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Palynostratigraphic investigation of upper maastrichtlan and paleocene strata near Tate Lake, N.W.T. 1973

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PALYNOSTRATIGRAPHIC INVESTIGATION OF UPPER MAASTRICHTIAN AND PALEOCENE STRATA NEAR TATE LAKE, N.W.T.. by \ Gerhard Bihl B.Sc, University of Alberta, 1967 M.Sc, University of Alberta, 1968 . A thesis submitted in p a r t i a l fulfilment of the requirements for the degree of doctor of philosophy i n the Department of • Geology V/e accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA October » 1973 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make i t freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the Head of my Department or by his representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of The University of British Columbia Vancouver 8, Canada * 1 ABSTRACT Sedimentary strata near Tate Lake, south of Norman Wells, N.W.T., were investigated using palynomorph analysis indicating the presence of Upper Maastrichtian and Paleocene beds. The Upper Maastrichtian sections contain tv/o local palynostratigraphic zones correlative with Srivastava's Wodehousea spinata and Manci- corpus gibbus zones of the Edmonton and Battle Formations of Al- berta, and other Maastrichtian formations in western North America. The Paleocene strata compare lit h o l o g i c a l l y and palynologically with the Lower Fort Union Group of Montana and Wyoming, the post- Brazeau beds of the Alberta Foothills, the upper part of the Bonnet Plume Formation, N.W.T., and Tertiary coal deposits in Spitzbergen. A progressive cooling in climate from subtropical to warm temperate during Upper Maastrichtian times is indicated by the decrease in the number of angiosperm species and greater influx of gymnosperms and pteridophytes, A marked change in microflora and lithology at the Cretaceous-Tertiary boundary indicates tempe- rate conditions and increased rates of sedimentation in the Tate Lake area. Major lignite seams characteristic of the Paleocene strata probably were produced in freshwater swamps in one of the subsiding sedimentary basins formed along the east side of the Mackenzie Mountains during the Laramide orogeny. The Tate Lake strata appear to be part of the Hell Creek-Fort Union type formational se- quences straddling the Cretaceous-Tertiary boundary indicating that climatic and sedimentary conditions were very similar a l l along the Rocky Mountains. On this basis corresponding changes are predicted for the Monster, Reindeer and Moose Channel Formations. TABLE OF CONTENTS Abstract Table of Contents List of Text Figures List of Microfossil Figures Acknowledgements Introduction Purpose of the study Previous work done Present f i e l d and laboratory work Stratigraphy Results Assemblages and zonation Reworked palynoassenblages Correlation Paleoecology Absolute age of the Tate Lake lignites Summary and Conclusions References i i i PAGE Appendix I 38 Appendix II 4-3 Microfossil Figures 47 iv- TEXT FIGURES TEXT FIGURES ' PAGE 1, Map of Tate Lake area 3 2a. Badlands developed in Lower Paleocene sediments near Tate Lake, N.W.T 4 2b. Volcanic ash marker in Lower Paleocene beds of the Tate Lake Formation 4 3o Tate Lake Formation type section..................... 8 4 . Tate Lake composite section...... 9 5. Correlation chart of Upper Cretaceous and Lower Tertiary formations along the east flank of the Rocky Mountains . 17 6. Schematic temperature curve of the early Tertiary for western U.S.A. and Colombia, S. America.,.....,. 23 7. Schematic diagram of climatic and f l o r a l changes in Central Europe during the early Tertiary...... '. 23 8 . Relationship•between plant growth, decomposition, and rate of plant debris accumulation...,.,,..,...,. 25 9. Present day distribution of peat bogs................ 25 MICROFOSSIL FIGURES Figures 1 - 12 13 - ,24 26 - 43 44 -62 63 - 78 Facing Page 47 48 49 50 51 v i > ACKNOWLEDGEMENTS I am most grateful to Dr. G.E. Rouse, under whose direction this thesis was prepared, and who gave generously of his time for discussions, provided continual encouragement and proved an ever-present source of stimulation. I also wish to extend my my assistant Mr. Ross H i l l for help in the f i e l d beyond the c a l l of dutyj Dr. F.R. Clarke, P.Gordy, C.Bruce and A.Audretsch of Shell Exploration, Calgary, for organizational support before and during the fieldwork; Drs. C. Yorath and W. Brideaux from the Geological Survey of Canada and Mr. D, Mclntyre, Chevron Standard, Calgary, for helpful discussions. Support for the thesis work was provided by National Research Council and Union Oil Company grants plus Shell Exploration f i e l d and laboratory assistance. Dr. L. Bayrock and Mr. T. Reimchen assisted e d i t o r i a l l y . 1 INTRODUCTION The purpose of the present study i s a palynostratigraphic zonation of a series of interbedded l i g n i t e s , shale:;s, siltstones, sandstones and chert conglomerates exposed in badlands west of Tate Lake near the headwaters of the East Fork of L i t t l e Bear River (Fig,1,2) and to compare the obtained palynomorph assemblages with those of similar age from other regions of western North America, The resultant biostratigraphic framework should assist o i l exploration efforts being conducted in the Mackenzie lowlands. The badlands appear to be part of a series of erosional Tertiary remnants that extend a.long the eastern flank of the Rockie Mountains from Wyoming to the Mackenzie Delta. Except for a wind- swept treeless dissected platea.u at elevations between 800 to 1000 meters above sea l e v e l , the area i s covered by dense taiga and muskeg, v/ith many lakes poorly drained by small meandering streams. Outcrops between altitudes of 800 to about 600 meters occur only as mudslide scars and cutbanks along the major streams. In 1768 Alexander Mackenzie observed, burning coal seams along the Mackenzie River near Fort Norman, which are very similar to the coal seams exposed in the Tate Lake badlands. J.W. Dawson (I889) correlated plant macrofossils collected from the banks of the Mackenzie south-west of Fort Norman with the Fort Union f l o r a of the Great Plains, and Williams (1922) described in det a i l the lithologies from which the f o s s i l s v/ere collected. Bell (19^9) identified the flora as correlative v/ith the post-Brazeau beds of the Coalspur Saunders area, Albsrta, assigning to i t a Lower Paleocene age. No work was carried out in the Tate Lake area 2 u n t i l the Second'World War (the Canol project), during which Hart ( 1 9 ^ 4 ) , probably on sediraentologic and stratigraphic evidence assigned the .lignites and conglomerates of the badlands to the Tertiary, describing them as resting .conformably upon the Upper Cretaceous East Fork Formation. To obtain palynologic evidence of the age of the Tate Lake deposits, several sections in the badlands were measured and sampled by the writer to ensure as much horizontal and verti c a l coverage as possible ( F i g .3 , 4 ) . Nearly a l l shales, siltstones and lignites were sampled to obtain maximum information on the sedimentation and contemporaneous paleoecological conditions. Badland exposures on the east side of. Summit Lake were also in- ; vestigated, a.nd descending the East Fork of L i t t l e Bear River by rubber raft more information about the stratigraphic relation- ships between the Tate Lake beds and underlying strata was obtained. Standard palynological techniques using HF, HNQ^, and KgCO^ were employed to prepare the organic residue from the rock matrices; the mounting medium is glycerin j e l l y . Photomicrographs v/ere obtained with a Leitz Orthomat on Leitz Ortholux microscope # 634136 . 3 F i g . l - M a p of Tate Lake a r e a . Let ters A - E denote c r o s s - h a t c h e d a r e a . T denotes p r o b a b l e extent of sections in the Tertiary strata. 