l e a s t 200 m. As a r e s u l t o f t h i s c o m p l e x g e o l o g i c a l h i s t o r y v e r y t h i c k Q u a t e r n a r y s e d i m e n t s a t l e a s t 300 m t h i c k , o f w i d e l y d i v e r s i f i e d o r i g i n i n c l u d i n g m a r i n e , n o n - m a r i n e , and g l a c i a l , we re d e p o s i t e d and e r o d e d . A r m s t r o n g ' s c o m p o s i t e s t r a t i g r a p h i c s e c t i o n o f t h e F r a s e r L o w l a n d i s i n c o r p o r a t e d i n T a b l e II f o r V a shon and o l d e r d e p o s i t s . A r m s t r o n g ( i n p r e s s ) mapped d e p o s i t s r e p r e s e n t i n g a t l e a s t t h r e e g l a c i a t i o n s i n t h e L o w l a n d , i n c l u d i n g t h r e e s t a d e s i n t h e l a s t g l a c i a t i o n : V a s h o n , F o r t L a n g l e y , and Sumas. He d e s c r i b e s t h e F o r t L a n g l e y a n d . t h e . ( l a s t ) Sumas i c e a d v a n c e s as p i e d m o n t g l a c i e r s a d v a n c i n g f r o m t h e e a s t and n o r t h e a s t and t e r m i n a t i n g 74. i n t h e s ea f o r much o f t h e i r h i s t o r i e s ( l i k e M a l a s p i n a g l a c i e r o f A l a s k a ) a b o u t 15 km e a s t o f t h e C o q u i1 1 a m - P o r t Moody a r e a . F o r t L a n g l e y m a r i n e and g l a c i o m a r i n e s e d i m e n t s w e r e a l s o d e p o -s i t e d b e f o r e t h e Sumas i c e a d v a n c e . To t h e w e s t o f t h e Sumas i c e t e r m i n u s C a p i l a n o m a r i n e and g l a c i o m a r i n e s e d i m e n t s we re l a i d down d u r i n g p o s t - V a s h o n t i m e . A c c o r d i n g t o A r m s t r o n g , Sumas and F o r t L a n g l e y F o r m a t i o n d e p o s i t s e x t e n d w e s t w a r d t o a p o i n t a p p r o x i m a t e l y 5 km e a s t o f t h i s s t u d y a r e a , i n w h i c h C a p i l a n o s e d i m e n t s a r e t h e o n l y p o s t - V a s h o n P l e i s t o c e n e d e p o -s i t s t o o c c u r . D u r i n g t h i s s t u d y t h e w r i t e r d i s c o v e r e d a d r i f t u n i t t h a t p r o b a b l y r e p r e s e n t s a f o u r t h s t a d e i n t h e l a s t g l a c i a t i o n , e a r l i e r t h a n t h e V a s h o n S t a d e , and d e s i g n a t e s i t as C o q u i t l a m D r i f t . T h i s may be a c o r r e l a t i v e o f t h e Evans C r e e k S t a d e f o u n d i n n o r t h w e s t e r n W a s h i n g t o n . A r m s t r o n g and H i c o c k ( i n p r e p . ) d i s c u s s t h i s d r i f t u n i t more e x t e n s i v e l y i n a j o i n t p a p e r . B. C o q u i t l a m P o r t - M o o d y A r e a W e s t l y n n D r i f t ? , o u t w a s h ? g r a v e l , i s t h e o l d e s t Q u a t e r n a r y s e d i m e n t e x p o s e d i n t h e a r e a and was d e p o s i t e d more t h a n 6 2 , 0 0 0 y e a r s a g o , p r o b a b l y by s o u t h w a r d - f 1 o w i n g m e l t w a t e r s t r e a m s ( F i g . *T7G ) , u n d e r a c l i m a t e c o o l e r t h a n t h a t o f t o d a y , d e b o u c h i n g f r o m a g l a c i e r f u r t h e r n o r t h up t h e C o q u i t l a m v a l l e y i n t h e C o a s t M o u n t a i n s ( F i g . ^|-8H). An e r o s i o n a l p e r i o d f o l l o w e d and a l a n d -s c a p e r e s u l t i n g f r o m a r a d i c a l c h a n g e i n s e d i m e n t r e g i m e d e v e l o p e d . The c l i m a t e p r o b a b l y warmed and n o n g l a c i a l s t r e a m s f l o w e d n o r t h w a r d ( F i g . ^ 7 F ) i n t o t h e l o w e r C o q u i t l a m v a l l e y d e p o s i t i n g H i g h b u r y ? f l u v i a l s e d i m e n t s more t h a n 4 9 , 0 0 0 and p r o b a b l y more 122°50 49°20'. 49°15'H LEGEND Inferred d i r e c t i o n o f i c e movement, based on: Strong p r e f e r r e d pebble (long axis) o r i e n t a t i o n s Weak p r e f e r r e d pebble (long axis) o r i e n t a t i o n s J|J No p r e f e r r e d pebble (long axis) o r i e n t a t i o n s A CAPILANO GLACIOMARINE SEDIMENTS B VASHON TILL C COQUITLAM GLACIOMARINE? SEDIMENTS D SEMIAHMOO? TILL E SEMIAHMOO? GLACIO MARINE SEDIMENTS eg average o f 3 analyses: strong p r e f e r r e d 3/ pebble o r i e n t a t i o n i n f e r r i n g i c e movement towards 200°. *Data condensed from F i g s . 5A, 8A, and 12A. Ratio of long/intermediate axis lengths f o r most pebbles was 1.5 to 2.0. 90% of a l l pebble long axes dipped l e s s than 25°, and 57% dipped less than 10o ; 43% dipped northward, against the main d i r e c t i o n of i c e movement FIG. 46 INFERRED ICE MOVEMENT DIRECTIONS FROM PEBBLE FABRICS*IN EXPOSED PLEISTOCENE GLACIAL DIAMICTONS: COQUITLAM - PORT MODDY AREA, BRITISH COLUMBIA 122°50' 122°45' A CAPILANO SEDIMENTS B VASHION DRIFT C QUADRA SAND D COWICHAN HEAD FORMATION *Data condensed from Figs. 5B, 8B, and 12B E SEMIAHMOO? DRIFT F HIGHBURY? SEDIMENTS G WESTLYNN DRIFT? eg. ; average of 3 analyses: 3/ inferred direction of / paleostream flow (200°) Fig. 47: PALEOCURRENT DIRECTIONS IN EXPOSED PLEISTOCENE SAND AMD GRAVEL: COQUITLAM-PORT MOODY AREA, BRITISH COLUMBIA 122°50' 122°45' |49 20'-f> U9 15' A CAPILANO SEDIMENTS B VASHON DRIFT C QUADRA SAND D COQUITLAM DRIFT E COWICHAN HEAD FORMATION F SEMIAHMOO? DRIFT G HIGHBURY? SEDIMENTS H WESTLYNN DRIFT? % pebbles having ,QQ Cascade Mtns. source '— (eastern provenance) 100 1 eg. 3^ average of 3 analyses: 80% of the pebbles have a Coast Mtns. source (northern provenance) and 20% have a Cascade Mtns. source (eastern provenance) % pebbles having Coast Mtns. source (northern provenance) * Data condensed from Figs. 5C, 8C, and 12C. GEOLOGY; PEBBLE SOURCE AKEAS. ick et. al., 1973: G.S.C. Open File LEGEND; see Fig.5D F i g . 48 : PEBBLE PROVENANCE* OF EXPOSED PLEISTOCENE SEDIMENTS: COQUITLAM - PORT MOODY AREA, BRITISH COLUMBIA. 78. t h a n 6 2 , 0 0 0 y e a r s a g o . P e b b l e p r o v e n a n c e ( F i g . 4 8 G ) s u g g e s t s t h a t e i t h e r t h e n o r t h e a s t w a r d s t r e a m f l o w was a l o c a l p h e n o -menon i n s t r e a m meander bends o r b a c k e d d i e s w h e r e t h e f l o w was a g a i n s t a m a i n , s o u t h w a r d , s t r e a m f l o w ; o r t h a t t h e g r a v e l was t r a n s p o r t e d by a m a i n n o r t h e a s t w a r d s t r e a m f l o w w h i c h r e w o r k e d o l d e r s e d i m e n t s t h a t we re d e p o s i t e d by s t r e a m s f l o w i n g s o u t h w a r d o u t o f t h e C o a s t M o u n t a i n s . S t r e a m s p r o b a b l y f l o w / o f f t h e C o a s t M o u n t a i n s and d i v e r t e d up t h e l o w e r r e a c h e s o f t h e C o q u i t l a m v a l l e y , d e p o s i t i n g m a t e r i a l o f n o r t h e r n p r o v e n a n c e and r e w o r k i n g o l d e r s e d i m e n t s . D u r i n g t h i s t i m e a t h i n o r g a n i c s i l t l a y e r c o n t a i n i n g p i e c e s o f s p r u c e wood was f o r m e d . S h a r p p r o t u b e r -a n c e s on t h e wood s u g g e s t t h a t i t was n o t t r a n s p o r t e d v e r y f a r f r o m i t s g r o w t h p o s i t i o n . A p e r i o d o f e r o s i o n f o l l o w e d and a . l a n d s c a p e was d e v e l o p e d on H i g h b u r y ? S e d i m e n t s . The c l i m a t e c o o l e d a g a i n w i t h t h e o n s e t o f a m a j o r g l a c i -a t i o n and Semiahmoo? p r o g l a c i a l ? s and was l a i d down a t P o r t Moody by sou t hwa r d - f 1 ow i ng m e l t w a t e r s t r e a m s ( F i g . 4 - 7 E ) p r o b -a b l y more t h a n 6 2 , 0 0 0 y e a r s [ f r o m an a d v a n c i n g g l a c i e r t o t h e n o r t h i n t h e C o a s t M o u n t a i n s ( F i g . 4-8Ft). P i e c e s o f i c e and p o s s i b l y t r e e p a r t s f l o a t e d i n t h e s t r e a m s , d r o p p i n g s t o n e s and s t o n e c l u s t e r s i n t o t h e s a n d . The s and was e r o d e d by i n c r e a s i n g m e l t w a t e r d i s c h a r g e s as t h e g l a c i e r a d v a n c e d f u r t h e r s o u t h w a r d . C o a r s e r o u t w a s h g r a v e l and s and w e r e d e p o s i t e d by t h e s e l a r g e r , more c o m p e t e n t s t r e a m s a t Mary H i l l and i n t h e C o q u i t l a m v a l l e y . E v e n t u a l l y t h e s o u t h w a r d - a d v a n c i n g Semiahmoo? g l a c i e r ( F i g s . 4 - 6 0 , 4 -8 F ) , o ve r r o d e t he Coq u i 11 am-Po r t Moody a r e a , c a r v i n g o u t new l a n d s c a p e s and r e s h a p i n g o l d one s w h i l e d e v e l o p i n g f a u l t s i n 79. Semiahmoo? p r o g l a c i a l ? s a nd s w i t h i t s w e i g h t a t P o r t Moody. A t l e a s t two a d v a n c e s and b r i e f r e t r e a t s o f t h i s i c e a r e r e p r e s e n t e d area Ay i n t h e C o q u i t l a m - P o r t M o o d y ^ l o d g e m e n t t i l l s s e p a r a t e d by g r a v e l and sand o u t w a s h . D u r i n g Semiahmoo? d e g l a c i a t i o n t h e sea e u s -t a t i c a l l y r o s e and c l o s e l y f o l l o w e d t h e i c e r e t r e a t ; Mary H i l l , and p r e s u m a b l y t h e w h o l e a r e a , was d r owned and t h e C o q u i t l a m v a l l e y p r o b a b l y became a f i o r d . G l a c i o m a r i n e s e d i m e n t s we re f o r m e d by d r i f t i n g i c e m e l t i n g and r a n d o m l y d r o p p i n g s t o n e s i n t o sea f l o o r mud ( F i g . ^1-6E) and we re d e p o s i t e d up t o 135 m a . s . l . The l a n d t h e n i s o s t a t i c a 1 1 y r o s e a b o v e t h e sea and a t Mary H i l l g l a c i o l a c u s t r i n e l a m i n a t e d s i l t s w i t h d r o p s t o n e s we re d e p o s i t e d i n a r a i s e d s ea f l o o r d e p r e s s i o n ( p o s s i b l y f o r m e d by s c o u r i n g a n d / o r p e r c u s s i o n b y d r i f t i n g i c e k e e l s ) by m e l t w a t e r f o r m i n g a pond o r l a k e i n i t . Wood ( Q L . - 1 9 M f r o m t h e l a m i n a t e d s i l t s was d a t e d as >62 ,000 r a d i o c a r b o n y r . B . P . . I t may r e p r e s e n t r e w o r k e d wood f r o m o l d e r n o n g l a c i a l s e d i m e n t s . An e r o s i o n a l i n t e r v a l f o l l o w e d Semiahmoo? d e g l a c i a t i o n and a l a n d s c a p e was f o r m e d on Semiahmoo? D r i f t . The t o p o g r a p h y o f t h e C o q u i t l a m - P o r t Moody a r e a has r e m a i n e d b a s i c a l l y t h e same s i n c e Semiahmoo? t i m e and has o n l y been l o c a l l y m o d i f i e d by i c e and w a t e r a c t i o n . The s t r a t i g r a p h i c r e c o r d p r i o r t o Semiahmoo? t i m e i s t o o s p a r c e i n t h e a r e a t o comment on t h e t o p o g r a p h y b e f o r e t h e n . The u p l a n d s a t Mary H i l l , P o r t Moody, Ma i11 a r d v i 1 1 e , and H a r b o u r V i l l a g e e x i s t e d i n Semiahmoo? t i m e , a l t h o u g h i n a d i f f e r e n t s h a p e . The l o w l a n d s b e t w e e n P o r t Moody and l o c o , and b e t w e e n E s s o n d a l e and Mary H i l l a l s o e x i s t e d t h e n , a l s o i n a d i f f e r e n t f o r m . The n e x t s e d i m e n t t o be d e p o s i t e d i n t h e a r e a was t h e s t o n y o r g a n i c c o l l u v i u m e x p o s e d a t Mary H i l l and t e n t a t i v e l y g r o u p e d 80. w i t h t h e C o w i c h a n Head F o r m a t i o n . I t f o r m e d on a s l o p e a t t h e edge o f a d e p r e s s i o n a t Mary H i l l a b o u t 4 0 , 0 0 0 y e a r s a g o , p r o b -a b l y d u r i n g a n o n g l a c i a l i n t e r v a l , by mass w a s t i n g p r o c e s s e s a c t i n g on and m i x i n g o r g a n i c d e p o s i t s ( c o n t a i n i n g s p r u c e and w e s t e r n h e m l o c k t r e e s ) and g l a c i a l s e d i m e n t s . A r m s t r o n g ( i n p r e p . ) has e v i d e n c e o f a n o n g l a c i a l i n t e r v a l e x i s t i n g i n N o r t h V a n c o u v e r (20 km w e s t o f t h e C o q u i t l a m - P o r t Moody a r e a ) a t 3 6 , 2 0 0 r a d i o c a r b o n y r . B .P . (GSC 93 r e r u n ) and 32 ,200 r a d i o -c a r b o n y r . B .P . ( IGSC 2 1 4 ) , and i n V a n c o u v e r a t 32 ,580 r a d i o -c a r b o n y r . B .P . (GSC 2 2 1 ) . From e a s t D e l t a (10 km s o u t h w e s t o f t h e C o q u i t l a m - P o r t Moody a r e a ) A r m s t r o n g ( p e r s . comm.) had wood f r o m a b u r i e d f o r e s t d a t e d as 5 8 , 8 0 0 ^ 9 0 0 (QL - 195 , S t u i v e r , U. o f Wash. ) and b e l i e v e s t h a t t h e age o f t h e C o w i c h a n Head F o r m a t i o n may r a n g e f r o m 2 5 , 0 0 0 - 6 0 , 0 0 0 r a d i o c a r b o n y r . B .P . By a b o u t 30 ,000 y e a r s ago bog and swamp d e p o s i t s o f t h e Cow-i c h a n Head F o r m a t i o n had f o r m e d a t Mary H i l l d u r i n g t h e O l y m p i a N o n g l a c i a l I n t e r v a l . S p r u c e t r e e s we re g r o w i n g i n t h e p e a t and i n t e r b e d d e d sand l a y e r s , w h i c h a b u t t e d a g a i n s t a s l o p e d e v e -l o p e d on t h e o r g a n i c c o l l u v i u m . From a b o u t 2 6 , 0 0 0 t o 2 5 , 5 0 0 y e a r s ago f l u v i a l s i l t , s a n d , g r a v e l , and swamp d e p o s i t s ( i n w h i c h s p r u c e and w e s t e r n f i r t r e e s g r ew) o f t h e C o w i c h a n Head F o r m a t i o n we re l a i d down o v e r t h e bog d e p o s i t s and a l s o a b u t t e d a g a i n s t t h e s l o p e on t h e o r g a n i c c o l l u v i u m . T h e s e f l u v i a l s e d i -ment s we re d e p o s i t e d by s t r e a m s f l o w i n g s o u t h w a r d ( F i g . ^f-7D) o f f t h e C o a s t M o u n t a i n s ( F i g . 