4f Fig. 2a. Badlands developed in Lower Paleocene sediments near Tate Lake, N.W.T.. View from the B-section due east towards the A-section indicated by an arrow. Fig. 2b. Volcanic ash marker surrounding charred tree ( ? Metasequoia ) above a massive lignite seam, B-section. The measuring stick to the right of the tree stump i s 5 feet long. 4 Fig- 2 b 5 STRATIGRAPHY Two distinct l i t h o l o g i c a l units were recognized in the Tate Lake badlands. The lower unit consists of soft grey and brown shales with minor beds of fine grained sandstone. The upper unit is characterized, by thick conglomerates and series of closely spaced lignites interbedded with siltstones, shales, many volcanic ash layers and minor sandstones. From the contact with the upper unit at the headwaters of the East Fork River, no major lithologi c a l changes were recognized by the writer when descending the the junction with the L i t t l e Bear River. Near this junction (N 64°47'; W 126°02') is the type section of the East Fork Formation currently being redefined by Dr. C. Yorath of the Geological Survey (pers.comm.) which is Late Campanian to Early Maastrichtian in age. Since there appears to be a uniform lithology between the type section and the contact with the overlying conglomerates at the headwaters of the East Fork River the lower unit is here tentatively referred to the East Fork Formation. Palynoassemblages recovered reach from Upper Cam- panian-Lower Maastrichtian to Upper Maastrichtian which makes the East Fork Formation correlative with the Edmonton Formation. If sedimentation throughout the Maastrichtian was continuous in this area palynostratigraphic zones similar to those described by Srivastavafrom Alberta can be expected. 6 The upper unit is described in Hume (1954): "On the L i t t l e Bear River and tributaries, Hart (10) reports 1,600 feet (484.8 meters) of Tertiary beds. These consist of coarse, carbonaceous sands, gravels, conglomer- a t e s , shales, and lig n i t e s . At the headwaters of the East Fork River there are lignites 8 to 10 feet thick. For 18 miles along the East Fork River, near i t s headwaters, the high h i l l s on both sides are made up of Tertiary beds with a measured thickness of over 1,200 feet (363.6 meters)". This entire unit is characterized by rapid lateral change in lithofacies. For purposes of correlation with time equivalent rock units in the N.W.T. and adjacent area's of western North America the approximately 400 meters of Tertiary strata covering close to 1200 spuare kilometers are here informally designated the Tate Lake conglomerates. The Tate Lake conglomerates extend from near Red Dog Mountain on the Keefce River in the south (N 64°l5'j W 125°30') along the upper Summit Creek to the vincinity of the junction of Ration Creek and the L i t t l e Bear River (N 64°35'; W 126°10'). Eastward the Tate Lake conglomerates can be traced to the head- waters of the East Fork River and Tate Lake (approx. N 64°35'» W 125°10') and from there south along Steward Lake to the Keele River. The Tate Lake conglomerates may be continuous v/ith the Tertiary strata on both sides of MacKay Mountains and around Fort Norrnan from where they extend about 50 kilometers up the Big Bear River to the Franklin Range and up the Mackenzie River beyond old Fort Point (Williams 1922, Hart 1944, Hume 1954, Yorath pers. comm.). Good outcrops occur around Tate Lake, Summit Lake and the MacKay Mountains. However most of the surface overlying the Tate Lake conglomerates is muskeg and exact boundary relationships are un- certain. In general the Tertiary strata are bounded by Cretaceous 7 rocks to the north and south, and by Devonian rocks to the east and west. Where observed the Tate Lake conglomerates overlie con- formably the East Fork Format ion (Hart 1944, Bihl this reoort) and are overlain by glacial d r i f t (Tassonyi 1969). The sampled sections are located at the headwaters of the East Fork River, in a treeless badland terrain between about 6?0 and 1170 meters above sea level (Fig. l ) . The general lithology (Fig. 3 and 4) from the contact with the East Fork Formation is approximately 33 meters of rusty weathering conglomerates with sand and coal stringers and one major coal seam near the bottom; this is followed by 177 meters of grey weathering chert conglomerate v/ith sand, siltstone and shale stringers; then 126 meters of interbedded l i g - nites (seams up to 2.6 meters thick), shales, siltstones and nume- rous volcanic ash beds of which very few exceed JO centimeters; and on the top there are about 40 meters of chert conglomerate and conglomeratic sandstones with minor shales and occasional coal stringers. As a result of local lignite combustion the surrounding shales and siltstones are baked a brick red and associated vol- canic ash layers are fused to a grey or jasper coloured "glass" occasionally f i l l e d , with leaf impressions of Metasequoia occi- dentalis (Rouse pers. comm.). 0 0 OO -J 3- o O Oo o O o O O 7ZZZZZ 10.1 I 12 — 1 i 20 o o o o 2 4 , zzzzzzz V7777) 26 • 2 I 2 2 - I 2 1 1 - 1? _ 7 - 6 O . o-o' • 0 . •°o '. • o 0" 00 • 0 •» 0", TJLZJJLl o :o B <~ \4-. o<> o 0 O 0 „ ZZZ2Z 225 o ° Oo 8 }• 7 sr t f l • 5 • p a I y n o Io g i c a I s a m p l e n u m b e r s a r e r e f e r r e d to in t h e t e x t . v o l c a n i c a s h 5 6 x 1 0 y e a r s V E R T I C A L S C A L E ir 0 20 o o S I L T S T O N E S A N D S T O N E C O N G L O M E R A T E r v W l M V O L C A N I C A S H F i g . 3 L a t e r a l l y r e l a t e d s e c t i o n s of P a l e o c e n e s t r a t a n e a r To te Lak< •nil: 0 ° 0 o ° O . 0 o H I . ; S ! . ; ' i . § 0= 7 1# I X I o n I y raworked A l B I A N a n d M I S S ISS I PP I A N O l l t m b l o g l l . p f « i • n t in thole I t n i t i L E G E N D : X * X W r i w o r V o d c o m m o n — — r o r » • T . l . M I 8 T A T E I A K E C O M P O S I T E S E C T I O N W I T H t O C A L S T R A T I G R A P H t C R A N G E S OF C H A R A C T E R I S T I C I N D E X P A l Y N O M O R P H S . S c a t * t S T R A H O R A P H I C O C C U R R E N C E A q w i l o p o l l e n i t a t trio la tv* Manclcorput t « n o n i c u m A q . r a d v c l u i group R o u i « o rubt i t i i l i burn i ipor i t e i ddnocut Proteocidifct ongulo tut C r a n w i l I t o • I ti o to Mane icor put g ibbut M . ro t l ra lut P u l c K « r i p o l l « n i f « t k r c m p l i l o r a n t h a c i t « i p i l a t u i C r o n w a l l i a cf r u m t * f * n t i t Son t o l u m i d i l e l tp . A q . ( o n o l u i A q , d i tpot i tut P r o t « o c i d i t « t occal fo tut S c o l t a r d i o n o r m a n c n t i i W o d e h o u t e o sp ina to T o u r o c u t p o r i t « i » p . V o r i r u g o t i i p o r i f t l « p . Bacu Io t i i por i t « s i lv i i formtt Tiggapof t e n i t « i i p . Sequoia pof len i f • • p g l « a t « n i c o i In ta topar lurop . cf. moo, AUS M y r i c a c s a e - complex Poro ln ipo l l en i te t i p . A q . dol ium A q . odamas Fro x i no i p . va r i ab i l i s Tr ico lp i fe t hiont T. o n g u l o l u m i n o i w t T y p h o c e o * - Er i coceao A I n u t t p . 10 RESULTS For correlation purposes a composite section was compiled to encompass both the Paleocene and Maastrichtian beds (Fig.4), The Paleocene sediments, dominated by poorly sorted coarse elastics, showed good recovery of palynomorphs from siltstones and shales interbedded with the l i g n i t e s . The lignites themselves are generally very woody with low palynomorph content. Shale stringers in the conglomerates usually yielded a high proportion of Lower Cretaceous and Mississippian palynomorphs. The best recovery from the underlying Maastrichtian beds v/as obtained from dark grey shales. Assemblages and Zonationi Analyses of samples show three well-defined palynomorph assemblage zones present in the composite Tate Lake section. The characteristic index species only are listed here. Complete listings of palynomorphs for the three assemblage zones are given in Appendix I I . The zones denoted T.L.I and T.L.II are Maastrichtian in age while T.L.III i s of Paleocene age. The lowest zone (T.L.I) shows the greatest species diversity and i s characterized by the following (see Plate I): Mancicorpus gibbus Srivastava M, rostratus Srivastava 5!» pulcher (Funkhouser) Srivastava Aquilapollenites reductus Norton A, reticulatus Norton 11- Proteacidites angulatus Samoilovitch P. crispus Samoilovitch P. cf thalmannii Anderson Callistopollenites radiostriatus Mtchedlishvili Rousea subtilis Srivastava Libumisporites adnacus Srivastava This zone strongly resembles the Maneicorpus gibbus subzone of the Scollardia trapaformis zone of the Edmonton Formation and Battle Formation of Alberta (Srivastava 1970). The middle zone (T.L.II) i s the equivalent of the Wodehousea spinata zone of the Edmonton Formation (Srivastava 1970)» with the following characteristic palynomorphs (see Plate II & III)1 Wodehousea spinata Stanley Aquilapollenites conatus Norton A. dispositus Mtchedlishvili Scollardia normanensis n.sp. Cranwellia cf C. rumseyensis Srivastava Proteacidites occalatus Samoilovitch Pulcheripollenite s krempii Srivastava Loranthacites cf L_. ' pilatus Mtchedlishvili Santalumidites sp. The upper zone (T.L.III) i s Paleocene in age, generally correlative with early Tertiary palynomorph assemblages from the Great Plains, Spitzbergen and Siberia.There appear to be two sub-assemblages in this zone. The following are characteris- t i c and/or dominant of the lower part of zone T.L.IIIi 12 a/ Lower sub-assemblage J Interaperturopollenites c.f I_. magnus (Potonie) Thomson••>.& Pflug Sequoiapollenites paleocenicus Stanley cf Metasequoia occidentalis Tsugaepollenites sp. Triporopoll.enites mullensis (Simpson) Rouse & Srivastava Myricipites dubius Wodehouse Baculatisporites comauensis (Cookson) Potonie B, ilexiformis n.sp. Taurocusporites segmentatus Stover . Varirugosisporites cf _V. tolmanensis Srivastava Palynomorphs that are common or restricted to the upper part of zone T.L.III are« . b/ Upper sub-assemblagei Fraxinoipollenites v a r i a b i l i s Stanley Tricolpites hians Stanley _T. l i l l e i Couper T. anguloluminosus Anderson Aquillapolenites dolium (Samoilovitch) Srivastava A, adamas n.sp. Cap r i f o l i i p i t e s sp. Alnipollenites sp, Betulaceoipollenites infrequens (Stanley) Rouse & Srivastava Taxodiaceaepollenites hiatus.- cf Glyptostrobus sp. Piceapollenites sp. Pinuspollenites sp. 13 Reworked Palynoassemblages: Perhaps the greatest source of error in palynostratigraphical work i s introduced by the rev/orking of older microfloras. In a rapidly shi f t i n g sedimentary environ- ment this may even lead to.the mixing of contemporaneous floras and obliterate facies differences. Stanley '(19^9) states that "These secondary grains usually are present in larger number in both marine and non-marine sediments than most workers would like to admit. Any attempt at climatic interpretation necessitates subtraction of the reworked grains in order to reach accurate conclusions." Palynomorphs of Mississippian, Permian and Albian age were noted throughout the composite Tate Lake section (Plate V), The follow- ing i s a l i s t of samples showing the type of mixed assemblages; the letter-numeral designates refer to sections and samples as shown in Figure 3 purely Mississippian-Albian assemblages} A19;B12,14;C2,3,11;D23 •mixed Miss.-Alb. & Paleocene' " J B1,11;C5,6,9;D17-20 mixed Maastricht & Paleocene "• i A10;B9 ,11;C13 , l6;Dl4 purely Paleocene ass. i A3-5»13i15-17iB3,10,13;C?jDIO,11,24,25. The pureD.y Mississippian-Albian assemblage was also encoun- tered in Albian rocks by Rouse (pers. comm.) in the Peel River area, Audretsch (pers, comm.) in the Mt. Goodenough section of the Richardson Mounta ins, and by the writer in oilwell cuttings from the Eagle Plains and the Mackenzie Delta. It is quite possible that u p l i f t and erosion during Albian times produced the mixture of mainly lower Mississippian spores and Middle Albian dino- flageHates. These were then reworked together in Maastrichtian and Paleocene times. This interpretation appears more l i k e l y than deriving Mississippian and Albian palynomorphs from separate 14 outcrops, because of the areal extent of the mixing throughout the lower Mackenzie valley and eastern Yukon. An 83 meter interval of conglomerates and sandstones in the lower C-section contained some shale lenses yielding only Mississippian-Albian assemblages (Fig. 4 ) . Similar assemblages were also recovered from the extensive outcrop of rusty and crossbedded white sandstone on the east side of Summit Lake, which is barren except for a few stringers of coaly shale no more than 1 to 5 centimeters thick (showing up as moist springlines on the h i l l s i d e s ) . From their stratigraphic position and litholog i c a l appearance these sandstones are most li k e l y Ter-' tiary (Hart 1944, Hume 1954, Yorath 1 9 ? 0 ) . Reworked Maastrichtian palynomorphs affects the dating of rock units based on index markers e.g. based on their occurrence in the Tate Lake conglomerate, the ranges of the Maastrichtian Wodehousea spinata, Maneicorpus rostratus, M. senonicum, Aquilapollenites dis- positus, A_. reticulatus and Cranwellia striata would extend into the Paleocene. The rare occurrence of the mainly Santonian-Campan- ian JL_. trialatus in both Upper Maastrichtian and Lower Paleocene sediments seems to indicate that the above species is reworked in the Tate Lake conglomerates rather than part of the contemporan- eous Paleocene microflora. State of preservation is usually not a good, criterion in the interpretation since many samples in the Tate Lake conglomerates yielded also poorly preserved Paleocene palyno- morphs. However the reworked specimens of V/odehousea spinata can be quite clearly distinguished from the excellently preserved and abundant specimens of T.L.II zone in the Upper East Fork Formation. 15 Only the smaller Maastrichtian species of Aquilapollenites are well preserved in the Tate Lake conglomerates. Aquilapollenites dolium and A., adamas v/ere found in excellent condition and are probably part of the contemporaneous Paleocene microflora. Taurocusporites sp. considered by Eliuk (1969) to be a contami- nant in his Lower Paleocene assemblage is herein considered to be a Paleocene contemporary on the basis of consistent occurrence and good preservation in a l l four sections of the Tate Lake l o c a l i t y . Taurocusporites segmentatus ranges together with Baculatisporites comauensis, Varirugosisporites cf. V_. tomanensis, Erd tmanipollis procumbentiformis and other forms from the Maastrichtian into the Paleocene. As more data become available i t w i l l be possible to eliminate reworked species on a s t a t i s t i c a l basis as well as to extend the ranges of species that do carry on into the Tertiary. The fact that most thick conglomerates and sandstones with thin shale stringers in the Tate Lake sections contained a very high percentage of reworked palynomorphs, while thick siltstones and shales contained only a small percentage, might be worthwhile to investigate in neighbouring areas. If the relationship between percentage of reworked palynomorphs and coarseness of sediment can be : proven"consistent in other areas of the N.W.T. e.g. the Mackenzie Delta, then the percentage of reworked microflora might be useful in the interpretation of interrelationships of subsurface strata penetrated by oilwells to complete the data in- ferred from well-logs. 16 PALYNOSTRATIGRAPHIC CORRELATION Of the three local assemblage zones established in the study- area the lowest one T.L.I (Fig. 4) is correlative with the Manci- corpus gibbus subzone of the Scollardia trapaformis zone established by Srivastava (1968, 