4-8 E) . At Mary H i l l a sand u n i t , t e x -t u r a l l y and s t r u c t u r a l l y s i m i l a r t o Quad ra S a n d , o v e r l i e s swamp d e p o s i t s o f t h e C o w i c h a n Head F o r m a t i o n and u n d e r l i e s C o q u i t l a m 81. D r i f t ; t h u s i t has been mapped w i t h t h e C o w i c h a n Head F o r m a t i o n . H o w e v e r , t h i s l o w e r s and may i n f a c t be Quad ra Sand d e p o s i t e d e a r l y i n t h e F r a s e r G l a c i a t i o n , p r i o r t o t h e d e p o s i t i o n o f C o q u i t l a m D r i f t . A l a n d s c a p e was f o r m e d on t h e C o w i c h a n Head F o r m a t i o n . The c l i m a t e c o o l e d a g a i n w i t h t h e o n s e t o f t h e F r a s e r G l a c i a t i o n , l e s s t h a n 2 6 , 0 0 0 y e a r s a g o . P r o b a b l y p r o g l a c i a l Quad ra Sand was t h e e a r l i e s t s e d i m e n t t o be d e p o s i t e d i n t h e a d v a n c i n g V a s h o n ? i c e t o t h e n o r t h i n t h e C o a s t M o u n t a i n s . I t a p p e a r s t h a t a t Mary H i l l e a r l y i n t h e F r a s e r G l a c i a t i o n Quadra Sand d e p o s i t i o n was i n t e r r u p t e d by t h e w e s t w a r d a d v a n c e o f a l o c a l p i e d m o n t i c e l o b e , p o s s i b l y s u r g i n g , f r o m t h e C a s c a d e M o u n t a i n s . T h i s s t a d i a l e v e n t i s r e p r e s e n t e d by C o q u i t l a m D r i f t , w h i c h i s t h o u g h t t o be m a i n l y g l a c i o m a r i n e s e d i m e n t s ( c o n t a i n s f o s s i l m a r i n e s h e l l f r a g m e n t s ) , bu t may i n p a r t be t i l l . The p e b b l e p r o v e n a n c e f o r t h i s u n i t has a s t r o n g e a s t e r n componen t ( F i g . ^ftD) and p e b b l e f a b r i c s s u g g e s t i c e movement was f r o m t h e e a s t and n o r t h ( F i g . ^ - 6 C ) . T h i s m i x t u r e o f t i l l -l i k e and g l a c i o m a r i n e s e d i m e n t s was p r o b a b l y c a u s e d by w e s t w a r d -a d v a n c i n g C o q u i t l a m i c e o v e r r i d i n g and d i s t u r b i n g C o q u i t l a m g l a c i o m a r i n e s e d i m e n t s . The sand b e l o w C o q u i t l a m D r i f t p r o b a b l y d e v e l o p e d f a u l t s u n d e r t h e w e i g h t o f o v e r r i d i n g C o q u i t l a m i c e . The C o q u i t l a m i c e l o b e a p p e a r s t o have b l o c k e d t h e mouth o f t h e C o q u i t l a m v a l l e y w h i l e p r o g l a c i a l Quad ra Sand was d e p o s i -t e d ( b e h i n d an i c e dam) up t o 2 5 0 m a . s . l . i n t h e v a l l e y by 2 1 , 6 0 0 y e a r s B .P . W i t h o u t t h i s i c e dam Quad ra Sand may have f i l l e d t h e w h o l e F r a s e r L o w l a n d and S t r a i t o f G e o r g i a t o t h a t e l e v a t i o n . I f t h e l a t t e r was t h e c a s e , most o f t h e Quad ra Sand 82. has been e r o d e d and r e d e p o s i t e d e l s e w h e r e ; h o w e v e r , e v i d e n c e f o r t h e l a t t e r h y p o t h e s i s i s l a c k i n g . The w e s t e r n l i m i t o f a d v a n c e f o r t h e C o q u i t l a m i c e i s u n known ; howeve r H a l s t e a d ( 1968 ) and F u l t o n and H a l s t e a d (1972 ) d e s c r i b e d a d r i f t u n i t on t h e S a a n i c h P e n i n s u l a , V a n c o u v e r I s l a n d , w h i c h t h e y c o r r e l a t e w i t h Evans C r e e k D r i f t f o u n d i n n o r t h w e s t e r n W a s h i n g t o n . T h e i r d r i f t u n i t may c o r r e l a t e w i t h C o q u i t l a m D r i f t , w h i c h may a l s o c o r r e l a t e w i t h Evans C r e e k D r i f t . A l a n d s c a p e was f o r m e d on C o q u i t l a m D r i f t . C o q u i t l a m i c e must have w i t h d r a w n f r o m Mary H i l l by 1 8 , 6 00 y e a r s B . P . , when t h e Va shon i c e s h e e t was s t i l l ( ? ) a d v a n c i n g f r o m t h e C o a s t M o u n t a i n s , t o w a r d s t h e C o q u i t l a m - P o r t Moody a r e a , and t h e c l i m a t e had warmed enough t o a l l o w t h e f o r m a t i o n o f a t h i n p e a t bed c o n t a i n i n g s p r u c e t r e e s a t Mary H i l l . S t a g n a n t i c e may have c o n t i n u e d t o b l o c k p a r t o f t h e C o q u i t l a m v a l l e y , d i v e r t i n g s t r e a m f l o w a r o u n d i c e - f r e e Mary H i l l d u r i n g t h i s t i m e . E v i d e n c e t o s u p p o r t t h i s h y p o t h e s i s may have been e r a s e d l a t e r d u r i n g t h e Va shon S t a d e . D u r i n g and a f t e r r e t r e a t o f t h e C o q u i t -lam i c e b l o c k s o u t h w a r d - f 1 o w i n g m e l t w a t e r s t r e a m s ( F i g . 4-7C) e r o d e d much o f t h e Quad ra Sand i n t h e l o w e r C o q u i t l a m v a l l e y and r e d e p o s i t e d i t , w i t h new Quadra S a n d , i n t h e F r a s e r L o w l a n d . A t Mary H i l l and p r o b a b l y i n t h e Ma i11 a r d v i 1 1 e - H a r b o u r V i l l a g e u p l a n d , b o t h i m m e d i a t e l y s o u t h o f C o q u i t l a m v a l l e y , Quad ra Sand was d e p o s i t e d up t o 50 m t h i c k . The G u i l d f o r d a r e a , s o u t h o f Mary H i l l a c r o s s t h e F r a s e r R i v e r , c o n t a i n s Quad ra Sand a t l e a s t 60 m t h i c k . S t r e a m s f l o w e d i n s h a l l o w , w i d e c h a n n e l s and s t r e a m d i s c h a r g e and c o m p e t e n c e was low d u r i n g i n i t i a l Quad ra Sand ( f i n e t o medium) d e p o s i t i o n , when C o q u i t l a m i c e was r e t r e a t i n g , 83. and s t a g n a n t i c e may have b l o c k e d most o f t he mouth o f the C o q u i t l a m v a l l e y . As t he s t a g n a n t i c e b l o c k d i s i n t e g r a t e d , a l l o w i n g more w a t e r to p a s s , and as the Va shon i c e a d v a n c e d c l o s e r to the a r e a , s t r e a m d i s c h a r g e and c o m p e t e n c e i n c r e a s e d and w a t e r f l o w e d s o u t h w a r d in d e e p e r , n a r r o w e r c h a n n e l s , d e p o s i t i n g more and more C o a s t M o u n t a i n s - d e r i v e d g r a v e l ( F i g . 4-8C) w i t h the s a n d . Water a c t i o n c r e a t e d a new l a n d s c a p e on Quad ra Sand . E v e n t u a l l y Vashon i c e a d v a n c e d s o u t h w a r d o f f t h e C o a s t M o u n t a i n s and o n t o t he F r a s e r L o w l a n d . S o u t h w a r d - f 1 o w i n g , h i g h -d i s c h a r g e ou twash s t r e a m s ( F i g . 4-7 B) d e p o s i t e d C o a s t M o u n t a i n s -d e r i v e d ( F i g . 4-8B) Va shon c o a r s e g r a v e l ou twash as f o r e s e t beds i n t o t he sea as t he l a n d was i s o s t a t i c a 1 1 y d e p r e s s e d . D u r i n g t h i s t ime f l o w t i l l s and i c e - c o n t a c t d e p o s i t s were d e p o s i t e d in the l ower C o q u i t l a m v a l l e y . C o a r s e ou twash and i c e - c o n t a c t d e p o s i t s were not o b s e r v e d a t t h e P o r t Moody d i s p o s a l s i t e , p e r -haps b e c a u s e t h e y were e r a s e d by Vashon i c e or p e r h a p s b e c a u s e P o r t Moody was too f a r to t he west o f t he C o q u i t l a m R i v e r and away f r om the main s t r e a m f l o w down the C o q u i t l a m v a l l e y . The l a t t e r i s u n l i k e l y as Va shon i c e p a s s e d o v e r t he s i t e and came down I n d i a n Arm, to the n o r t h o f P o r t Moody, and would have d e p o s i t e d ou twash a t t he s i t e . Vashon i c e e v e n t u a l l y p a s s e d o v e r t he a r e a , m o s t l y r e w o r k i n and r e d e p o s i t i n g i t s own ou twash d e p o s i t s , and d e p o s i t e d l o d g e -ment and f l o w t i l l s . S t o n e s in the Vashon t i l l s a r e s u b r o u n d e d where t i l l s o v e r l i e P l e i s t o c e n e s e d i m e n t s in t he a r e a . T h i s i n d i c a t e s t h a t Vashon i c e r e w o r k e d o l d e r s e d i m e n t s when i t 84. o v e r r o d e t h e l a n d w h e r e b e d r o c k was b u r i e d d e e p l y b e l o w t h e s u r f a c e . Semiahmoo? t i l l s c o n t a i n many r o u n d e d s t o n e s and Semiahmoo? i c e p r o b a b l y a c t e d i n a s i m i l a r m a n n e r . A t l e a s t t h r e e V a s h o n t i l l s s e p a r a t e d by o u t w a s h g r a v e l s a r e f o u n d i n t h e a r e a and r e p r e s e n t l o c a l i c e a d v a n c e s t h a t o c c u r r e d d u r i n g t h e V a s h o n S t a d e . P e b b l e f a b r i c and p r o v e n a n c e s t u d i e s ( F i g s . *{-GB, ^r8B) i n d i c a t e s o u t h w a r d i c e movement f o r a l l t h r e e a d v a n c e s . Each i c e a d v a n c e e r o d e d o l d e r s e d i m e n t s and d e p o s i t e d t i l l w h i c h t r u n c a t e d t h e one s l a i d down b e f o r e i t . L a m i n a t e d s t o n y s i l t and f i n e s and l e n s e s i n t h e t i l l s w e r e f o r m e d by f i n e s e d i m e n t s and i c e - r a f t e d d r o p s t o n e s b e i n g d e p o s i t e d i n s m a l l m e l t w a t e r ponds o c c u p y i n g h o l l o w s on t h e t i l l s u r f a c e . A m a j o r l a n d s c a p e was d e v e l o p e d on V a s h o n D r i f t . By 13 ,000 y e a r s B .P . t h e c l i m a t e was w a r m i n g and F r a s e r d e g l a c i a t i o n had begun i n t h e C o q u i t l a m - P o r t Moody a r e a , a l t h o u g h t h e F o r t L a n g l e y and Sumas S t a d e s had s t a r t e d i n t h e e a s t e r n F r a s e r L o w l a n d ( A r m s t r o n g , i n p r e s s ) . The s ea c l o s e l y f o l l o w e d t h e r e t r e a t i n g Va shon i c e i n t o t h e C o q u i t l a m v a l l e y w h e r e C a p i -l a n o f o s s i 1 i f e r o u s m a r i n e and g l a c i o m a r i n e s e d i m e n t s w e r e d e p o -s i t e d t o a t l e a s t 70 m a . s . l . , 12,000 y e a r s a g o . D u r i n g t h i s t i m e t h e C o q u i t l a m v a l l e y was a f i o r d ; Ma ry H i l l , P o r t Moody , and t h e Ma i11 a r d v i 1 1 e - H a r b o u r V i l l a g e u p l a n d we re d r owned by t h e s e a ; and f l o a t i n g i c e r a n d o m l y d r o p p e d s t o n e s i n t o s e a -f l o o r muds ( F i g / T 6 A ) . W i t h f u r t h e r r e t r e a t o f V a s h o n i c e i n t o t h e C o a s t M o u n t a i n s t h e l a n d s t a r t e d t o i s o s t a t i c a 1 1 y r i s e f a s t e r t h a n t h e e u s t a t i c a l l y r i s i n g sea l e v e l . A C a p i l a n o c o m p o s i t e m a r i n e d e l t a was f o r m e d up t o 140 m a . s . l . a t t h e mouth o f t h e C o q u i t l a m v a l l e y . b y s o u t h w a r d - f 1 o w i n g m e l t w a t e r s t r e a m s d e b o u c h i n g f r o m t h e r e t r e a t i n g g l a c i e r t o t h e n o r t h ( F i g s . 4-7A, 4-8A) . As t h e l a n d r o s e a b o v e t h e s e a , s t o r m waves and s p r a y pounded a g a i n s t t h e u p l a n d s l o p e s i n t h e a r e a , r e -w o r k i n g C a p i l a n o g l a c i o m a r i n e s e d i m e n t s and V a s h o n D r i f t . S u p r a l i t t o r a l l a g g r a v e l s and l i t t o r a l s a n d s w i nnowed f r o m t h e m , b o t h c o n t a i n i n g m a r i n e s h e l l c a s t s , we re f o r m e d and d e p o s i t e d up t o 175 m a . s . l . by t h i s wave a c t i o n . A t t h e same t i m e t e r r a c e s w e r e c u t i n t o t h e c o m p o s i t e d e l t a a t t h e mouth o f t h e C o q u i t l a m v a l l e y . D u r i n g t h e d e p o s i t i o n o f t h e r a i s e d d e l t a s and s u p r a l i t t o r a l l a g g r a v e l t h e C o q u i t l a m -P o r t Moody a r e a was e n t e r i n g p o s t - g l a c i a l t i m e , w h i l e e a s t e r n F r a s e r L o w l a n d was s t i l l i n t h e Sumas S t a d e ( A r m s t r o n g , i n p r e s s ) , a b o u t 1 1 , 500 y e a r s a g o . D u r i n g p o s t - g l a c i a l t i m e t h e a n c e s t r a l C o q u i t l a m R i v e r i n c i s e d t h e C o q u i t l a m v a l l e y s e d i m e n t f i l l and d e p o s i t e d s and and g r a v e l , l a r g e l y r e w o r k e d f r o m o l d e r s e d i m e n t s e x p o s e d a l o n g t h e r i v e r b a n k s , a l o n g i t s l o w e r c o u r s e f r o m C o q u i t l a m Lake t o t h e F r a s e r R i v e r . I t a l s o b u i l t a f l o o d p l a i n e x t e n d i n g f r o m t h e l o w e s t s l o p e s o f B u r k e M t . t o i t s m o u t h . Ove r t h e C o q u i t -lam R i v e r f l o o d p l a i n b e t w e e n E s s o n d a l e and Mary H i l l , and b e l o w Ma i11 a r d v i 1 1 e , t h e F r a s e r R i v e r has d e p o s i t e d f l o o d p l a i n and e s t u a r i n e s and and s i l t . In p l a c e s p e a t bog and swamp d e p o s i t s have a l s o f o r m e d on t h e F r a s e r f l o o d p l a i n . M o u n t a i n s t r e a m s , l o w l a n d s t r e a m s , s l i d e s , mass w a s t i n g , and human a c t i -v i t y have a l s o p l a y e d r o l e s i n t h e d e p o s i t i o n and e r o s i o n o f u n c o n s o l i d a t e d s e d i m e n t s s i n c e t h e r e t r e a t o f t h e l a s t i c e f r o m t h e C o q u i1 1 a m - P o r t Moody a r e a . 86. CHAPTER SEVEN: ENGINEERING AND ENVIRONMENTAL GEOLOGY E n v i r o n m e n t a l p r o b l e m s r e l a t e d to s u r f i c i a l g e o l o g y , and s o u r c e s o f g r a n u l a r a g g r e g a t e have been d i s c u s s e d f o r the F r a s e r Lowland by A r m s t r o n g (1953, 1957, 1961) and Learning (1968). T h i s c h a p t e r i s a summary o f t h e s e p a p e r s f o r t he C o q u i t l a m -P o r t Moody a r e a , i n c l u d i n g m i n o r i n p u t f rom t h i s s t u d y . I n f o r m -a t i o n on t h e t y p e s and d i s t r i b u t i o n o f g e o l o g i c a l m a t e r i a l s a i d the e n g i n e e r , p l a n n e r , and c o n t r a c t o r in s o l v i n g p r o b l e m s p e r -t a i n i n g to c o n s t r u c t i o n m a t e r i a l s , f o u n d a t i o n m a t e r i a l s and d r a i n a g e , sewage d i s p o s a l , f l o o d c o n t r o l , s l i d e s , and w a s h o u t s . C o n s t r u c t i o n M a t e r i a l s G r a v e l and sand a r e the o n l y m a t e r i a l s mined f rom Q u a t e r n a r y s e d i m e n t s in t he Coqu i11 a m - P o r t Moody a r e a f o r c o n s t r u c t i o n p u r p o s e s , and g r a v e l and sand p r o d u c t i o n i s an i m p o r t a n t i n d u s t r y in the a r e a . S o u r c e s and t y p e s o f sand and g r a v e l d e p o s i t s have been d e s c r i b e d by A r m s t r o n g (1953, 1957) and Learning (19 6 8, pp. 40-49) has d e s c r i b e d in d e t a i l t he sand and g r a v e l o p e r a t i o n s in the C o q u i t l a m - P o r t Moody a r e a d u r i n g the 1960 ' s . G r a v e l and sand d e p o s i t s in t he a r e a may be c l a s s i f i e d i n t o f o u r t y p e s : 1. ou twash g r a v e l and sand ( F i g s . 22, 23, 36, 43, 44) 2. r a i s e d d e l t a and a l l u v i a l f l o o d p l a i n g r a v e l and sand ( F i g s . 17, 31, 41, 43), 3. s u p r a l i t t o r a l g r a v e l and sand ( F i g s . 15, 16), and 4. p r e s e n t - d a y r i v e r g r a v e l . D e p o s i t s o f t h e f i r s t t y p e a r e t h e most e x t e n s i v e and e c o n -o m i c , e s p e c i a l l y Vashon ou twash d e p o s i t s , w h i c h were the l a s t d e p o s i t s o f t h i s t y p e to be l a i d down. The o t h e r ou twash u n i t s 8 7 . a r e : Quad ra S a n d , Sem iahmoo ? , and W e s t l y n n ? . T h e s e s e d i m e n t s w e r e l a i d down by m e l t w a t e r s t r e a m s d e b o u c h i n g f r o m a d v a n c i n g and r e t r e a t i n g g l a c i e r s . F i g . 4-9 i l l u s t r a t e s g r a i n - s i z e c u r v e s f o r t h r e e o f t h e f o u r t y p e s o f g r a v e l d e p o s i t s e x p o s e d i n t h e s t u d y a r e a . S a m p l e s o f modern r i v e r g r a v e l s we re no t a n a l y z e d and Quad ra Sand ( F i g s . 2k, 2 5 , 2 7 , 2 8 ) c o n t a i n s v e r y m i n o r g r a v e l . A l l t h r e e t y p e s o f g r a v e l d e p o s i t s c o n t a i n g r a i n s r a n g i n g i n s i z e f r o m s i l t t o b o u l d e r s ; h o w e v e r , t h e a b u n d a n c e o f t h e s e s i z e s i s l e s s t h a n 1%. Ou twash g r a v e l s ( F i g . ^9A) g e n e r a l l y c o n t a i n 7 5 % (by w e i g h t ) g r a v e l - s i z e d m a t e r i a l ; t h e r e m a i n i n g 25% i s l a r g e l y composed o f s a n d . Mos t o f t h e g r a v e l f r a c t i o n i s p e b b l e - s i z e d {k t o 3 2 mm) s t o n e s . R a i s e d d e l t a i c and a l l u v i a l f l o o d p l a i n d e p o s i t s ( F i g . •4-98) g e n e r a l l y c o n t a i n 6 5 % (by w e i g h t ) g r a v e l - s i z e d m a t e r i a l and 35% s a n d ; most o f t h e g r a v e l f r a c t i o n i s made o f s m a l l e r p e b b l e s (k t o 2 0 mm) t h a n t h e o u t w a s h . T h e s e g r a v e l s a r e s l i g h t l y b e t t e r s o r t e d t h a n o u t w a s h g r a v e l s as t h e y c o n t a i n l i t t l e o r no mud f r a c t i o n and v e r y few b o u l d e r s . R a i s e d d e l t a d e p o s i t s ( F i g . 1 7 ) a r e a c t u a l l y r e c e s s i o n a l o u t w a s h d e p o s i t e d a t t h e end o f t h e l a s t g l a c i a t i o n . H o w e v e r , t h e y we re l a i d down by s t r e a m s d e r i v e d f r o m r e t r e a t i n g i c e t h a t was f a r t h e r f r o m t h e a r e a t h a n g l a c i e r s a s s o -c i a t e d w i t h t h e o u t w a s h g r a v e l s . L o n g e r t r a n s p o r t d i s t a n c e s and g r e a t e r t r a v e l t i m e r e s u l t e d i n b e t t e r s o r t i n g o f t h e r a i s e d d e l t a g r a v e l s . R a i s e d d e l t a g r a v e l s a r e a l s o s l i g h t l y more r o u n d e d t h a n t h e o u t w a s h . N o n g l a c i a l a l l u v i a l f l o o d p l a i n g r a v e l s ( F i g s . 3 1 , k\, k3) ( C o w i c h a n H e a d , H i g h b u r y ? ) we re n o t , o f c o u r s e , d e p o s i t e d by g l a c i e r - d e r i v e d s t r e a m s b u t w e r e d e p o s i t e d as c h a n -n e l and f l o o d p l a i n d e p o s i t s and a r e b e t t e r s o r t e d t h a n o u t w a s h . u X O UJ > 256 128 64 32 16 8 99. 1 «H 75H 50-25-5H 4 2 ' 0.5 0.25 ( phi units) GRAIN SIZE (millimetres) 1 0 1 2 3 4 5 c 1 1 1 // / ' / \ / / / I' I // 1 F i g . 49: GRAIN SIZE DISTRIBUTION OF PLEISTOCENE GRAVEL DEPOSITS: COQUITLAM-PORT MOODY AREA, BRITISH COLUMBIA. A. GLACIAL OUTWASH B. RAISED DELTA AND ALLUVIAL FLOODPLAIN C. SUPRALITTORAL D. AREAS OF GRAIN SIZE DISTRIBUTION. co 00 89. S u p r a l i t t o r a l g r a v e l s ( F i g . 4-9C) g e n e r a l l y c o n t a i n 80% g r a v e l -s i z e d m a t e r i a l , commonly h e a v i l y s t a i n e d by i r o n o x i d e s , bu t t h e r e m a i n i n g 20% i s m o s t l y composed o f f i n e sand and mud. In t h i s t y p e t h e g r a v e l f r a c t i o n i s m o s t l y p e b b l e - s i z e d {k t o 32 mm) s t o n e s . The se g r a v e l d e p o s i t s a r e b i m o d a l , c o n t a i n i n g a l a r g e g r a v e l f r a c t i o n s u r r o u n d e d by a l e s s e r mud m a t r i x . T h i s b i m o d r a l i t y r e s u l t e d f r o m sea waves and s p r a y r e w o r k i n g Va shon t i l l and C a p i l a n o g l a c i o m a r i n e s e d i m e n t s and p a r t l y w i n n o w i n g o u t t h e f i n e s t o f o r m t h e s u p r a l i t t o r a l l a g g r a v e l . In F i g . 4-9D f i e l d l i m i t s f o r t h e t h r e e P l e i s t o c e n e g r a v e l t y p e s a r e s u p e r i m p o s e d f o r d i r e c t c o m p a r i s o n . S u p r a l i t t o r a l g r a v e l a n a l y s e s we re d i f f i -c u l t t o p e r f o r m and o n l y t h r e e we re d o n e ; t h u s f i e l d l i m i t s have been e s t i m a t e d f o r t h i s . t y p e . L i m i t e d e x p o s u r e s o f p r e - V a s h o n o u t w a s h d e p o s i t s o c c u r i n t h e w e s t bank o f t h e l o w e r C o q u i t l a m R i v e r v a l l e y and some c o m p a n i e s o p e r a t i n g t h e r e a r e m i n i n g t h e m . E l s e w h e r e i n t h e s t u d y a r e a p r e - V a s h o n o u t w a s h i s o n l y e x p o s e d a t Mary H i l l and P o r t Moody. In t h e C o q u i t l a m R i v e r v a l l e y Semiahmoo? o u t w a s h ]k m t h i c k i s e x p o s e d a t p i t F ( F i g s . 1 , 7) and W e s t l y n n ? o u t -wash a t p i t s E, F, and G. Semiahmoo? and Va shon o u t w a s h g r a v e l s a r e o v e r l a i n by t i l l a n d / o r g l a c i o m a r i n e s e d i m e n t s , w h i c h must be removed w i t h o r p r i o r t o e x t r a c t i o n o f o u t w a s h g r a v e l . No t i l l was f o u n d t o d i r e c t l y o v e r l i e W e s t l y n n ? o u t w a s h . V a s h o n .and Semiahmoo? o u t w a s h v a r y i n t h i c k n e s s and t h e i r c o n t a c t s w i t h a d j a c e n t s e d i m e n t u n i t s a r e t h r e e - d i m e n s i o n a l u n d u l a t i n g s u r f a c e s T h e s e s u r f a c e s a r e b u r i e d l a n d s c a p e s f o r m e d by w a t e r and i c e a c t i o n . B e c a u s e o f them e s t i m a t i o n o f g r a v e l and sand r e s e r v e s 90. and o f t h e l a t e r a l and v e r t i c a l c o n t i n u i t y o f p i t r un m a t e r i a l i s e x t r e m e l y d i f f i c u l t . W e s t l y n n ? o u t w a s h , h o w e v e r , a p p e a r s t o have a p l a n a r u p p e r c o n t a c t w i t h H i g h b u r y ? s e d i m e n t s i n t h e l o w e r C o q u i t l a m R i v e r v a l l e y ; t h e l o w e r c o n t a c t was no t e x p o s e d . R a i s e d d e l t a and a l l u v i a l f l o o d p l a i n g r a v e l d e p o s i t s i n -c l u d e C a p i l a n o r a i s e d d e l t a s , C o w i c h a n Head F o r m a t i o n f l u v i a l s e d i m e n t s and H i g h b u r y ? f l u v i a l i n t e r b e d d e d sand and g r a v e l . As s t a t e d i n C h a p t e r S i x , C a p i l a n o s e d i m e n t s w e r e d e p o s i t e d a t t h e end o f t h e l a s t g l a c i a t i o n as a c o m p o s i t e m a r i n e d e l t a up t o 140 m a . s . l . a t t h e mouth o f t h e a n c e s t r a l C o q u i t l a m R i v e r . C o w i c h a n Head g r a v e l was d e p o s i t e d by n o n g l a c i a l s t r e a m s as f l o o d p l a i n s e d i m e n t s d u r i n g t h e O l y m p i a N o n g l a c i a l I n t e r v a l . H i g h b u r y ? s e d i m e n t s w e r e d e p o s i t e d as c h a n n e l and f l o o d p l a i n d e p o s i t s d u r i n g a p r e - O l y m p i a n o n g l a c i a l i n t e r v a l . C u r v e s i n F i g . 4-9B p l o t t e d f r o m a n a l y s e s o f H i g h b u r y ? g r a v e l a r e ba sed o n l y on t h e g r a v e l beds i n t h i s u n i t . T h e r e i s more sand t h a n g r a v e l i n H i g h b u r y ? s e d i m e n t s ( F i g s . 