1970) in the Red Deer and Cypress H i l l s areas of Alberta. Srivastava's argument that this assemblage zone is of stratigraphic significance is supported by the 1500 kilometer dis- tance separating Tate Lake and the Red Deer Valley. The T.L.I is also characterized by the presence of Maneicorpus rostratus and the abundant occurrence of small reticulate aquiloid grains e.g. Aquilapollenites reductus, and Liburnisporites adnacus. The latter has been described by Srivastava (197?) but i t s stratigraphic ' '• occurrence within the Edmonton Formation is not specified. Another palynomorph assemblage that appears to be correlative with the M. gibbus subzone and T.L.I is the one described by Eliuk (1969) from Hardisty Creek, western Alberta. Eliuk features Protepidites thalmannii which is rare in the T.L.I. In comparison with the good yields and excellent preservation obtained by Srivastava (1968) both the Hardisty Creek and Tate Lake l o c a l i t i e s yielded smaller numbers of formspecies and a somewhat poorer preservation which may be indicative of higher energy sedimentary environment closer to the Rocky mountains. Local assemblage zone T.L.II, characterized by Wodehousea spinata, Aquilapollenites conatus, _A. dispositus and Scollardia normanensis, is equivalent to Srivastava's _W. spinata zone and zone 2 of the Bonnet Plume Formation (Rouse & Srivastava 1972). UPPER CRETACEOUS TERTIARY m n OJ r~ O For t U n i o n Q TO r- jj Ul a ia a 1 a g  g e t t c Q- 3*. 70 o a TJ a i 0 A • 0) X r> jr T u llo c k i— rt cr o < 3 - C o a a n 3* X o O 3 ! . a 3 3 to O n d M o o n t j c O rt x- 0 c 3 0 i 9 — 1 9 o rre lo t io n  <  X* 73 T) O X" 0 < x- ~n O a 3 0 0 1 d m a n a> a o •o a < m 0 9 3 a. 3" 9 3 c O L B a ttle - o 0 3 -n a 3 n 3" 3 a 3 1 1 ] R a v e n s c r o g S ou th - e o ite rn  A lb e rta -< 0 0 -~ L e a  P a r k  -n o O J Edm o n t o n I "O > n 1 9  6  7  ) .  3 T> o 0 3 o c •o •o a n L e a  P a r k  3 o O a. 3 o 3 9 . a TJ O * r — 0 i 9 K n e e h i 1 1 $ '• C •o •o <» 1 1 1 | 4 o o 3 0 V* 7C a •o o o — 9 <r 3 a — -" o 0 — a 9 VI 3 [io n s a lo n g a a a o c t» o 8 r o : e a J A o 3 (0 m 3 0 3 rt 4 1 1 ! 1 OJ a H a o c TJ o 1 •o a IM j r o T> 0 0 | W e s te rn A lb e rta • 0 CL •O Ov •O 3" 9 3 a. -o -o l i t t l e Bear East Fork 1 t— O ° x- 9 1 —H o a o F o rt N o rm a n A re a 0 M o n s I e r 1 1 1 s o 3 M 9 o O g i 1 y i e M o u n ta in s 1 C 3 a B o n n e t 1 1 1 1 •o c 3 a O 0 3 i 3 9 J Pee 1 R iv e r A re a 1 -o 1 R e i n d e e r 1 - 0 C a rib o u H ills O 1 M o o t e C ha n n e 1 1 1 1 1 W e st e r n  M a cke n zie D e lto SAN TON. CAM PAN. MAASTRICHT. PALEOCENE EOCENE > o m to 18 Most species of this assemblage have been reported by Leffingwell ( 1 9 6 6 ) , Norton & Hall ( 1 ° 6 9 ) . Srivastava ( 1 9 7 0 ) , Stanley ( 1 9 6 5 ) . and Tschudy (1966) as being restricted to the uppermost Cretaceous. Wodehouse fimbriata which may be indicative of a transition zone straddling the Cretaceous-Tertiary boundary (Srivastava 1 9 7 0 ) , was not found in the Tate Lake succession, neither was i t s presence recorded by Leffingwell ( 1 9 6 6 ) , Tschudy ( 1 9 6 6 ) , Snead ( 1 9 6 8 ) , Eliuk (1969) nor Rouse & Srivastava (1972) from essentially contempo- raneous strata. However, the writer recovered Polycolpites pocockii, Tetracolpites reticulatus, Cardioangulina diaphana, Leptolepidites tenuis and other palynomorphs that have been recorded in associa- tion with W_. fimbriata by Stanley ( 1 9 6 5 ) , Norton & Hall ( 1 9 6 9 ) , and Srivastava ( 1 9 7 0 ) . These are from the L-section (N 64°38"; W 1 2 5 ° 5 4 ' ) on a tributary of the East Fork River to the north of the E-section. The change in the microflora from T.L.II to T.L.III substanti- ates the observation of Tschudy (1966) that: " a marked palynological change occurs at the level of the f i r s t definite lignite." In the Maastrichtian East Fork Formation no coal seams exceeding one foot in thickness were seen by Dr. C. Yorath (pers. comm.). In the E-section the only coal noted was a 1.5 meter seam with shale partings above which the change in palynomorph assemblage takes place. Here most of the aquiloid and a l l of the proteaceaeous species disappear together with the bulk of the Maastrichtian assemblage. However, most fern spores and gymnospermous pollen 19 continue. Taurocusporites segmentatus, Bacu.latisporites comauensis, B_. ilexiformis, Osmundacidites wellmanii and Varirugosisporites cf V. tolmanensis locally abundant in the Upper East Fork Formation are common throughout the lower Tate Lake conglomerates and dis- appear above a diagnostic ash horizon (Fig. 4 ) . Sequoiapollenites paleocenicus, S. polyformus, Interaperturopollenites cf. _I_. magnus, and Taxodiaceaepollenites hiatus, which make their f i r s t appearance above the coal also disappear together with this characteristic fern assemblabe. The increase in bisaccate gyrnnosperm pollen is noticable from T.L.I to T.L.II, also documented by Srivastava ( 1 9 7 0 ) , but very striking between T.L.II and T.L.III. Norton & Hall ( 1969) state 1 "The abundance of vesciculate types such as Abietineaepo11enites microalatus forma microalatus and Podocarpus otagoensis is in direct contrast to the situation in the Upper Cretaceous assemblage where these types are virt u a l l y absent." The bisaccate pollen are dominant in the upper part of the Tate Lake conglomerates where they are in common association with Paraalnipollenites confusus, Betulaceoipollenites & Alnipollenites spp. , Tricolpites l i l l e i and T_. hians. Pollen tetrads of probably typhaceaeous-ericaceaeous a f f i n i t y occur here for the f i r s t time, which seems comparable to the microfloral changes in the Upper Tullock Formation (Fort Union Group) recorded by Leffingwell ( 1 9 6 6 ) . The T.L.III assemblage zone seems most correlative with the assemblages of the Tullock Formation (Leffingwell 1966, Tschudy 1966, Norton & Hall 1 9 6 9 ) , the post-Brazeau beds (Eliuk 1 9 6 9 ) , zone 3 of the Bonnet Plume Formation (Rouse & Srivastava 1972) and 20 Tertiary deposits of Spitzbergen reported by Manum ( 1 9 6 2 ) . The closest palynomorph correlation is noted with Manum's Spitzbergen assemblage derived from beds containing leaf impressions identical to those described by Dawson (1889) from the Mackenzie River ex- posures near Fort Norman, which Bell (19^9) compares with his post- Brazeau leaves from Albertai "Those (species) identified comprises Chladophlebis groenlandica, Elatocladus (Taxites?) o l r i k i , Trochodendroides arctica, PterosT)ermites whitei, Acer arcticum, Nordenskioldia borealis. Two of these species, namely Cladonhlebis groenlandica and Elatocladus o l r i k i are present in the Paleocene post-Brazeau beds of central Alberta. Pterospermites whitei and Acer arcticum are both members of the Fort Union flora and Nordenskioldia. borealis occurs in the Arctic Tertiary. The f l o r a , accordingly, is considered definitely Paleocene, although i t may be somewhat older than the Paskapoo flora." Closely related to, and possibly synonymous with Pterospermites whitei is Pterospermites spectabilis reported from the Mackenzie leaf f l o r a by Dawson (1889) also cited by Manum (1962) from Spitz- bergen and described as Credneria spectabilis by Koch (1963) from the Lov/er Paleocene of Greenland. Dawson (1889) and Manum (1962) also l i s t Glyptostrobus ungeri, Sequoites langsdorffi and Taxodium distichum cf Metasequoia occidentalis to which the palynomorph species Taxodiaceaepollenites hiatus, Sequoiapollenites polyformus and S. paleocenicus are related. Metasequoia occidentalis leaves occur abundantly in the Tate Lake conglomerates and the palynomorph assem- blage is correlative with the assemblage from the leafbearing strata near Fort Norman (Rouse & Brideaux pers. comm.).and the Spitzbergen assemblage (Manum 1 9 6 2)5 particularly with the latter in that 21 tiliaceous, juglandaceous and ulmaceous pollen are absent, Metase- quoia and taxodiaceaeous pollen are very common, and spores locally exceedingly abundant. An influx of juglandaceous, ulmaceous and e r i - ceceous pollen is recorded by Leffingwell ( 1 ° 6 6 ) and Norton & Hall ( 1 9 6 9 ) from the upper part of the Fort Union Group. If there is a continuous sedimentary record as the persistence of the Taurocuspo- rites-Baculatisporites-Varirugosisporites assemblage from the T.L.II into the T.L.III seems to indicate then the equivalent to the Upper Fort Union in the Tate Lake conglomerates probably has been removed by erosion. Manum argues that Tsugaepollenites sp., occurring at Forlandsundet but not in the main Tertiary basin of Spitsbergen 80 kilometers away, indicates a difference in age between the two rock series. In the Tate Lake l o c a l i t y , Tsugaepollenites sp. occurs only in the C-section ( F i g . 3 ) . but is absent in the other sections a l l within a radius of 5 kilometers, which in this particular case at least suggests a facies variation rather than any marked difference in geological age. 22 PALEOECOLOGY Any assessment of the paleoecology of the Tate Lake strata i s dependent on the recognition of the main climatic, physiogra- phic,' and water-to-land ratio factors that prevailed during the time of their emplacement. The separation of the continents in Lower Cretaceous time i s well documented by paleomagnetic data and sedimentological evidence (Smith 1971). If during the greater part "of the Cretaceous three or more isolated continental blocks were present, then three or more f l o r a l groups could have evolved independently of each other. Relative to t h i s , Krutzsch (1967) has suggested that after the Laramide* and early Alpine-Himalayan orogenies re-established landbridges at the end of the Cretaceous there were three broad f l o r a l groups in Europe in a state of competitive interaction during the early Tertiary (Fig.7): I. An Upper Cretaceous Normapollis group in Europe, whose western North American equivalent i s the aquiloid and proteaceous element found in T.L.I & T.L.II. At that time Siberia and western North America formed one continental block separated from Europe and eastern North America by epicontinental seas. I I . An Arctotertiary group, present in the North (unspecified) already during Upper Cretaceous times, advancing during cold phases and retreating during warm phases (Krutzsch favors c y c l i c a l climatic variation rather than a uniformly slow warming up or cooling down). It is this group which constitutes the major angiosperm f l o r a l element of T.L.III i.e. the deciduous trees, I I I . An Eocene-paleotropical group, which in Europe during the middle and upper Paleocene crowded out the Normapollis group completely. This group, characterized by t i l i o i d and caryoid types, does not appear in either the Tate Lake or Bonnet Plume Formations, However, this group has been reported in western North America from Upper Paleocene and Eocene deposits. 23* F i g . 6 . Schematic temperature curve of the early Tertiary "the western United States and Colombia, South America ( after van der Hammen, 1961, and Dorf, 1969 ). F i g . 7 , Schematic diagram of climatic and f l o r a l changes in Central Europe ( after Krutzsch, 1 9 6 7 ) . (23 % 0-j Monocolpiles 20- medius group 30- 40- 50 J TROPICAL SUBTROPICAI WARM TEMP. ^ TFMPFRATF UPPER CRETACEOUS PALEOCENE EOCENE Generalized curve of M medius group,Colombia, redrawn fo fit the original scale of the temperature curve for the western United States Temperature curve for the western United States (after Dorf) ( Adopted from von der Hammen, 1961) F i g . 6 • • N o r m a p o l l e i G r o u p — — — — A r c f o - T e r t i a r y I I + + + P a l e o t r o p i c 11 rrr*r*r probable posi t ion of Ta te L a k e palynomorph a s s e m b . F ig . 7. Schematic d i a g r a m of c l i m a t i c and f lo ra l c h a n g e s ~ in Cen t ra l Europe a f te r K r u t z s c h 1967. 24 According to Krutzsch a l l three groups formed a certain propor- tion of the total flora during each time interval, i.e. Arcto- tertiary elements were present but relatively rare during Maastrichtian "times (cf. T.L.I), but increased rapidly near the Cretaceous-Tertiary boundary. This i s in complete agreement with the findings in T.L.II and T.L.III and the results of a l l workers mentioned, above. Comparable results were obtained by Axelrod ( 1 9 6 6 ) , Dorf ( 1 9 6 9 ) and Lebedev (in Zaklinskaya 1967) working with leaf assemblages.(see F i g . 6 ) , Krutzsch*s f i r s t minimum flora (Fig.7) shov/s optimum condi- tions for Arctotertiary immigrants, in which alnoid, ulmoid, betuloid and bisaccate pollen were more abundant than either before or after. V/ith the exception of the ulmoid types, this i s the situation in zone 3 of the Bonnet Plume Formation (Rouse and Srivastava 1 9 7 2 ) , T.L.III at Tate Lake (this report), and the Spitzbergen palynoassemblages, reflecting a climatic depression that probably affected most of the Northern Hemisphere at that time. A l l of these minimum floras are intimately associated with coal seams. Many hypotheses about coal formation have been proposed in the past, an excellent summary is given by Francis (1961) and Jansa (1972) discusses a model which may be applicable to the Tate Lake coals. According to Schwarz bach (19^3) the greatest accumulation of organic material of continental origin today occurs in regions where the rate of plant growth exceeds the rate of decomposition of plant materials in soils and swamps (Fig,3) I S f Fig. 8 . Relationship between plant growth, decomposition and rate of accumulation of plant debris. A = rate of plant growth (maximum at temperature of about 25 C); B 1  = decomposition of plant material in s o i l s , Bg, in swamps. The shaded area indicates where growth i s faster than decomposition, i.e. where organic matter can accumulate ( after Mohr, and van Baren, 195^ ). Fig. 9 . Present distribution of peat bogs ( after Frueh and Schroeter, simplified from von Buelow's "Moorkunde", 1925, in Schwarzbach's "Climates of the Past", 1963 77 Fig - 8 26 i.e. most peat bogs at present are forming in temperate or cooler climates, or in high mountain ranges of the tropics e.g. the Ruwenzoris and Andes. Similarly black humic soils (chernozem) are not common to the tropics. Although Sphagnum-type spores occur throughout the Tate Lake strata they, are not very abundant and do not support an interpretation that the lignites are derived mainly from peat bogs. The abundant taxodiaceaeous pollen and fern spores associated with the Tate Lake lignites seems to reflect present day conditions in e.g. Dismal Swamp, North Carolina, where Taxodium, Juniperus and alli e d species occupy the swamp, while Pinaceae are restricted to the higher areas (Moore 1950)» which is indicated by the abundance of bisaccate grains in the shale stringers of the thick Tate Lake conglomerates. The rate of plant decomposition can be further retarded by rapid burial in the form of intermittent but progressive subsidence of the substratum on which the coal swamp forest grew coupled with an increased rate of sedimentation. The subsiding sedimentary basins where these coal forests grew have been postulated by Mountjoy (1967) who holds that: "The Bonnet Plume Formation post dates most of the folding and faulting of the Richardson Mountains and are together with the Moose Channel Formation and Monster Formation products of this late Cretaceous (Laramide) orogeny . . . The Bonnet Plume, Monster and Moose Channel Formations were deposited at approximately the same time as the Edmonton and Paskapoo Formations of western and central Alberta." Since the Upper East Fork Formation and the Tate Lake conglomerates correlate palynologically with the Bonnet Plume Formation i t seems they v/ere deposited