4 1 , 4 2 , 4 3 ) . In p l a c e s C a p i l a n o d e l t a i c g r a v e l i s o v e r l a i n by a m a n t l e o f s u p r a l i t t o r a l l a g g r a v e l up t o 1 m t h i c k . C o w i c h a n Head g r a v e l i s o v e r l a i n by C o q u i t l a m s t o n y c l a y e y s i l t w h i c h must be removed w i t h o r p r i o r t o g r a v e l e x t r a c t i o n . H i g h b u r y ? sand and g r a v e l l i e s b e t w e e n W e s t l y n n ? and Semiahmoo? o u t w a s h i n t h e l o w e r C o q u i t l a m R i v e r v a l l e y and i s e a s i l y m i n e d . C a p i l a n o d e l t a i c g r a v e l i s f a n - s h a p e d and p i n c h e s o u t n o r t h w a r d a g a i n s t a b u r i e d l a n d s c a p e f o r m e d on Va shon D r i f t i n t h e l o w e r C o q u i t l a m v a l l e y . J>edded H i g h b u r y ? S e d i m e n t s a p p e a r h o r i z o n t a 1 1 y ^ a n d c o n t i n u e a t u n i f o r m t h i c k n e s s f o r 2 km a l o n g P i p e l i n e R o a d , on t h e w e s t s i d e o f C o q u i t l a m R i v e r , f r o m p i t G a l m o s t t o p i t E ( F i g s . 1, 7)> w h e r e 91. t h e y a r e t r u n c a t e d by V a s h o n D r i f t . C a p i l a n o s u p r a l i t t o r a l l a g g r a v e l was f o r m e d by t h e r e w o r k -i n g o f Va shon t i l l and C a p i l a n o g l a c i o m a r i n e s e d i m e n t s by m a r i n e a c t i o n , d i s c u s s e d p r e v i o u s l y , and o c c u r s as a t h i n m a n t l e c o v e r -i n g t h e s e d i a m i c t o n s . I t u s u a l l y t o o t h i n and t o o d i r t y ( com-mon l y c o n t a i n s 20% f i n e s and and mud m a t r i x , i r o n s t a i n e d ) t o be e c o n o m i c a l l y i m p o r t a n t ; h o w e v e r , w h e r e m a r i n e a c t i o n c u t t h r o u g h t h e u n d e r l y i n g d i a m i c t o n i t may d i r e c t l y o v e r l i e Va shon o u t w a s h and t o g e t h e r t h e s e d e p o s i t s c an be m i n e a b l e . P r e s e n t - d a y s t r e a m g r a v e l m a i n l y o c c u r s as c h a n n e l b a r s and bed m a t e r i a l o f t h e C o q u i t l a m R i v e r . Mos t o f t h i s g r a v e l i s e r o d e d f r o m t h e r i v e r b a n k s , w h i c h a r e l a r g e l y composed o f P l e i s -t o c e n e g l a c i a l s e d i m e n t s , and t r a n s p o r t e d by t o r r e n t i a l w i n t e r r u n o f f s . Mos t o f t h e s and and f i n e r m a t e r i a l s a r e w i nnowed o u t and a l a g g r a v e l i s l e f t , m a i n l y c o n s i s t i n g o f w e l l s o r t e d , s u b -r o u n d e d g r a n i t i c c o b b l e s and b o u l d e r s . S m a l l e r m o u n t a i n s t r e a m s a s s o c i a t e d w i t h mass w a s t i n g p r o c e s s e s p r o d u c e a r a n g e o f g r a v e l s f r o m w e l l s o r t e d g r a v e l s t r e a m bed s t o d i r t y a l l u v i a l and c o l l u -v i a l s l o p e w a s h g r a v e l s i n s t r e a m bank s and on h i l l s i d e s . In summary , r a i s e d b e a c h l a g g r a v e l s a r e w i d e s p r e a d bu t t o o t h i n and d i r t y t o be e c o n o m i c a l . P r e s e n t - d a y r i v e r g r a v e l i s an i m p o r t a n t s o u r c e , b u t l i m i t e d i n e x t e n t ; h o w e v e r , i t i s c o n s t a n t l b e i n g r e p l e n i s h e d by t o r r e n t i a l w i n t e r r u n o f f s . R a i s e d d e l t a and a l l u v i a l f l o o d p l a i n d e p o s i t s f o r m an i m p o r t a n t s o u r c e and a r e t h e b e s t s o r t e d o f t h e P l e i s t o c e n e g r a v e l s bu t t h e y a r e a l s o l i m i t e d i n e x t e n t . They a r e a l s o common ly m i n e d w i t h u n d e r l y i n g o u t w a s h . The most e x t e n s i v e and e c o n o m i c a l l y i m p o r t a n t a r e t h e 92. o u t w a s h d e p o s i t s . V a shon o u t w a s h i s t h e most a c c e s s i b l e , b e i n g u s u a l l y n e a r e r t o t h e l a n d s u r f a c e t h a n o l d e r o u t w a s h d e p o s i t s ; h o w e v e r , i n t h e w e s t bank o f t h e l o w e r C o q u i t l a m R i v e r v a l l e y t h i c k s e c t i o n s o f o l d e r o u t w a s h have been e x p o s e d by g r a v e l o p e r a t o r s . B u r i e d i n Mary H i l l ( s e e F i g s . \k and 3 f o r d e p t h s ) and p r o b a b l y deep b e n e a t h t h e u p l a n d s a b o v e P o r t Moody and Ma i 1 -l a r d v i l l e l a r g e p r e - V a s h o n o u t w a s h , and f l u v i a l g r a v e l and sand r e s e r v e s a l s o e x i s t ; h o w e v e r , t h e i r l a t e r a l and v e r t i c a l e x t e n t s w i l l be d i f f i c u l t t o d e t e r m i n e by d r i 1 1 i n g me thod s b e c a u s e o f t h e i r r e g u l a r , t h r e e - d i m e n s i o n a l b u r i e d l a n d s c a p e s b o u n d i n g t h e s e u n i t s . M u n i c i p a l z o n i n g r e g u l a t i o n s p r e s e n t t h e l a r g e s t p r o b l e m t o g r a v e l and sand o p e r a t o r s i n t h e C o q u i t l a m - P o r t Moody a r e a . The g r a v e l and s and i n d u s t r y i s t h e m a j o r m i n i n g i n d u s t r y i n t h e F r a s e r L o w l a n d . B e f o r e t h e c l o s u r e o f t h e Mary H i l l o p e r a t i o n i n 1 975 , t h e a n n u a l p i t - h e a d p r o d u c t i o n p r o b a b l y e x c e e d e d 5 m i l l i o n c u b i c m e t e r s w i t h a p r e s e n t - d a y v a l u e o f a t l e a s t 6 m i l l i o n d o l l a r s a t t h e p i t s i t e s . The G r e a t e r V a n c o u v e r a r e a has been f o r t u n a t e i n t h e a b u n d a n c e o f good g r a v e l and s and d e p o s i t s w i t h i n e a s y t r a n s p o r t o f u r b a n c e n t r e s , and as a r e s u l t , has e n j o y e d some o f t h e l o w e s t - c o s t g r a v e l and s and d e p o s i t s i n N o r t h A m e r i c a . The C o q u i t l a m - P o r t Moody a r e a a l o n e has s u p p l i e d many t e n s o f m i l l i o n s o f c u b i c m e t e r s o f g r a v e l a t a v a l u e o f many m i l l i o n s o f d o l l a r s t o t h e G r e a t e r V a n c o u v e r a r e a f o r c o n -s t r u c t i o n p u r p o s e s . M u n i c i p a l z o n i n g r e g u l a t i o n s have c l o s e d t h e l a r g e s t g r a v e l and sand o p e r a t i o n i n B r i t i s h C o l u m b i a a t Mary H i l l . House s and a p a r t m e n t b u i l d i n g s w i l l p r o b a b l y c o v e r l a r g e r e s e r v e s o f V a s h o n and p r e - V a s h o n o u t w a s h d e p o s i t s and some C o w i c h a n Head F o r m a t i o n f l u v i a l g r a v e l and s a n d . W i t h f u r t h e r u r b a n d e v e l o p m e n t and l a n d r e z o n i n g o t h e r g r a v e l and s and o p e r a t i o n s may a l s o be p h a s e d o u t and more l a r g e r e s e r v e s c o v e r e d by b u i l d i n g s . G r a v e l and sand w i l l t h e n have t o be t r a n s p o r t e d f r o m a r e a s much f a r t h e r away f r o m t h e V a n c o u v e r a r e a , t h e r e b y g r e a t l y i n c r e a s i n g t r a n s p o r t a t i o n and p o s s i b l y m i n i n g c o s t s . O t h e r p r o b l e m s , r e l a t e d t o t h e s u r f i c i a l g e o l o g y o f t h e a r e a , t h a t m i g h t h i n d e r g r a v e l and sand e x c a v a t i o n a r e as f o l l o w s 1. E x c e s s i v e o v e r b u r d e n o f t i l l o r g l a c i o m a r i n e s t o n y c l a y e y s i l t . B o th a r e d i f f i c u l t t o remove w i t h a s h o v e l o r l o a d e r and b o t h p r e s e n t a d i s p o s a l p r o b l e m . 2. D i s c o n t i n u i t y o f g r a v e l and s and u n i t s , due t o i r r e g u -l a r b u r i e d l a n d s c a p e s b o u n d i n g t h e s t r a t a , c a u s i n g them t o r a n d o m l y s w e l l and p i n c h o u t ( F i g . 30 ) . D i s -c o n t i n u o u s g r a v e l l e n s e s i n d o m i n a n t l y sand u n i t s a l s o c a u s e p r o b l e m s i n g r a v e l r e s e r v e e s t i m a t i o n . 3. O v e r s i z e d b o u l d e r s up t o 5 m d i a . ( F i g . 21) i n g l a c i a l u n i t s , w h i c h c a n n o t be h a n d l e d by e q u i p m e n t w i t h o u t b l a s t i n g . h. O c c u r r e n c e s o f i n t e r b e d d e d t h i n f i n e sand and s i l t s t r a t a c an c a u s e p r o b l e m s i n w a s h i n g and s i z i n g , and w a s h o u t s i n s t e e p s l o p e s . 5. O c c u r r e n c e o f t i l l and s t o n y c l a y e y s i l t r i d g e s ( F i g . 30) b e t w e e n . s a n d and g r a v e l u n i t s . B o t h a r e d i f f i c u l t f o r m a c h i n e r y t o h a n d l e and when wet t h e y f o r m m u d h o l e s . I f t h e r i d g e s a r e h i g h , t h e y make t h e o v e r l y i n g g r a v e l and s and t o o t h i n t o m i n e e c o n o m i c a l l y . 6. H i g h g r o u n d w a t e r t a b l e s , p a r t i c u l a r l y t r o u b l e s o m e f o r a s m a l l o p e r a t o r w i t h o n l y a s h o v e l o r l o a d e r o p e r a t i o n . F o u n d a t i o n M a t e r i a l s and D r a i n a g e A r m s t r o n g (1957, 1961) s u m m a r i z e d c h a r a c t e r i s t i c s p e r t i -n e n t t o f o u n d a t i o n s o f t h e v a r i o u s P l e i s t o c e n e s e d i m e n t s f o u n d i n t h e F r a s e r L o w l a n d . A k n o w l e d g e o f t h e p r o p e r t i e s o f f o u n d -a t i o n m a t e r i a l s i s p a r t i c u l a r l y d e s i r a b 1 e w h e r e v e r t h e s t a b i l i t y 94. and d u r a b i l i t y o f s t r u c t u r e s may be a f f e c t e d by t h e n a t u r e o f u n d e r l y i n g m a t e r i a l s . The most i m p o r t a n t c o n s i d e r a t i o n i s w h e t h e r t h e s e d i m e n t s on w h i c h f o u n d a t i o n s a r e t o be b u i l t have been p r e l o a d e d by g l a c i e r i c e . Va shon t i l l and o l d e r d e p o s i t s have been p r e -l o a d e d by a t l e a s t 1800 m (5900 f t . ) o f i c e a t v a r i o u s t i m e s d u r i n g t h e P l e i s t o c e n e e p o c h , w h e r e a s p o s t - V a s h o n d e p o s i t s i n t h e C o q u i t l a m - P o r t Moody a r e a have been p r e l o a d e d o n l y by t h e w e i g h t o f t h e s e d i m e n t s o v e r l y i n g t h e m . Mos t t i l l s i n t h e a r e a a r e l o d g e m e n t t i l l s , d e p o s i t e d u n d e r ' g r e a t w e i g h t s o f i c e , and t h e y s h o u l d r e m a i n r e l a t i v e l y u n d e -f o r m e d u n d e r h e a v y l o a d s . In t i l l s f i n e p a r t i c l e s f i l l v o i d s b e t w e e n c o a r s e p a r t i c l e s and b i n d them t o g e t h e r t o f o r m a n a t u r a l p h y s i c a l c o n c r e t e . Thus t i l l s c an h a r d e n and become i m p e r v i o u s a g a i n , a f t e r s l i d i n g , o r a f t e r e x c a v a t i o n when u sed as f i l l . H o w e v e r , t h e y have v e r y p o o r d r a i n a g e . T i 1 1 - 1 i k e g l a c i o m a r i n e d e p o s i t s , h o w e v e r , we re f o r m e d by s t o n e s d r o p p i n g i n t o s e a - f l o o r muds f r o m d r i f t i n g i c e , and p o s t - V a s h o n g l a c i o m a r i n e d e p o s i t s ( i . e . t h o s e t h a t have n o t been p r e l o a d e d by i c e ) 'may f a i l when s u b j e c t e d e ven t o r e l a t i v e l y l i g h t l o a d s . Where p o s t - V a s h o n g l a c i o m a r i n e d e p o s i t s a t t a i n t h i c k n e s s e s o f a p p r o x i m a t e l y 5 m (15 f t . ) o r m o r e , m a j o r u r b a n and i n d u s t -r i a l d e v e l o p m e n t on t h e s e d e p o s i t s may e n c o u n t e r l o c a l s e t t l i n g and d r a i n a g e p r o b l e m s q u i t e u n l i k e t h o s e o f t h e t i l l s t h a t t h e y may r e s e m b l e 1 i t h o 1 o g i c a 1 1 y . E x a m p l e s i n t h e C o q u i t l a m - P o r t Moody a r e a a r e t h e C h i n e s H e i g h t s and H a r b o u r V i l l a g e s u b d i v i -s i o n s on t h e h i l l s i d e s o u t h o f t h e B a r n e t H i g h w a y , b e t w e e n t h e 95. c i t i e s o f P o r t Moody and P o r t C o q u i t l a m . In t h e s e s u b d i v i s i o n s some h o u s e s w e r e b u i l t on C a p i l a n o ( p o s t - V a s h o n ) f o s s i 1 i f e r o u s g l a c i o m a r i n e s t o n y c l a y e y s i l t s up t o 8 m (25 f t . ) t h i c k and a r e e x p e r i e n c i n g d r a i n a g e p r o b l e m s i n some p l a c e s and may e n c o u n t e r b e a r i n g p r o b l e m s . As t h e name i n d i c a t e s , C h i n e s H e i g h t s i s a s e r i e s o f w a s h o u t o r s l i d e g u l l i e s c a u s e d by e x c e s s i v e p o r e w a t e r p r e s s u r e b u i l t up i n t h e C a p i l a n o g l a c i o m a r i n e and u n d e r -l y i n g d e p o s i t s . He re t h e u n d e r l y i n g Quad ra Sands have washed o u t f r o m b e n e a t h t h e C a p i l a n o g l a c i o m a r i n e s e d i m e n t s , c a u s i n g them t o f a i l and e ven f l o w . Under t h e s e c o n d i t i o n s v e r y l i g h t l o a d s w o u l d c a u s e t h e s e s e d i m e n t s t o f a i l . G l a c i o m a r i n e d e p o -s i t s have v e r y low p e r m e a b i l i t i e s , w h i c h c o n t r o l downward d r a i n -a g e ; t h e r e f o r e , p o r e w a t e r p r e s s u r e s h o u l d be c o n t r o l l e d i n t h e s e (and u n d e r l y i n g ) d e p o s i t s w h e r e u r b a n o r i n d u s t r i a l d e v e l o p m e n t i s o c c u r r i n g , e s p e c i a l l y on h i l l s i d e s . A r m s t r o n g ( i i h 7 p r e p , and F i g . 1 o f t h i s t h e s i s ) has remapped t h e s u r f i c i a l d e p o s i t s i n t h e a r e a , i n c l u d i n g t h e d i s t r i b u t i o n o f C a p i l a n o g l a c i o m a r i n e s e d i m e n t s and Va shon t i l l . Ta b.l e . I I I (mod i f i ed a f t e r A r m s t r o n g , 1961) s u m m a r i z e s f o u n d -a t i o n and d r a i n a g e c h a r a c t e r i s t i c s o f P l e i s t o c e n e s e d i m e n t s f o u n d i n t h e C o q u i1 1 a m - P o r t Moody a r e a . A l l t h e m a t e r i a l s l i s t e d i n t h e t a b l e a r e e a s y t o e x c a v a t e e x c e p t f o r t h e t i l l s and t o a l e s s e r e x t e n t t h e g l a c i o m a r i n e d e p o s i t s . C o h e s i o n may be h i g h enough i n t h e t i l l s t o r e q u i r e b l a s t i n g and some o f t h e b o u l d e r s i n b o t h t h e t i l l and g l a c i o m a r i n e d e p o s i t s w i l l have t o be b r o k e n t o be r e m o v e d . TABLE III: FOUNDATION MATERIALS AND DRAINAGE, COQ.UITLAM-PORT MOODY AREA, B.C Type of Depos i t P re l oaded by G l a c i e r Ice Bea r i n g Va lue for Founda t i ons Dra inage T i l l : Vashon, Semiahmoo? yes exce l l en t s u r f a c e d ra inage on l y Sand and G r a v e l : Vashon (where o v e r l a i n by t i l l ) , Cowichan Head, Semiahmoo?, H i gh -bury lf Westl ynn? yes good to e x c e l l e n t e x c e l l e n t downward and l a t e r a l Sand and G r a v e l : C a p i l a n o , Vashon (where not o v e r -l a i n by t i l l ) no good e x c e l l e n t downward and l a t e r a l except where groundwater t a b l e near s u r f a c e G l a c i o m a r i n e s tony c l a y e y s i l t : Port C o q u i t l a m , Semiahmoo? yes f a i r to good very poor downward and l a t e r a l d ra inage G l a c i o m a r i n e stony c l a y e y s i l t and ma r i ne c1ayey s i l t : no poor to f a i r ; may have e x c e s s i v e se 111emen t s s u r f a c e dra inage on ly Ca p i1 a no G 1 a c i o 1 a c u s t r i n e l am ina ted s tony s i l t : Vashon (where o v e r l a i n by t i l l ) , Sem i a hmoo ? yes f a i r to good very poor downward and l a t e r a l d ra inage Medium to c o a r s e sand: Ho 1 o c e n e - - d e p o s i t e d by modern streams in low f l a t - l y i n g a reas no f a i r to good, depending on d e n s i t y poor most of the year as g round -water t a b l e near s u r f a c e F ine sand, s i l t , and c l a y : Ho 1 o c e n e - - d e p o s i t e d by modern streams in low f l a t - l y i n g areas no very poor to f a i r ; in areas under -l a i n by mos t l y s i l t and c l a y e x c e s -s i v e s e t t l e m e n t s may o c c u r ; areas u n d e r l a i n by most ly f i n e sand and s i l t a re s u s c e p t i b l e to 1 i q u e f i c a t i o n s u r f a c e dra inage on ly F o s s i l pea t , o r g a n i c f i n e sand, s i l and c l a y : Quadra (m ino r ) , Cowichan Head, Highbury? t yes poor to f a i r very poor downward and l a t e r a l d ra inage Peat , o r g a n i c f i n e sand, s i l t , and c l a y : Ho 1ocene- -modern bog and swamp depos i t s no p re l oad e x t e n s i v e l y or remove from f o u n d a t i o n s ; undergoes extreme compact ion and e x c e s s i v e s e t t l i n g occur s very d i f f i c u l t ; peat ho lds up to 26 t imes i t s own weight of water CTl 97. Sewage D i sposa1 W h e r e v e r sewage d i s p o s a l i s d e p e n d e n t on s e p t i c t a n k s , d r a i n a g e and s u b - s o i l c o n d i t i o n s must be c o n s i d e r e d . Ma r y H i l l and t h e s l o p e s o f M a i l l a r d v i l l e , E s s o n d a l e , H a r b o u r up/and V i l l a g e , H a r b o u r C h i n e s , P o r t Moody, and t he^no r t hea s t, o f l o c o a r e c o v e r e d w i t h C a p i l a n o g l a c i o m a r i n e s e d i m e n t s and V a s h o n t i l l . T h e s e d e p o s i t s p e r m i t a l m o s t no downward d r a i n a g e . In p l a c e s t h e y a r e m a n t l e d by a t h i n l a y e r o f C a p i l a n o s u p r a -l i t t o r a l l a g g r a v e l a n d / o r C a p i l a n o l i t t o r a l s and w h i c h p e r m i t downward d r a i n a g e t o t h e i m p e r v i o u s m a t e r i a l s u n d e r l y i n g t h e m ; h o w e v e r , d u r i n g t h e r a i n y s e a s o n s t h e g r o u n d w a t e r t a b l e i s n e a r t h e s u r f a c e o f t h e t h i n sand and g r a v e l m a n t l e and d r a i n a g e becomes v e r y p o o r . Much o f t h e o v e r f l o w f r o m s e p t i c t a n k a b s o r p t i o n f i e l d s i n t h e s e u p l a n d a r e a s m u s t , t h e r e f o r e , e v e n -t u a l l y d r a i n d o w n s ] o p e by s u r f a c e and n e a r - s u r f a c e r u n o f f . The u p l a n d n o r t h e a s t o f l o c o and t h e s o u t h e r n u p p e r s l o p e s o f B u r k e M o u n t a i n , w h e r e b e d r o c k i s a t o r n e a r t h e g r o u n d s u r f a c e , have o n l y s u r f a c e d r a i n a g e and a r e n o t f a v o u r a b l e f o r s e p t i c t a n k i n s t a l l a t i o n . I f s e p t i c t a n k s must be u s ed u n d e r t h e s e u n f a v o u r -a b l e c o n d i t i o n s , t h e y s h o u l d be p l a c e d s u f f i c i e n t l y f a r a p a r t so as no t t o a f f e c t d e v e l o p m e n t on a d j a c e n t l o t s . Mary H i l l , t h e s l o p e s o f M a i l l a r d v i l l e e t c . e a s t o f B u r n a b y M o u n t a i n , and t h e bench on t h e w e s t s i d e o f t h e l o w e r C o q u i t l a m v a l l e y a r e u n d e r l a i n by V a s h o n t i l l and C a p i l a n o g l a c i o m a r i n e s e d i m e n t s w h i c h o v e r l i e Va shon o r Quad ra g r a v e l and s a n d . In t h e s e a r e a s some downward d r a i n a g e can be a c c o m p l i s h e d by p u t t i n g d r a i n a g e h o l e s t h r o u g h t h e o v e r l y i n g i m p e r v i o u s m a t e r i a l ; how-e v e r , t h i s s h o u l d no t be done w h e r e g r o u n d w a t e r c o n t a m i n a t i o n 98. i s a p r o b l e m . In t h e l o w e r C o q u i t l a m v a l l e y , 2-3 km n o r t h o f t h e Lougheed Hwy. , C a p i l a n o p e r m e a b l e sand and g r a v e l f o r m t e r r a c e s w h i c h p e r m i t e a s y downward c i r c u l a t i o n o f s e p t i c t a n k e f f l u e n t e x c e p t w h e r e t h e g r o u n d w a t e r t a b l e i s n e a r t h e s u r f a c e . A g a i n , w h e r e g r o u n d w a t e r c o n t a m i n a t i o n i s a p r o b l e m , c a r e must be t a k e n i n t h e c o n s t r u c t i o n and s p a c i n g o f s e p t i c t a n k s , and t h e g r o u n d -w a t e r s u p p l y c h e c k e d p e r i o d i c a l l y f o r c o n t a m i n a t i o n . In t h e C o q u i t l a m R i v e r v a l l e y b e t w e e n E s s o n d a l e and Mary H i l l , i n t h e l o w l a n d s o u t h o f M a i l l a r d v i l l e , and i n t h e l o w l a n d a r e a a t P o r t Moody , s e p t i c t a n k sewage d i s p o s a l w i l l n o t o p e r a t e s a t i s f a c t o r i l y w h e r e t h e g r o u n d w a t e r t a b l e i s a t o r c l o s e t o t h e a b s o r p t i o n t i l e , o r i n p l a c e s t h a t a r e p e r i o d i c a l l y f l o o d e d , e s p e c i a l l y d u r i n g r a i n y s e a s o n s . F l o o d C o n t r o l F l o o d i n g i s n o t a s e r i o u s p r o b l e m i n t h e C o q u i t l a m - P o r t Moody a r e a . Dykes a l o n g t h e F r a s e r R i v e r a r e e f f e c t i v e i n c o n t r o l l i n g i t . The C o q u i t l a m R i v e r f l o o d s f r e q u e n t l y b e t w e e n E s s o n d a l e and Mary H i l l n e a r i t s mouth and m o u n t a i n s t r e a m s n o r t h o f t h e c i t i e s o f P o r t Moody and P o r t C o q u i t l a m o c c a s i o n -a l l y f l o o d . V e g e t a t i v e c o v e r , c h e c k dams, and o t h e r m e a s u r e s a r e u sed e f f e c t i v e l y t o m i n i m i z e d e s t r u c t i o n c a u s e d by f l o o d i n g i n t h e C o q u i t l a m - P o r t Moody a r e a . S l i d e s and Washou t s L a r g e s l i d e s have o c c u r r e d i n t h e a r e a o v e r t h e y e a r s , m a i n l y on s t e e p s l o p e s u n d e r u n s t a b l e s o i l c o n d i t i o n s c a u s e d by heavy r a i n f a l l and e x c e s s i v e l a n d c l e a r i n g . 99. The s t e e p w e s t s l o p e o f t h e l o w e r C o q u i t l a m R i v e r v a l l e y n o r t h o f t h e Lougheed Hwy. has u n d e r g o n e much s l i d i n g due t o h e a v y r a i n f a l l s and human a c t i v i t y . Wa shou t s due t o o v e r l o a d e d w a t e r t a b l e s and w a t e r d r a i n i n g o u t o f t h i s s l o p e t h r o u g h p e r v i o u s f i n e s e d i m e n t l a y e r s , c a u s i n g o v e r l y i n g m a t e r i a l s t o f a i l and s l i d e , have been d o c u m e n t e d by A r m s t r o n g ( 1 9 5 7 ) - L a r g e n a t u r a l s i i d e s c a r s a l s o o c c u r n e a r t h e G r e a t e r V a n c o u v e r W a t e r -shed G a t e s b e l o w C o q u i t l a m L a k e . A t P o r t Moody A r m s t r o n g (1957 ) d i s c o v e r e d a m a j o r s l i d e a t l e a s t 100 y e a r s o l d i n a b u i l d i n g e x c a v a t i o n . The s l i d e was p r o b a b l y c a u s e d by e x c e s s i v e r a i n -f a l l d u r i n g a r a i n y s e a s o n and t h e m a t e r i a l came o u t o f t h e g u l l i e s a t C h i n e s H e i g h t s . In 1953 a l a r g e w a s h o u t o c c u r r e d a t t h e Mary H i l l g r a v e l p i t on t h e s o u t h s l o p e o f t h e h i l l . I t o c c u r r e d d u r i n g g r a v e l e x c a v a t i o n when t h e s h o v e l c u t t h r o u g h a t h i n s i l t b e d , t a p p i n g a b u r i e d w a t e r r e s e r v o i r , w h i c h was o v e r l a i n by two Va shon t i l l s h e e t s s e p a r a t e d by o u t w a s h g r a v e l s . The s a t u r a t e d s i l t l a y e r became a m u d f l o w and a l a r g e p i t was e x c a v a t e d by t h e s l i d e . As p r e v i o u s l y m e n t i o n e d , p o r e w a t e r p r e s s u r e i n p o o r l y d r a i n e d f i n e s e d i m e n t s (and u n d e r l y i n g s e d i m e n t s ) i n t h e a r e a must be m o n i t o r e d and c o n t r o l l e d w h e r e s t e e p s l o p e s o c c u r , e s p e c i a l l y d u r i n g r a i n y s e a s o n s and w h e r e u r b a n and i n d u s t r i a l d e v e l o p m e n t i s t a k i n g p l a c e . A r e a s o f l ow s l o p e s t a b i l i t i e s , and t h e r e f o r e , p o t e n t i a l s l i d e a r