in a subsiding basin similar to that of the Bonnet Plume, Monster and Moose Channel Formation at about the same 27 geological time. The increase of lignites in the Paleocene recorded by many workers (Leffingwell 1966, Tschudy 1966, Norton & Hall 1969. Rouse & Srivastava 1972 ) can be explained by this coincidence of increase in plant productivity and preservation under optimum climatic conditions and increased subsidence of sedimentary basins. On the basis of a rich and varied coniferous record in association with betulaceous pollen and the apparent absence of Fagaceae, Juglan- daceae and T i l i a Manum (1962) concludes that the climate was tempe- rate. His suggestion thatt- " Alnus was relatively less important in the vegetation, in, and around, the former swamp than the representatives ' of Betulaceae and. probably Myricaceae which contributed the triporate grains." is supported by the Tate Lake data showing a definite increase of myricaceous pollen close to the coal seams and a decrease away from them. In general, thinner and less numerous lignite beds yield smaller numbers of myricaceaeous and taxodiaceaeous pollen and larger numbers of sp. , Tricolpites sp. , and bisaccate grains. Myricipites dubius and Triporopollenites mullensis associated with the Tate Lake lignites were also reported from the Bonnet Plume Formation by Rouse & Srivastava.(1972). The coal seams exhibit a tendency to occur in close vertical proximity separated from another such series by thick conglomerates. Jansa (1972) a t t r i - butes this "grouping" to the lateral shifting of sedimentary lobes in a f l u v i a t i l e environment. Towards the top of the Tate Lake suc- cession the number of coal seams decreases perhaps indicating that u p l i f t and consequent sedimentary changes created unfavourable con- ditions for the formation of coal beds. Possibly a l l u v i a l fans of the rising Mackenzie Mountains prograded over the whole area and 28 terminated coal formatiosi. According to Moore (1950) t "The coal-forming processes ended with the elevation of the Rocky Mountains as i t did in the east with the rise of the Appalachians." It i s interesting to note that many of the above features are also associated with the Permian Karoo coals and the Glossop- teris flora of Gondwanaland (Schwarz bach 19^3)• During fieldwork in Tanzania (East Africa) the writer observed many coarse immature clastic sequences between Karoo coal seams with shale stringers from which abundant Permian bisaccate grains were extracted (Hart 1 9 6 3 ) , probably indicating upland vegetation. The feldspars in these elastics were well preserved which is uncommon for sediments deposited under tropical conditions. Glacial t i l l and striations associated v/ith the Karoo both in South and East Africa, and often quoted as evidence of continental glaciation of the Southern Hemisphere, seem to support a temperate rather than tropical climate during the formation of the Karoo coal beds. A combination of worldwide cooling, at least in the Northern Hemisphere, and local mountain u p l i f t may account for the Tate Lake minimum flora sensu Krutzsch and the associated lignite seams. Leopold and MacGinitie (1972) state thats "Sgme 5,000 feet of regional u p l i f t , equivalent to an 18 C lowering of the average annual temperature using the average lapse rate probably alone could have caused regional cooling that shaped, the trend toward a simplified. Cordilleran flora." The Tate Lake Formation in the study area at present occurs between 2000 and 30°0 feet above sea le v e l . The environment of deposition could have been higher during the Paleocene i f subsidence con- tinued after that time, but i t seems unlikely that mountain u p l i f t 29 alone caused the cooling of climate which so drastically affected the contemporaneous f l o r a . In summary, the paleoecological conditions in the Tate Lake area during the Upper Maastrichtian wore very similar to those described by Rouse & Srivastava (1972) for the Peel River area. The orogenic pulse which brought the Cretaceous to a close was just beginning, with the whole area rela t i v e l y stable and of low r e l i e f judging from the fine grained sediments and abundant paly- nomorphs. The great species diversity in the Maastrichtian ir.di-* cates warm temperate to subtropical conditions. When orogenic act i v i t y began or became more intense, as evidenced by many volcanic ash beds and an increase of coarse e l a s t i c s , the climate deteriorated markedly in the Tate Lake area,accompanied b/a tempe- rate flora characterized by very low species diversity. It appears that Metasequoia, Taxodium, Glyptostrobus and locally Tsuga were associated in coal swamps with an abundant understorage of ferns, whereas Pinus, Picea and Cedrus dominated the surrounding uplands. Of the angio'sperms present, the Myricaceae appear to be the only group that competed successfully with the conifers in the swamp environment. The verti c a l succession of li g n i t e s interbedded with cl a s t i c units suggests frequent burial of coal swamps in inter- montane basins with continuous subsidence and sedimentation un t i l u p l i f t exceeded viable conditions for coal swamp vegetation and ' terminated coal formation in the area. 3 0 ABSOLUTE AGE CONSIDERATIONS The significant f l o r a l changes between the Late Cretaceous and Early Tertiary noted by Axelrod (1966), Bell ( 1 9 ^ 9 ) . Dorf ( 1 9 6 9 ) , Leffingwell (1966), Norton & Hall (1969). Rouse & Srivas- tava ( 1 9 7 2 ) , Stanley ( 1965) and Tschudy ( 1966) were also observed in the Tate Lake succession and seem to reflect an essentially synchronous cooling of climate in the period around 6O-3 million years ago. Most workers agree that sedimentation was essentially continuous during that time and apparent unconformities are local in nature e.g. channeling and cross-bedding (Tschudy 1 9 6 6 ) . Major orogenic activity during this time is reported by many workers and reflected by the widespread occurence of volcanic ash horizons, many of which have been dated. K-Ar dates of 6 1 . 7 to 6 3 . 6 million years have been reported for the "Z" coal seam at the boundary of the Hell Creek and Tullock Formations, above which a major change in microflora takes place in Montana and Wyoming (Folinsbee et al in Norton & Hall 1969 and Folinsbee et al 1 9 7 0 ) . i The Ardley seam above the Nevis coal from which Srivastava reports a change in microflora in Alberta is dated as 6 2 . 6 million years (Folinsbee et al 1 9 7 0 ) . A volcanic ash layer which occurs 225 meters above the .coal seam at which the major change in microflora occurs at the Upper East Fork Formation-Tate Lake conglomerate boundary has been dated as 56-1.7 million years (UBC # C-1*0. What is apparently the same volcanic ash horizon 2 kilometers east of the Tate Lake loc a l i t y was sampled by Rouse and dated i n two runs as 5^ and 5 6 - 3 million years (UBC # R - 6 8 - l ) . A minor ash layer about 31 34 meters higher up was dated by K-Ar as 5 1 - 1 . 6 million years (Fig. 3 ) - Not considering the possibility of Argon leakage, which would give a younger date for the ash horizons, I conclude that the lignite just above which the marked change in palynoassembla- ges takes place is somewhat older than 56 million years, based on the 225 meters of strata separating i t vertically from the mea- sured, and dated ash horizon. Since the sedimentation rates in the Tate Lake conglomerates are not known at present no exact date can be given. However the evidence from palynostratigraphic studies of the Upper East Fork Formation and the Tate Lake conglomerates seems to suggest that these strataare part of the Hell Creek-Fort Union type formational sequences (Fig. 5) that have been studied along the eastern flank of the Rocky Mountains from Wyoming to the Peel River. In most of these formational sequences the Tertiary- Cretaceous boundary can be placed near the f i r s t major lignite series where a relatively sudden change from warm-temperate Maastrichtian to temperate Paleocene microflora and leaf flora takes place.The numerous coal seams in the Fort Union type strata to which the Tate Lake conglomerates belong seems to suggest that sedimentation was continuous. Since the Monster, Reindeer and . Moose Channel Formations to the north and west of the Bonnet Plume area were laid down under similar environmental conditions at about the same geological time (Mountjoy 196?) correlative changes in palynoassemblages with the Bonnet Plume and Tate Lake strata could be expected. 