e a s , w i t h i n t h e C o q u i t l a m -P o r t Moody a r e a o c c u r a l o n g t h e w e s t bank o f t h e l o w e r C o q u i t -lam R i v e r v a l l e y , t h e n o r t h s i d e o f t h e u p l a n d b e t w e e n P o r t Moody, H a r b o u r V i l l a g e and Ma i11 a r d v i 1 1 e , t h e w e s t and s o u t h . TOO. s l o p e s o f Mary H i l l , and a s m a l l , s t e e p , a r e a on t h e s o u t h s l o p e o f M a i l l a r d v i l l e . L e s s h a z a r d o u s a r e a s a r e t h e e a s t s i d e o f t h e l o w e r C o q u i t l a m R i v e r v a l l e y ( u n d e r l a i n m o s t l y by b e d -r o c k ) , on t o p o f t h e g e n t l y s l o p i n g bench on t h e w e s t s i d e , t h e e a s t and n o r t h s l o p e s o f Mary H i l l , t h e l o w e r s l o p e s o f B u r k e M o u n t a i n , t h e l o c o a r e a , and n e a r t h e t o p o f t h e u p l a n d b e t w e e n P o r t Moody , H a r b o u r V i l l a g e , and M a i l l a r d v i l l e , w h e r e s l o p e s a r e g e n t l e . S t a b l e a r e a s a r e t h e u p p e r s l o p e s o f B u r k e M o u n t a i n and a b o v e l o c o , w h e r e b e d r o c k i s a t o r n e a r t h e s u r f a c e , t h e l o w e r r e a c h e s o f C o q u i t l a m R i v e r and o t h e r f l a t a r e a s a r o u n d P o r t C o q u i t l a m and P o r t Moody ( h o w e v e r s e t t l i n g may o c c u r on p e a t b o g s ) , and on t o p o f t h e u p l a n d s a t Mary H i l l and b e t w e e n P o r t Moody , H a r b o u r V i l l a g e , and M a i l l a r d v i l l e . The t o p s o f t h e u p l a n d s a r e e x c e l l e n t f o r b u i l d i n g f o u n d a t i o n s as t h e y a r e u n d e r -l a i n by g l a c i e r - l o a d e d t i l l and t h e y have h i g h s l o p e ; s t a b i l i t y ; h o w e v e r , s u r f a c e and downward d r a i n a g e may be a p r o b l e m . 1 0 1 . CHAPTER E IGHT: CONCLUSIONS A. Q u a t e r n a r y G e o l o g y E x p o s e d Q u a t e r n a r y s e d i m e n t s i n t h e C o q u i t l a m - P o r t Moody a r e a i n d i c a t e i t has been s u b j e c t e d t o two and p o s s i b l y t h r e e g l a c i a t i o n s , r e p r e s e n t e d by d r i f t d e p o s i t s , s e p a r a t e d by n o n -g l a c i a l i n t e r v a l s w h i c h a r e r e p r e s e n t e d by o r g a n i c s e d i m e n t s . Each m a j o r i c e a d v a n c e and r e t r e a t was a c c o m p a n i e d by e u s t a t i c and i s o s t a t i c s e a - l e v e l c h a n g e s o f up t o 230 m, r e l a t i v e t o p r e s e n t sea l e v e l , and p r o b a b l y t e c t o n i c a d j u s t m e n t s . Two o r t h r e e l o c a l a d v a n c e s and r e t r e a t s we re a s s o c i a t e d w i t h e a c h m a j o r a d v a n c e . D u r i n g t h e l a s t m a j o r g l a c i a t i o n two s t a d e s ( s m a l l e r g l a c i a l i n t e r v a l s w i t h i n t h e m a j o r g l a c i a t i o n ) o c c u r -r e d , p o s s i b l y s e p a r a t e d by an i n t e r s t a d e (an i n t e r v a l i n t h e g l a c i a t i o n warmer t h a n t h e s t a d e s , i n t h i s c a s e , d u r i n g w h i c h p e a t f o r m e d ) . C o q u i t l a m D r i f t , i d e n t i f i e d d u r i n g t h i s s t u d y , r e p r e s e n t s t h e e a r l i e r s t a d e and has no t been r e c o g n i z e d b e f o r e on t h e B.C. m a i n l a n d . M a r i n e i n v a s i o n o c c u r r e d i n t h e a r e a a t l e a s t t h r e e t i m e s d u r i n g t h e P l e i s t o c e n e e p o c h , and i s r e p r e -s e n t e d by f o s s i 1 i f e r o u s m a r i n e and g l a c i o m a r i n e d e p o s i t s . N i n e f o r m a t i o n a l 1 i t h o s t r a t i g r a p h i c u n i t s have been d e s -c r i b e d i n t h e a r e a , e a c h p r o b a b l y r e p r e s e n t i n g a g e o l o g i c -c l i m a t i c u n i t , and t h e f o l l o w i n g s u c c e s s i o n has been e s t a b l i s h e d : H o l o c e n e S e d i m e n t s (11,000 y r . B . P . - p r e s e n t ) ; F r a s e r G l a c i a t i o n ( L a t e W i s c o n s i n , 26,000-11,000): C a p i l a n o S e d i m e n t s , V a s h o n D r i f t , Quad ra S a n d , and C o q u i t l a m D r i f t ; O l y m p i a N o n g l a c i a l I n t e r v a l ( M i d d l e W i s c o n s i n , 60,0007-26 , 000) : C o w i c h a n Head F o r m a t i o n ; M a j o r G l a c i a t i o n ( M i d d l e o r E a r l y W i s c o n s i n , p r o b -1 0 2 . a b l y > 6 2 , 0 0 0 ) : Semiahmoo? D r i f t ; M a j o r N o n g l a c i a l I n t e r v a l ( E a r l y W i s c o n s i n ? , p r o b a b l y > 6 2 , 0 0 0 ) : H i g h b u r y ? S e d i m e n t s ; M a j o r G l a c i a t i o n ? ( E a r l y o r P r e - W i s c o n s i n , > 6 2 , 0 0 0 ) : W e s t l y n n D r i f t ? T h e s e u n i t s a r e s e p a r a t e d by u n c o n f o r m i t i e s r e p r e s e n t -i n g b u r i e d l a n d s c a p e s w h i c h we re l a t e r m o d i f i e d by s t r e a m a n d / o r i c e a c t i o n . D u r i n g t h e d e p o s i t i o n o f e a c h f o r m a t i o n a l s e d i m e n t u n i t f o r m e r l a n d s c a p e s we re r e s h a p e d and new one s f o r m e d . The C o q u i t l a m v a l l e y s e d i m e n t f i l l was c a r v e d o u t and t h e u p l a n d s i n t h e a r e a r e m o d e l l e d s e v e r a l t i m e s d u r i n g Q u a t e r n a r y t i m e . C o n s e q u e n t l y , t h e u n r a v e l l i n g o f t h e s t r a t i g r a p h i c s u c c e s s i o n becomes v e r y c o m p l e x , e s p e c i a l l y a s l i t h o l o g i c u n i t s o f d i f f e r -e n t c h r o n o l o g i c a ge s may c l o s e l y r e s e m b l e one a n o t h e r and may be i m p o s s i b l e t o s e p a r a t e w i t h o u t a b s o l u t e c h r o n o l o g i c age s o r c o m p l e t e s t r a t i g r a p h i c s e c t i o n s . S e d i m e n t u n i t s o c c u r s p o r a d i -c a l l y b e c a u s e o f t h e d e v e l o p m e n t o f b u r i e d l a n d s c a p e s and c o r : r e l a t i o n s made on o t h e r t h a n a t h r e e - d i m e n s i o n a l s t u d y a r e a t b e s t t e n t a t i v e and s h o u l d be s u p p o r t e d w h e r e v e r p o s s i b l e by r a d i o c a r b o n d a t e s . Thus a s t u d y b a s e d p u r e l y on d r i l l h o l e i n f o r m a t i o n may l e a d t o c o m p l e t e l y m i s l e a d i n g c o n c l u s i o n s . In some p l a c e s i n t h e a r e a a d r i l l h o l e c o u l d p e n e t r a t e more t h a n 15 d i f f e r e n t s e d i m e n t l a y e r s , and i n o t h e r s , o n l y a few m e t e r s away , a s few as t w o . " Q u a d r a " s e d i m e n t s have i n t h e p a s t been c o n s i d e r e d as n o n g l a c i a l o r i n t e r g l a c i a l d e p o s i t s ( A r m s t r o n g and B r o w n , 1 9 5 3 ; F y l e s , 1 963 ; A r m s t r o n g , 1 9 6 5 ) . C l a g u e (1976 ) p r o p o s e d , and t h e p r e s e n t w r i t e r a g r e e s , t h a t Quad ra Sand i s p r o g l a c i a l ( d i s t a l ) 103. o u t w a s h d e p o s i t e d by m e l t w a t e r d e r i v e d f r o m Va shon i c e . How-e v e r , as a 1 i t h o s t r a t i g r a p h i c u n i t Quad ra Sand has been mapped s e p a r a t e l y f r o m Va shon D r i f t , a s A r m s t r o n g , e t a l . ( 1965 ) have d e f i n e d Quad ra s e d i m e n t s t o be t h e l o w e r b o u n d i n g s t r a t a f o r V a s h o n D r i f t . The p r e s e n t w r i t e r s u g g e s t s t h a t i n t h e C o q u i t -l a m - P o r t Moody a r e a p r o g l a c i a l Quad ra Sand d e p o s i t i o n , by s t r e a m s d e r i v e d f r o m s o u t h w a r d - a d v a n c i n g Va shon ? i c e t o t h e n o r t h i n t h e C o a s t M o u n t a i n s , s t a r t e d e a r l y d u r i n g t h e F r a s e r G l a c i a t i o n a b o u t 2 5 , 8 0 0 y e a r s a g o . I t was i n t e r r u p t e d by w e s t w a r d - a d v a n c i n g C o q u i t l a m i c e w h i c h b l o c k e d t h e mouth o f t h e C o q u i t l a m v a l l e y w h i l e Quad ra Sand was d e p o s i t e d b e h i n d t h e i c e dam up t o 250 m a . s . l . a b o u t 2 1 , 6 0 0 y e a r s a g o . Quad ra Sand d e p o s i t i o n c o n t i n u e d i n t h e C o q u i t l a m - P o r t Moody a r e a d u r i n g t h e r e t r e a t o f C o q u i t l a m i c e , w h i c h o c c u r r e d by 1 8 , 6 0 0 y r . B . P . , when p e a t was g r o w i n g a t Mary H i l l . D u r i n g t h i s t i m e V a s h o n i c e a d v a n c e d f u r t h e r s o u t h t o w a r d s t h e a r e a and m e l t w a t e r s t r e a m s c a r v e d o u t much o f t h e Quadra f i l l i n t h e C o q u i t l a m v a l l e y and r e d e p o s i t e d i t i n t h e F r a s e r L o w l a n d . The t o p o g r a p h y o f t h e a r e a has r e m a i n e d b a s i c a l l y t h e same s i n c e Semiahmoo? t i m e and has been m o d i f i e d o n l y l o c a l l y by t h e r e s h a p i n g o f o l d e r l a n d s c a p e s . The p r e - S e m i a h m o o ? s t r a t i g r a p h i c r e c o r d i s t o o s p a r c e t o comment on t h e P l e i s t o c e n e t o p o g r a p h y b e f o r e t h a t t i m e . E n g i n e e r i n g and E n v i r o n m e n t a l G e o l o g y Outwash s and and g r a v e l a r e t h e most e x t e n s i v e s o u r c e s o f g r a n u l a r a g g r e g a t e f o r c o n s t r u c t i o n p u r p o s e s . V a s h o n o u t w a s h i s t h e most a c c e s s i b l e and commonly m i n e d g r a v e l d e p o s i t ; h o w e v e r , 104. Semiahmoo? and W e s t l y n n ? o u t w a s h a r e o f e q u a l l y h i g h q u a l i t y b u t t h e y a r e u s u a l l y t o o d e e p l y b u r i e d t o be e c o n o m i c . T h e s e l a t t e r d e p o s i t s a r e f o u n d b u r i e d i n u p l a n d s u n d e r l a i n by t h i c k Q u a t e r n a r y d e p o s i t s ( e . g . Mary H i l l ) , and i n r i v e r bank s i n Q u a t e r n a r y s e d i m e n t f i l l s o c c u p y i n g v a l l e y s i n t h e C o a s t M o u n -t a i n s w h i c h b o r d e r t h e F r a s e r L o w l a n d ( e . g . l o w e r C o q u i t l a m R i v e r v a l l e y ) . R a i s e d d e l t a and a l l u v i a l f l o o d p l a i n g r a v e l s a r e t h e b e s t s o r t e d b u t a r e c o n f i n e d t o t h e mouth s o f m o u n t a i n v a l l e y s , o r b u r i e d i n u p l a n d s and m o u n t a i n v a l l e y s e d i m e n t f i l l s . S u p r a l i t t o r a l l a g g r a v e l i s w i d e s p r e a d and u n d e r l i e s u p l a n d s u r f a c e s b u t i s u s u a l l y t o o t h i n , muddy, and i r o n s t a i n e d t o be e c o n o m i c . Mode rn r i v e r g r a v e l d e p o s i t e d by s t r e a m s f l o w i n g o u t o f t h e C o a s t M o u n t a i n s , and c u t t i n g t h r o u g h and r e d e p o s i t i n g Q u a t e r n a r y s e d i m e n t s , i s a l s o a good s o u r c e f o r g r a n u l a r a g g r e -g a t e ( e . g . C o q u i t l a m R i v e r g r a v e l ) . Where one u n e c o n o m i c g r a v e l t y p e d i r e c t l y o v e r l i e s a n o t h e r t h e c o m b i n a t i o n may become m i n e -a b l e ( e . g . C a p i l a n o s u p r a l i t t o r a l o v e r l y i n g t h i n V a s h o n o u t w a s h ) . Some p r o b l e m s e n c o u n t e r e d by p i t o p e r a t o r s w i l l be t h e r e m o v a l o f o v e r b u r d e n , e s p e c i a l l y t i l l and g l a c i o m a r i n e d e p o s i t s ; t h e i r r e g u l a r d i s t r i b u t i o n o f p i t r u n due t o b u r i e d l a n d s c a p e s ; and e s p e c i a l l y m u n i c i p a l u r b a n and i n d u s t r i a l r e z o n i n g o f l a n d u n d e r l a i n by good g r a v e l r e s e r v e s . Land s u r f a c e s o f l ow s l o p e w h i c h a r e u n d e r l a i n by b e d r o c k and by s e d i m e n t s t h a t have been p r e - l o a d e d by g l a c i e r i c e ( Va shon D r i f t and o l d e r s e d i m e n t s ) a r e b e s t l o c a t i o n s f o r b u i l d i n g s and r o a d s ; h o w e v e r , d r a i n a g e may be p o o r w h e r e b e d r o c k , t i l l , o r g l a c i o m a r i n e d e p o s i t s a r e a t o r n e a r t h e s u r f a c e . 105. C a p i l a n o g l a c i o m a r i n e s e d i m e n t s have no t been p r e - l o a d e d by g l a c i e r i c e and c a n c a u s e s e r i o u s s e t t l i n g and d r a i n a g e p r o b l e m s f o r e n g i n e e r s and c o n t r a c t o r s w h e r e t h e s e d e p o s i t s become t h i c k . When t h e s e s e d i m e n t s become w a t e r s a t u r a t e d , t h e y c an f l o w e ven on v e r y s m a l l s l o p e s . T h i s i s e s p e c i a l l y t r u e on s t e e p s l o p e s w h e r e p o r e w a t e r p r e s s u r e i n t h e u n d e r l y i n g s e d i m e n t s becomes h i g h , u n d e r l y i n g p e r v i o u s s t r a t a may wash o u t as w a t e r d r a i n s t h r o u g h t h e m , and t h e o v e r l y i n g g l a c i o m a r i n e s e d i m e n t may f a i l and f l o w . Sewage d i s p o s a l by s e p t i c t a n k s i s a p r o b l e m i n a r e a s u n d e r l a i n by i m p e r v i o u s t i l l , g l a c i o m a r i n e s e d i m e n t s , and b e d r o c k , and w h e r e t h e g r o u n d w a t e r t a b l e i s n e a r t h e s u r f a c e . C o n s i d e r a t i o n must a l s o be g i v e n t o g r o u n d w a t e r c o n t a m i n a t i o n when i n s t a l l i n g s e p t i c t a n k s . F l a t a r e a s u n d e r l a i n by p e a t bogs po se s e r i o u s s e t t l i n g , d r a i n a g e , and sewage d i s p o s a l p r o b l e m s t o u r b a n and i n d u s t r i a l d e v e l o p m e n t . F l o o d i n g has no t been a s e r i o u s p r o b l e m i n t h e a r e a . C. R e c o m m e n d a t i o n s f o r F u r t h e r S t u d y 1. D e t a i l e d s t r a t i g r a p h i c and s e d i m e n t o 1 o g i c a 1 s t u d y o f p r e - V a s h o n P l e i s t o c e n e s e d i m e n t s e l s e w h e r e i n t h e F r a s e r Low-l a n d and a d j a c e n t r e g i o n s t o wo rk o u t t h e c o r r e l a t i o n and h i s t o r y o f t h e s e s e d i m e n t s , a i d e d by r a d i o c a r b o n d a t i n g , p a l y -n o l o g y , m i c r o p a 1 eon t o 1ogy , and f o s s i l i n s e c t s t u d i e s . 2. D e t a i l e d s e d i m e n t o 1 o g i c a 1 and s t r a t i g r a p h i c s t u d y o f V a s h o n D r i f t w i t h e m p h a s i s on f a c i e s r e l a t i o n s h i p s o f t h e i c e -c o n t a c t depo s i t s . 3. Pa 1 y n o 1 o g i c a 1 and f o s s i l i n s e c t s t u d i e s o f t h e s e d i m e n t s c o n t a i n i n g o r g a n i c m a t e r i a l s . 106. k. D e t a i l e d c o m p a r a t i v e s t u d y o f g l a c i o m a r i n e and t i l l d e p o s i t s i n c l u d i n g : p e b b l e f a b r i c , c h e m i c a l , b u l k d e n s i t y , m i n e r a l o g i c , g r a i n s i z e and r o u n d n e s s , p e n e t r a t i o n , A t t e r b e r g , and o t h e r a n a l y s e s . 5- D e t a i l e d s t u d y on t h e c a u s e o f d i s i n t e g r a t i o n o f some g r a n i t i c s t o n e s c o m p a r e d t o i n t a c t g r a n i t i c s t o n e s f o u n d i n j u x t a p o s i t i o n i n t h e Q u a t e r n a r y s e d i m e n t s i n t h e a r e a . 6. D e t a i l e d s t u d y o f p o t e n t i a l e n g i n e e r i n g and e n v i r o n -m e n t a l p r o b l e m s t o c o n s t r u c t i o n i n t h e C o q u i t l a m - P o r t Moody a r e a i n v o l v i n g t h e s t u d y o f c a s e h i s t o r i e s and f i e l d wo rk t o p r o d u c e " h a z a r d " maps f o r t h e a r e a . 1 0 7 . REFERENCES CITED A r m s t r o n g , J . E. , 19 5 3 : G e o l o g y o f Sand and G r a v e l D e p o s i t s i n Lower F r a s e r V a l l e y , B r i t i s h C o l u m b i a ; C a n . , M i n . , M e t . B u l l . , A p r i l , 1953, PP- 1-8. A r m s t r o n g , J . E. , 1957: S u r f i c i a l G e o l o g y o f New W e s t m i n s t e r M a p - A r e a , B r i t i s h C o l u m b i a ; G e o l . S u r v . C a n . , P a p . 5 7 ~ 5 and Map 16-1957-A r m s t r o n g , J . E. , 1961 : S o i l s o f t h e C o a s t a l A r e a o f S o u t h -w e s t B r i t i s h C o l u m b i a : j_n_ L e g g e t , R. F. ( e d . ) : S o i l s i n C a n a d a ; R o y a l S o c . C a n . , S p e c . P u b l . N o . 3, pp - 22~32. A r m s t r o n g , J . E. , 1 965: S t o p 1 3 _ 2 : j_n_ G u i d e b o o k f o r F i e l d C o n f e r e n c e J , P a c i f i c N o r t h w e s t , I . N . Q . U . A . , V l l t h C o n g r e s s , USA, pp . 106-107; p u b l . N e b r a s k a A c a d . S c i . A r m s t r o n g , J . E. , 1975a: Q u a t e r n a r y G e o l o g y , S t r a t i g r a p h i c S t u d i e s , and R e v a l u a t i o n o f T e r r a i n I n v e n t o r y Map s , F r a s e r L o w l a n d , B r i t i s h C o l u m b i a ; G e o l . S u r v . C a n . , P a p . 75-1, P t . A, pp . 377-380. A r m s t r o n g , J . E. , 1975b: F r a s e r L o w l a n d - - C a n a d a : j_n_ E a s t e r b r o o k , D. J . ( e d . ) : The L a s t G l a c i a t i o n : G u i d e -book f o r F i e l d C o n f e r e n c e , S e p t . 7 ~ 1 7 > I n t . G e o l . C o r r e l . P r o g . " Q u a t e r n a r y G l a c i a t i o n s i n t h e N o r t h e r n H e m i s p h e r e , " pp . 7^-97; p u b l . G e o l o g y D e p t . , W e s t e r n W a s h i n g t o n S t a t e C o l l e g e . A r m s t r o n g , J . E. : P o s t - V a s h o n W i s c o n s i n G l a c i a t i o n , F r a s e r L o w l a n d , B r i t i s h C o l u m b i a , C a n a d a ; subm. t o G e o l . S u r v . C a n . , i n p r e s s . A r m s t r o n g , J . E.: M i d d l e W i s c o n s i n and O l d e r P l e i s t o c e n e D e p o s i t s i n t h e F r a s e r L o w l a n d , B r i t i s h C o l u m b i a ; t o be subm. t o G e o l . S u r v . C a n . , i n p r e p . A r m s t r o n g , J . E . : S u r f i c i a l G e o l o g y , New W e s t m i n s t e r Map S h e e t ; u p d a t e d v e r s i o n o f A r m s t r o n g , 1957, t o be subm. t o G e o l . S u r v . C a n . , i n p r e p . A r m s t r o n g , J . E. and B r o w n , W. L . , 1953= G r o u n d - w a t e r R e s o u r c e s o f S u r r e y M u n i c i p a l i t y , B r i t i s h C o l u m b i a ; G e o l . S u r v . C a n . , W a t e r S u p p l y P a p e r 322. A r m s t r o n g , J . E. and B r o w n , W. L . , 1954: L a t e W i s c o n s i n M a r i n e D r i f t and A s s o c i a t e d S e d i m e n t s o f t h e Lower F r a s e r V a l l e y , B r i t i s h C o l u m b i a , C a n a d a ; B u l l . G e o l . S o c . Am. , V o l . 65, pp . 349-364. 108. A r m s t r o n g , J . E. and C l a g u e , J . J . : Two New Q u a t e r n a r y L i t h o -s t r a t i g r a p h i c U n i t s i n S o u t h w e s t e r n B r i t i s h C o l u m b i a ; subm. t o G e o l . S u r v . C a n . , i n p r e s s . A r m s t r o n g , J . E. , C r a n d e l l , D. R., E a s t e r b r o o k , D. J . , and N o b l e , J . B., 1 965 : L a t e P l e i s t o c e n e S t r a t i g r a p h y and C h r o n -o l o g y i n S o u t h w e s t e r n B r i t i s h C o l u m b i a and N o r t h w e s t e r n W a s h i n g t o n ; B u l l . G e o l . S o c . Am. , V o l . 7 6 , pp . 3 2 1 - 3 3 0 . A r m s t r o n g , J . E. and H i c o c k , S. R., 1 975 : Q u a t e r n a r y L a n d s c a p e s : P a s t and P r e s e n t - - a t Mary H i l l , C o q u i t l a m , B r i t i s h C o l u m b i a ; G e o l . S u r v . C a n . , P a p . 7 5 - 1 , P t . B, pp . 9 9 - 1 0 3 . A r m s t r o n g , J . E. and H i c o c k , S. R., 1 976 : Q u a t e r n a r y M u l t i p l e V a l l e y D e v e l o p m e n t o f t h e Lower C o q u i t l a m V a l l e y , C o q u i t l a m , B r i t i s h C o l u m b i a ; G e o l . S u r v . C a n . , P ap . 7 6 - I , P t . B, i n p r e s s . A r m s t r o n g , J . E. and H i c o c k , S. R.: C o q u i t l a m D r i f t : An E a r l y F r a s e r ( L a t e W i s c o n s i n ) I ce A d v a n c e i n t h e F r a s e r L o w l a n d , B r i t i s h C o l u m b i a ; t o be subm. t o J . Q u a t e r n a r y R e s e a r c h , i n p r e p . B u r w a s h , E. M. J . , 1919 : The G e o l o g y o f V a n c o u v e r and V i c i n i t y ; U n i v . C h i c a g o P r e s s , 106 pp . C l a g u e , J . J . , 1 976 : Quad ra Sand and i t s R e l a t i o n t o t h e L a t e W i s c o n s i n G l a c i a t i o n o f S o u t h w e s t e r n B r i t i s h C o l u m b i a ; subm. t o Can . J . E a r t h S c i . , i n p r e s s . E a s t e r b r o o k , D. J . , 1969 : P l e i s t o c e n e C h r o n o l o g y o f t h e P u g e t L o w l a n d and San J u a n I s l a n d s , W a s h i n g t o n ; B u l l . G e o l . S o c . Am. , V o l . 8 0 , pp . 2 2 7 3 - 2 2 8 6 . F u l t o n , R. J . and H a l s t e a d , E. C . , 1 972 : Q u a t e r n a r y G e o l o g y o f t h e S o u t h e r n C a n a d i a n C o r d i l l e r a : G u i d e b o o k f o r F i e l d E x c u r s i o n 0 2 ; I n t . G e o l . C o n g . , 2 4 t h , C a n a d a , 4 9 p p . F y l e s , J . G . , I 9 6 3 : S u r f i c i a l G e o l o g y o f H o m e L a k e and P a r k s -v i l l e M a p - A r e a s , V a n c o u v e r I s l a n d , B r i t i s h C o l u m b i a ; G e o l . S u r v . C a n . , Mem. 318 , 142pp . H a l s t e a d , E. C . , 1968 : The C o w i c h a n I ce T o n g u e , V a n c o u v e r I s l a n d ; C a n . J . E a r t h S c i . , V o l . 5, pp . 1 4 0 9 - 1 4 1 5 -J o h n s t o n , W. A . , 1 9 2 1 : S e d i m e n t a t i o n o f t h e F r a s e r R i v e r D e l t a ; G e o l . S u r v . C a n . , Mem. 12 5 , - 46pp. J o h n s t o n , W. A . , 1 923 : G e o l o g y o f F r a s e r R i v e r D e l t a M a p - A r e a ; G e o l . S u r v . C a n . , Mem. 135 , 8 7 p p -L e a r n i n g , S. F . , 1968 : Sand and G r a v e l i n t h e S t r a i t o f G e o r g i a A r e a ; G e o l . S u r v . C a n . , P a p . 6 6 - 6 0 , 149pp . 109. McKee, E. D. and W e i r , G. W., 1 9 5 3 : T e r m i n o l o g y f o r S t r a t i -f i c a t i o n and C r o s s - S t r a t i f i c a t i o n ; B u l l . G e o l . S o c . , Am. , V o l . Gk, pp . 3 8 1 - 3 9 0 . R o d d i c k , J . A . , 1 965 : V a n c o u v e r N o r t h , C o q u i t l a m , and P i t t Lake M a p - A r e a s , B r i t i s h C o l u m b i a ; G e o l . S u r v . C a n . , Mem. 3 3 5 , 2 7 6 p p . R o d d i c k , J . A. and A r m s t r o n g , J . E . , 1 956 : P i t t Lake ( V a n c o u v e r , E a s t H a l f ) Map, New W e s t m i n s t e r D i s t r i c t , B r i t i s h C o l u m b i a ; G e o l . S u r v . C a n . , 8 - 1 9 6 5 -R o d d i c k , J . A . , M u l l e r , J . E . , and O k u l i t c h , A. V. 1 9 7 3 : F r a s e r R i v e r ( 2215 ) Map S h e e t ; G e o l . S u r v . C a n . , Open F i l e Map No. 165 . Rowe, J . , 1 975 : The G e o l o g i c H i s t o r y o f Q u a t e r n a r y D e p o s i t s in the Mary H i l l G r a v e l P i t , P o r t C o q u i t l a m , B . C . ; u n p u b l . B .Sc . T h e s i s , U n i v . B r i t . C o l . , 6 7 p p . no. A P P E N D I C E S Number Laboratory on Maps Number 1 GSC 2177 2 GSC 2194 3 GSC 2203 4 GSC 2273 5 GSC 2277 6 GSC 2191 7 GSC 124 8 GSC 2217 9 GSC 2263 10 GSC 536 11 GSC 2107 12 GSC 2139 13 GSC 2140 14 GSC 2137 15 16 17 18 19 20 GSC 2167 GSC 2091 GSC 2094 GSC 2120 rerun of GSC 2091 GSC 2094-2 rerun of GSC 2094 QL-194* Date radiocarbon year before present 12,000±100 18,600±190 21,600±200 25,800±310 26,000+310 26,200±320 26,450±520 26,900+320 27,000±490 27,180+460 27,400+420 28,200+200 29,600±200 40,200+430 40,500±1700 >44,000 >44,000 >48,000 >49,000 >62,000 t levation (metres) Material Col lector 69 marine shel ls from Capilano J.E. Armstrong glaciomarine f ine sandy s i l t 61 wood from peat at base of J.E. Armstrong Quadra Sand 190 wood from fine sand in Quadra J.E. Armstrong Sand 50 wood from organic s i l t at top J.V. Matthews of Cowichan Head Formation 40 wood from sandy gravel in S.R. Hicock Cowichan Head Formation 40 wood from sandy gravel in S.R. Hicock Cowichan Head Formation-located 1 m from GSC 2277 35 peaty s i l t from s i l t y f ine sand J.E. Armstrong in Cowichan Head Formation 37 wood from sandy s i l t in S.R. Hicock Cowichan Head Formation 49 wood from peat in Cowichan S.R. Hicock Head Formation 35 wood from s i l t y clay in J.E. Armstrong Cowichan Head Formation 39 wood from peat in Cowichan J.E. Armstrong Head Formation 38 wood from peat in Cowichan J.E. Armstrong Head Formation 35 sapropel in Cowichan Head J.E. Armstrong Formation 34 wood from stony organic c o l l u - J.E. Armstrong vium, probably in Cowichan Head Formation 45 wood from stony organic c o l l u - S.R. Hicock vium, probably in Cowichan Head Formation 23 wood from stony laminated s i l t J.E. Armstrong in Semiahmoo? Dr i f t 114 wood from organic s i l t in High- J.E. Armstrong bury? Sediments 23 wood from stony laminated s i l t J.E. Armstrong in Semiahmoo? Dr i f t 114 wood from organic s i l t in High- J.E. Armstrong bury? Sediments 20 wood from stony laminated s i l t S.R. Hicock in Semiahmoo? Dr i f t *QL-194 was run by M. Stuiver, University of Washington. A l l other dates were run by the Geological Survey of Canada. A 2 9 »J 4 B 11 #13 12 122 °47' ? . m . 