32 SUMMARY AND CONCLUSIONS Sedimentary strata near Tate Lake at the headwaters of the East Fork River, south of Norman Wells, N.W.T., contain two dis- tinct lithological units. The lower one is characterized by soft brown and grey siltstones and shales and on the basis of palyno- logical evidence referrable to the Upper Maastrichtian of the East Fork Formation. The upper unit, characterized by thick cong- lomerates and closely spaced lignites interbedded with siltstones, shales, many volcanic ash layers and minor sandstones, contains a Paleocene palynoassemblage and is informally described as the Tate Lake conglomerates. Palynological data from the Upper East Fork Formation show that the Mancicorpus gibbus (T.L.I) and Wodehousea spinata (T.L.II) palynostratigraphic zones of Alberta are present at Tate Lake, N.W.T.. These two zones are also correlative with the palynoassemb- lages contained in the type Lancian (Hell Creek Formation) of Mon- tana and Wyoming as well as part of the.Bonnet Plume Formation (zone 2 ) , N.W.T.. The palynoassemblage of the Paleocene Tate Lake conglomerates (T.L.III) is correlative with the microflora of the Upper Bonnet Plume Formation (zone 3 ) i N.W.T., the post-Brazeau beds of the Alberta Foothills, and the Lower Fort Union Group of Montana and Wyoming. Reworking of a Mississippian-Albian microflora is very noticable in the Paleocene strata but very uncommon in the Upper East Fork examined. Its occurrence may be useful in helping to identify the Cretaceous-Tertiary boundary in subsurface o i l ex- 33 ploration in the Mackenzie lowlands. The East Fork-Tate Lake palynoassemblages are correlative with most Hell Creek-Fort Union type f l o r a l sequences ranging from Wyoming to the Peel River area. They reflect a major local and possibly worldwide climatic change at the Cretaceous-Tertiary boundary, associated with major mountain u p l i f t towards the end of the Cretaceous which resulted in: l / the establishment of landbridges, with the development of a uniform f l o r a over most of the Northern Hemisphere, and the extinction of endemic Maastrichtian f l o r a l elements; 2/ the formation, of subsiding basins with optimum conditions for. coal accumulation during Paleocene times. The lignites of the Tate Lake conglomerates were formed under temperate climatic conditions probably in close proximity to the mountains during periods of volcanic a c t i v i t y . Sedimentation was continuous without major unconformities except local channelling and cross-bedding. The palynostratigraphic data from the Upper East Fork Forma- tion and the Tate Lake conglomerates suggests that they are time equivalent with the Hell Creek-Fort Union type formational sequen- ces. K-Ar dates from the upper part of the Tate Lake conglomerates suggest a younger data but no conclusions can be reached un t i l the c r i t i c a l horizons can be radiometrically dated. 34 REFERENCES Axelrod, D.I. 1966. A method for determining the altitudes of Tertiary floras. Paleobotanist v o l . 1*4-, pp. 144-171. B e l l , W.A. 1949« Uppermost Cretaceous and Paleocene floras of western Alberta. Geol.Surv.Can.Bull. 13, pp.21-28 Dawson, J.W. 1 8 8 9 , On f o s s i l plants collected by Mr. R.A. McConnel, ort Mackenzie River, and by Mr. T.C.Weston, on Bow River. Roy.Soc.Can.Trans, vol 7» sec.4, pp. 6 9 - 7 4 . Dorf, E. 1 9 6 9 . Paleobotanical evidence of Mesozoic and Cenozoic climatic changes. Proc.N.Am. Paleont. Convention: 323 -346. Eliuk, L.S. 1969<> Correlation of the Entrance conglomerate, Alberta by palynology. M.Sc, thesis, Univ. of Alberta, 143 pages, unpubl. Francis, V/. 1 9 6 1 . Coal, i t s formation and composition. Edward Arnold Publ. Ltd.. London, Ch. 1. Hart, G.F. 1 9 6 3 . Microflora from the Ketewaka-Mchuchuma coalfield, Tanganyika(Tanzania). Geol.Surv.Tanz.Bull. 3 6 , 27 pages. Hart, R.M. 1 9 4 4 . Final geological report on Gravel River and. East Fork of L i t t l e Bear River, Kay Mountains and Summit Anticline. Canol # 10 Report, unpublished. Hume, G.S. 1954 . The Lower Mackenzie River area, N.W.T. and Yukon. Geol.Surv.Can.Mem. 173, pp. 3 - 5 , 4 5 - 5 5 . Jansa, L. 1 9 7 2 . Depositional history of the coal-bearing Upper- Jurassic-Lov/er Cretaceous Kootenay Formation, southern Rocky Mountains, Canada. Geol.Soc.Am.Bui. vol. 8 3 . pp. 3 1 9 9 - 3 2 2 2 . Koch, B.E. 1 9 6 3 . Fossil plants from the Lower Paleocene, Northwest Greenland. Meddelelser om Groenland, Bd. 172, Nr. 5» Krutzsch, W. 1959- Mikropalaeontologische Untersuchungen in der Braunkohle des Geiseltales. Geol.Bein. 2 1 , 2 2 , pp. 1 3 8 - 1 4 3 . 1967. Der Florenwechsel im Alttertiaer Mitteleuropas auf Grund von sporenpalaeontologischen Untersuchungen. Abh.zentr.geol.Inst., H. 10 , pp. 1 7 - 3 7 . Leffingwell, H.A. 1 9 6 6 . Palynology of the Lance (Late Cretaceous) and Fort Union (Paleocene) Formations of the type Lance area, Wyoming. Geol.Soc.Am.Spec.Paper 127 , pp. 1-64. Leopold, E.B. & MacGinitie, H.D., 1972. Development & Af f i n i t i e s of Tertiary Floras in the Rocky Mountains. Ch. 12 , pp. 164, in "Flo r i s t i c s & Paleofloristics of Asia & Eastern North America", A. Graham, Elsevier Publ. Co., Amsterdam. Manum, S. 1 9 6 2 . Studies in the Tertiary flora of Spitzbergen, with notes on the Tertiary flora of Ellesmere Island, Greenland and Iceland. Norsk Polarinst. Skrifter 125 , 127 pages. Moore, E.S. 1 9 5 0 . Coal. Wiley & Sons Publ., New York. pp. 152 . 3 5 Mountjoy, E.V/. t°67. Upper Cretaceous and Tertiary stratigraphy, northern Yukon Territory and northwestern d i s t r i c t of Mac- kenzie. Geol,Surv.Can.Pap. 66-16, 69 pages. Norton, N.J. & Hal]., J.W, 1969. Palynology of the Upper Cret- aceous and Lower Tertiary in the type l o c a l i t y of the Hell Creek Formation, Montana, U.S.A., Palaeontographica 125, Abt. B, 64 pages. Potonie, R. 1956« Synopsis der Gattungen der Sporae dispersae, Beih.Geol. Jb.,H. 23, pp. 33.3^. Robinson, P. 19?2. Geological Atlas of the Rocky Mountain Region, U.S.A.. Rocky Mnt, Assoc.Geol.HirschfeId Press, Denver,Colo,, Rouse, G.E. & Srivastava, S.K, 1970. Systematic revision of Aquilanollenites Rouse. Can.Jour.Bot. 48, no, 9» PP« 1591-1601. " 1972. Palynological zonation of Cretaceous and Early Tertiary rocks of the Bonnet Plume Formation, Northeastern •Yukon, Canada, Can. Journ.Ear• S c i . 9* no. Q> PP. ll63~H79o Samoilovich, S.R. & Mtchedlishvili, N.D. I96I. (Pollen and spores of western Siberia, Jurassic to Paleocene). Trudy Vses.Neft.Nauk.-Issled Geol„-Razv,Inst,, Leningrad 177, 657 pages. Samoilovich, S.R. 1967. Tentative botanico-geographical sub- division of northern Asia in Late Cretaceous time. Rev. Palaeobot.Palynol. 2, pp. 127-139. Schwarzbach, M. 1963. Climates of the Past. pp,60-6l. Transl. by Muir, R.O., D, Van Nostrand Co., London. Shafiqullah, M. I963. Geochronology of the Cretaceous-Tertiary boundary, Alberta, Canada. M.Sc. thesis, Univ. of Alberta, 65 pages, unpublished. Singh, C. I 9 6 3 . Palynology of the Mannville Group (Lower Cret- aceous), central Alberta. PhD. thesis, Univ. of Alberta, 4 l 4 pages, unpublished. Smith, A.G. 1971. Continental D r i f t , in "Understanding the Earth", 6h. 15, pp. 2 1 3 - 2 3 2 ,.M . I . T . Press. Snead, R.G. 1969. Microflora^ diagnosis of the Cretaceous- Tertiary boundary, central Alberta. Research Council of Alberta B u l l . 