3 0 0 46'30' I 1 1 1 .ii—l | 122°47' ,y. M V i i 3 :i; I I) r \ -49°19' ' ' * -17 • v 19'. •] -18' .-.•./ i . - y (? 1 0 . 10,00 j)l22°46 >l I MARY HILL LOWER COQUITLAM RIVER VALLEY APPENDIX 1 : RADIOCARBON DATES 1 1 2 . Rock Types % Granit ic * and Locali t ies Associated* % Volcanic % Quartzite, % Quartz % Other* X Garibaldi Chert, Pe-type l i t e , Argi l -1 l i t e Total Tott l % Derived % Dervied from from Coast Mtns. Cascade Mtns. Mary H i l l ; estimated rat io Coast/Cascade provenance: Capilano Suprali 1 ttoral lag. gravel: 92 4 - 4 -2 93 5 - 2 -3 91 3 2 3 3 Capilano Glaciomarine: 4 82 8 - 8 1 1 Vashon T i l l : 5 85 8 - 7 - -6 79 11 - 7 - 3 7 83 6 3 9 2 Vashon Outwash: 8 78 7 - 11 2 2 9 80 6 - 11 2 1 10 80 8 - 11 1 -11 89 2 1 7 " 2 Quadra Sand: 12 80 6 - 6 6 2 13 83 5 - 7 Z 3 14 77 6 - 13 3 1 15 77 8 - 9 2 4 16 87 8 - 3 1 1 17 78 7 - 12 3 18 80 5 - 11 2 2 Coquitlam Dr i f t 19 47 10 - 38 4 1 20 63 14 - 20 3 21 89 9 - 2 " Cowichan Head Formation: 22 92 5 - 1 - 2 23 92 3 - 3 2 24 95 4 - - 1 25 91 5 - 3 1 Semiahmoo?Drift 26 88 3 - 4 5 27 86 6 - 4 1 3 28 93 5 - - - 2 29 92 6 - 2 - -30 86 5 - 5 2 2 31 86 7 - 7 -32 82 7 2 9 1 1 Lower Coquitlam River Val ley; estimated rat io Coast/Cascade provenance 19:1 1:9 0 1:1 2:3 Capilano Supral ttoral 33 95 2 1 1 2 Capilano deltaic sand and gravel: 34 93 5 1 2 -35 89 4 - 3 2 Vashon T i l l : 36 91 3 2 4 1 1 37 98 1 1 38 92 4 1 2 2 39 95 3 - 1 1 Vashon Outwash: 40 87 5 - 8 41 91 4 2 z 1 42 94 3 - 2 1 -43 96 2 2 1 1 Quadra Sand: 44 88 5 - 5 i 1 45 89 4 - 5 Semiahmoo? Dr i f t : 46 86 7 - 5 I 1 47 97 2 - 1 48 92 5 2 2 - 1 49 94 5 - 1 • Highbury? Sediments 50 92 4 - 4 51 90 5 - 4 - 1 Westlynn D r i f t ' 52 98 1 - - 1 53 93 ' 3 ' - 2 54 95 2 - 1 1 55 99 . 1 1 " -Port Moody; estimated rat io Coast/Cascade provence: 9:1 1:4 0 1: Vashon?Till: 55 94 3 - 2 -Semiahmoo?Ori f t: 58 59 90 93 89 90 93 90 91 * Granit ic and associated rock types include raigmatites, metasedimentary, metavolcanic, amphibolites, and greenstones :'.-?3 ••10 13 • 4 9 V 6 . 1 \ f i 30 1 I 1 ^V -• 2 3 21 . .5 29 27. MARY HILL LOWER COQUITLAM RIVER VALLEY -25" • r-20" 56 59 . 58 49V15" . .g 7 [SO ? " 1°(>122O52l40"' Others includes Tertiary rock types and ^lder sedimentary rocks. PORT MOODY APPENDIX 2:PEBBLE PROVENANCE ANALYSES AND LOCALITIES GLACIAL DIAMICTON PEBBLE FABRICS* (based on samples of 25 pebbles) Analysis Plunge Direct ion of Amount of Fab r i c * * No. Preferred Pebble Long Axis Plunge Strength VASHON TILL: 1 015° 13° Strong 2 196 05 Weak 3 069 50 Strong 4 035 14 Strong 5 - - None 6 186 07 Weak 7 - - None 8 186 15 Weak 9 051 09 Weak 10 166 05 Weak 11 - - None 12 034 07 Weak 13 180 01 Strong 14 198 01 Strong 15 168 05 Weak 16 178 15 Strong COQUITLAM GLACIOMARINE? 17 053 18 180 19 SEMIAHMOO? TILL: 20 215 21 22 060 23 319 24 019 25 175 SEMIAHMOO? GLACIOMARINE?: 26 27 28 200 CAPILANO GLACIOMARINE: 29 02 07 09 12 45 03 14 25 Strong Strong None Strong None Weak Strong Weak Strong None None Strong None Data was taken from a computer analys is of the w r i t e r ' s f i e l d measurements done by D.M. Mark, Geography Department, Simon Fraser Un iver s i ty . Data for #27 was taken from Rowe, 1975. * Fabric Strength i s based on Mark's s t a t i s t i c a l i n terpretat ion of the data at the 95% confidence level. •••Mi . . . •49°U MARY HILL LOWER COQUITLAM RIVER VALLEY r •23 . . •. r49pi7,o'.*--i.Q * IQ0122o52'40" PORT MOODY DISPOSAL SITE Preferred fabric orientation; lack, of t i c k s i n -dicates the fa b r i c i s random. •Stereograms are equal-area lower hemisphere projections of pebble long axes. Ratio of long/intermediate axis • lengths ranged from 1.5 to 2.0 APPENDI X 3 •' S T E R E O G R A M S * AND LOCALITIES OF GLACIAL DIAMICTON PEBBLE FABRIC ANALYSES 114. Li thostratigraphi c Unit Pit A (Mary H i l l ) : MH01SD MH02GV MH03SD MH04PT MH05PT MH06SD MH07GV MH08ST MH09ST HH10ST HHUTL MH12ST MH13PT NH14PT MH15GV MH16SD MH17SD MH18GV MH19SD MH20SD MH22GV MH23GV MH24SD MH25SD MH26GV MH27SD MH28SD MH28aGM MH29SD MH30GM MH31ST MH32SD MH33SD MH34GM HH35SD HH36GM MH37GV MH38TL MH39SD MH40SD MH41GV MH42GV M.H43TL HH44GV HH45TL MH46SD MH47SD HH48SD MH49TL MH50GV MH51SD HH52GM MH53GV MH54TL MH55ST MH56GH MH57SO MH58SD MH59TL MH60ST MH61SD MH62TL MH63GV MH64TL MH65GV Cowichan Head Formation Cowichan Head Formation Cowichan Head Formation Cowichan Head Formation? Cowichan Head Formation? Cowichan Head Formation Cowichan Head Formation? Semiahmoo? g lac io lacustr ine Cowichan Head Formation? Semiahmoo? g lac io lacustr ine Semiahmoo? lodgement t i l l Semiahmoo? g lac io lacustr ine Cowichan Head Formation Cowichan Head Formation Cowichan Head Formation Cowichan Head Formation Cowichan Head Formation Cowichan Head Formation? Cowichan Head Formation? Cowichan Head Formation Cowichan Head Formation Cowichan Head Formation Cowichan Head Formation Quadra Quadra Quadra Quadra Coqui tlam Dri f t Cowichan Head Formation Co'quitlam Dr i f t Cowichan Head Formation Cowichan Head Formation Cowichan Head Formation or Quadra-below Coquiltam D r i f t Coquitlam Dr i f t Cowichan Head Formation or Quadra-below Coquitlam Dr i f t Coqui1 tarn Dri f t Cowichan Head Formation or Quadra-below Coquitlam Dr i f t Vashon lodgement t i 11 Quadra Quadra Vashon outwash Vashon outwash Vashon lodgement ti11 Vashon outwash Vashon lodgement t i l l Quadra Quadra Vashon outwash Vashon lodgement t i l l Capilano supra l i t tora l Quadra Semiahmoo? glaciomarine? Semiahmoo? outwash Vashon lodgement t i l l Semiahmoo? g lac io lacustr ine Semishmoo? glaciomarine? Quadra Semiahmoo? g lac io lacustr ine? Semiahmoo? lodgement t i l l Semiahmoo? g lac io lacustr ine Quadra Vashon lodgement t i l 1 Vashon outwash Vashon lodgement t i l 1 Capilano supra l i t to ra l Sand S i l t Gravel MH66GV Vashon outwash MH67GV Capilano supra l i t to ra l MH68GV Cowichan Head Formation P i t B (G.V.S. 5 D.D., or West-Lin WL01SD Capilano raised de l ta i c Pit C (All ALO.ST AL02GV AL03SD AL04ST AL05ST AL06SD AL07GV AL08TL AL09SD AL10ST ard): Capilano glaciomarine Vashon outwash Capilano raised l i t t o r a l Capilano glaciomarine Capilano glaciomarine Capilano raised de l ta ic Capilano supra l i t to ra l Vashon lodgement t i l l Vashon outwash Vashon g lac io lacustr ine? Pit D (Kask Bros.): KB01SD KB02GV KB03TL KB04ST KB05GV KB06SD Capilano raised de l ta ic Capilano raised de l ta i c Vashon lodgement t i l l Vashon g lac io lacustr ine Vashon outwash Quadra Pit E (Johnson): JN01GV JN02GV JN03ST Jri04SD JN05TL JN06SD 0M07GV JN08SD JN09SD JfJIOSD JN11ST Pit F (S SS01GV SS02SD SS03GV SS04TL SS05TL SS06SD SS07GM SS08GV SS09SD SS10TL SSI 1 SD SS12TL Vashon flow t i l l ? Vashon outwash Vashon g lac io lacustr ine Vashon g lac io lacustr ine? Vashon lodgement t i l l Quadra Westlynn? outwash? Vashon outwash Westlynn? outwash? Vashon outwash? Vashon g lac io lacustr ine? and S): Westlynn? outwash? Highbury? f l u v i a l Highbury? f l uv i a l Semiahmoo? lodgement t i l l Semiahmoo? lodgement t i l l Semiahmoo? outwash Semiahmoo? glaciomarine? Semiahmoo? outwash Quadra Vashon flow? t i l l 'Vashon g lac io lacustr ine? Vashon lodgement t i l l P it G (Cewe): not sampled Pit H (Port Moody): PM01SD Semiahmoo? proglacial PM02TL Vashon lodgement t i l l PM03SD Semiahmoo? proglacial PM04SD quadra PM05SD Semiahmoo? proglacial PM06TL Semiahmoo? lodgement t i l l PM07SD Cowichan Head Formation? PM08SD Cowichan Head Formation? PM09ST Cowichan Head Formation':' PM10SD Quadra PM11SD Quadra PM12ST Semiahmoo? g lac io lacustr ine? T i l l Glaciomarine? Peat or organic co l luv iu .•50 -49» .64'. 65 66 48 •49V 62. 51. 56 57. 41 46 •• 38 * 4714'. 89 „ 17 36» 11 8 28o 37 6 0» 12 i g ;.18 » 3 1 i 13 % 29 •f 23 22 30 • * 43 24 5 6 61 59' 25 ?c ••to* 68 3 : > --•44 ?45 *67 43 PIT A PITS B to G P I T H APPENDIX 4: SEDIMENT SAMPLE LOCALITIES F I G U R E 3 DIAGRAMMATIC CROSS SECTIONS MARY HILL GRAVEL PIT PORT COQUITLAM, B. C. 400 m 400 m L E G E N D a SUPRAL]TTORAL LAG GRAVEL Very poorly sorted, conronly contains sandy to s l l ty matrix; marine shel 1 casts found In places. GLACIOMARINE STONY CLAYEY SILT , , Blocky structure, manganese oxide stalninq on joint surfaces; contains fossi l marine shells and shell fragments. , , L l Platy and well compacted in places. Includes some laminated stony s i l t (ponded) and openwork qravel lenses; boulders up to R n d1a. observed: probably mainly lodgement but may In part be flow t i l l »tiere massive or contorted and poorly compacted between t i l l layers In places; probably proximal outwash. Faulted, contorted, cross-bedded, and contains gravel lenses and interbeds In upper part of unit; well sorted, subhori/ontally thinly bedded and tross-bedded; contains detrital coal and peat clasts, scattered stones and stone clusters; probably pronlaclal (distal) outwash. SIONV CLAYEY SILT Massive, generally poorly comoacted contains fossi l marine shells and shell fragments; probably glaciomarine but may in part be t i l l . SANDY GRAVEL Fe-stalned, moderately sorted; m some exposures grades down wards Into very thinly bedded, sand at the base of the unit; contains scattered coal. wood, and peat clasts, and one or mor dia. and t m long; probably fluvial and qlaciofluvlal deposits; wood dates range from 25.800 rross-bedded. and rippled fine -.and and s l l t y fine I thin peaiy wood layers with fossi l logs up to 30 cm to ?n.0O0 yr. R.P. FOSSIL BOG AND GYTTJA DEPOSITS Tninly interbedded peat, sapropel. and well sorted fine sand layers; peat layers contain fosstl tree stumps up to 30 cm dia . roots, and logs up to 3 m long; sand layers contain finely disseminated organic material and fossil Insects; sapropel Is diatomaceous; probably fluvial and lacustrine deposits; dated peat and sapropel layers range from ?7,000 to 29.600 yr. R.P. S ,^'\wo Lcru*iy°?nwrbedde ,d l"phases: a dense, stony and gr i t ty. drtrlBl organic-rich phase containing fossi l wood, leaves, and Insects (weathered surface resembles t i l l ) ; and a contorted, stony, wood-bearing s i l t - r i c h phase containing clasts of laminated stony s i l t , and gravel and sand lenses; whole complex thought to represent reworked orgainc and glacial sediments by mass wasting processes a piece of wood from the detrital organic-rich pnase dated 40.J0O • ««3 yr. B.P 40,i0u - 1700 yr. B.P. root from the contorted UNDIFFERENTIATED GLACIAL COMPLEX Includes lodgement t i l l , massive stony clayey s i l t (weathers to blocky structure), rhythmically laminated s i l t and fine sand containing scattered stones, gravel and sand; missive stony clayey s i l t probably glaciomarine. laminated s i l t and fine sand orobably glaclolacustrine. and gravel and sand probably outwash; wood from laminated s i l t was dated as >62,000 yr. B.P. MM* Major Unconformity; observed, inferred Ideological Contact; observed. Inferred Reconstructed Kary H i l l pro f l i t • Topographic profile at time of rapping Area of measured section Bedding thicknesses classif ied accordlno to "cKee and M e l r . I N D E X M A P 

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