25, 147 pages. 36 Srivastava, S.K, 1. ? 6 8 , Angiosperm microflora of the Edmonton Formation, Alberta,' Canada. Ph.D. thesis, Univ. of Alberta, 343 pages unpublished. 1 9 7 0 . Pol.len biostratigraphy and paleoecology of the Edmon- ton Formation (Maastrichtian), Alberta, Canada, Palaeogeogr. Palaeoclimatol. and Palaeocol. 7, pp, 2 2 1 - 2 7 6 . 1 9 7 2 . Systematic description of some spores from the Edmon- ton Formation (Maastrichtian), Alberta, Canada, Palaeontographica 139B, pp. 1-46. Stanley, E.A. 196*51 Upper Cretaceous and Paleocene plant micro- .fossils and Paleocene dinoflagellates and hystrichosphaerids from northwestern South Dakota. BULL. AM. Paleont. 4 9 , no. 2 2 2 , PP.. 1- 3 7 8 . 1 9 6 9 . The occurrence and distribution of pollen and spores in marine sediments. Proc.First Inter,Conf, on planktonic microfossils, v o l . II, pp. 641-643, I 9 7 O. The stratigraphical, biogeographical, -paleoautecolo- gical & evolutionary significance • .of the f o s s i l group . Triproioctates. Bull,Georgia, Acad.Sci.2 8 , pp. 1-44. Staplin, F.L. i 9 6 0 . Upper Mississippian plant spores from the Golata Formation, Alberta, Canada, Palaeontographica 107B, 40 : pages, Tassonyi, E.J. 19.69. Subsurface geology, Lower Mackenzie River and Anderson River area, d i s t r i c t of Mackenzie. C-eol.Surv. Cara.Pap. 6 8 - 2 5 . Tschudy, R.H. 1966. Palynology of the Cretaceous-Tertiary boundary in the Northern Rocky Mountains and. Mississippi enbayment regions, Geol.Soc .Am,Pap. 1.27, pp. 64-89. Williams, M.Y. 1922. across northeastern British Columbia, and the geology of the northern extention of the Franklin Mountains., N T W . T , Geol.Surv.Can.Sum.Rept. 1922B, pp. 6 5 - 8 7 . Zaklinskaja, E.D. I 9 6 7 . The early-Paleocene flora of the Northern Hemisphere and palaeofloristic provinces of this age. Abh. zent.geol.Inst. 1.0, pp. 183-18?. 37 APPENDICES AND PHOTOMICROGRAPH PLATES 38 APPENDIX I TAXONOMIC PALYNOLOGY Most palynomorphs recovered from the three assemblage zones of the East Fork and Tate Lake Formations are well known from previous studies, and generally long ranging. However several new species have been discovered which are potentially important as index palynomorphs; these are described formally here. l / Scollardia normanensis n.sp. Form Genus Scollardia Srivastava 1966 emend. 1968 emend. 1966 Scollardia Srivastava; Pollen et Spores, vol.8,no.3» v . p. 5 ^ . 19^8 Scollardia Srivastava; Ph.D. thesis, p. l 6 l Form Genotype: Scollardia trapaformis Srivastava 1966 Emended diagnosis 1 Heteropolar grains with three well developed equatorial projections showing sexinal outgrov/th on both the margins of the colpi and having a convex triangular contour are herewith included in the form genus Scollardia sensu Srivastava. Scollardia normanensis n.sp. Plate II, Fig. 19-21,23 Holotype dimensions: Equatorial diameter 58 microns, polar axis 65 microns Holotype preparation: El ( 3 0 ) ; 100.5/46; Pl.II Fig. 19 Locality: Zone T.L.I & II, sections E & E2, near headwaters of the East Fork of the L i t t l e Bear River. Descriptionfbased on 30 specimens): Heteropolar; tricolpate, short colpi meridional across apices of equatorial projections; sexine along the margins of colpi ending in a thin membranous' f r i l l ; equatorial contour triangular, sides s l i g h t l y convex; 3 9 equatorial projections well developed and pointed at the tips (tips are broken off in many specimens); sexine tectate,baculate; ornamentation st r i a t e , striations discontinuous, often teardrop shaped more or less parallel to each other and arranged perpen- dicular to the margins of the equatorial projections. Size rangei Equatorial diameter 58 to 76 microns; polar axis 45 to 60 microns. Remarks« Scollardia normanensis seems to f i l l stratigraphically and paleoecologically the niche of Scollardia trapaformis from which i t di f f e r s in size and the development of polar projec-:. tions. Although Scollardia normanensis i s loc a l l y more abundant in the W. spinata zone ( T . L . I I ) i t i s also a common component of the M. gibbus zone ( T . L . I ) . Specific epithet« normanensis refers to the Fort Norman area. 2/ Baculatisporites ilexiformis n. sp. Form Genus Baculatisporites Thomson & Pflug 1953 1953 Baculatisporites Thomson & Pflug; Paleontographica, v o l . 94 Form GenotypeJ Baculatisporites (as Sporites) primarius (Wolff) Thomson & Pflug 1953 Baculatisporites ilexiformis n.sp. Plate I V , Fig. 45,46 Holotype dimensionsJ Equatorial diameter 45 microns Holotype preparation! D25(30)j 117.8/50.2; Plate I V , Fig.45, ' 1 Localityi Zone T . L . I I I , section D. Description 1 Equatorial outline subcircular; diameter 35 to 50 microns; exine 0.8 to 1.0 microns; sculptured with clavae and 40 bacula spaced at intervals approximately equal to their diameter as seen from surface view; clavae 2.5 microns high, 0,8 microns in diameter at the> top end which i s usually flattened squarely, base of clavae'somewhat constricted; bacula towards the proximal surface become smaller in size and tend to fuse v/ith each other at the bottom; t r i l e t e scar covers nearly the f u l l radius of the spore and is elevated as a small ridge on the proximal surface; area around the t r i l e t e scar is psilate without ornamentation. Grains are usually folded; in expanded grains the d i s t a l surface hemispherical, and the proximal surface plane to slightly con- cave with the t r i l e t e scar extending as a ridge to the equato- r i a l rim. Remarks. Both Potonie (1956) and Krutzsch (1959) note that smal- le r echinate and baculate osmundaceaeous spores are common in the upper Neogene, whereas larger spores with verrucate, gemmate to clavate ornamentation have only been observed in the lowest Tertieary. The occurrence in theTate' Lake Formation of Baculati- sporites ilexiformis together with both Baculatisporites comau- ensis (Cookson) Potonie, and B_. gemmatus Krutzsch, described from the Paleocene of the USSR (Zaklinskaja 1953) and the lower Tertiary of Spitzbergen (Manum 195*0 » appears to conform v/ith this observation, and hence supports a Paleocene age. B. i l e x i - formis ranges down into the Upper Maastrichtian as does B. co- mauensis. B. ilexiformis i s very distinct from other species of this genus in having clavae very similar to those of Ilex. Specific epithetJ ilexiformis refers to the ornamentation of Ilex. 41 3 / Aquilapollenites adamas n.sp. Form Genus Aquilapollenites Rouse emend. Rouse & Srivastava 1970 Form Genotype Aquilapollenites quadrilobus 1957 Remarks? The taxonomy of this stratigraphically important group of index f o s s i l s i s in a state of flux. The magnitude of the problems can be ascertained by reference to Rouse & Srivastava (1970), Tschudy & Leopold (1971) and Stanley ( - : ) . The writer follows the system proposed by Rouse & Srivastava. Aquilapollenites adamas n.sp. Plate III, Fig. 37, 43 Holotype dimensions* Polar axis 27 microns; equatorial axis 12 microns; distance from centre of polar axis to the tips of equatorial projections 15 microns; maximum breadth of equatorial projections 4 microns. Holotype preparation: A8(20-0-X): 100/41.9; Plate III, Fig.43 Locality: Zone T.L.III, section A, type section of the Tate Lake Formation. Description(based on 7 specimens): Pollengrains with three equatorially situated projections; isopolar with well developed polar extensions; poles conical unles folded or flattened by preservation; equatorial projections moderately long; tricolpate, colpi meridional across equatorial projections, long, almost reaching polar regions; sexine bastionate;ornamentation micro- reticulate, mesh size variable, larger on the body and smaller on poles and equatorial projections. Size range: Polar axis 27 to 28 microns. Specific epthet: adamas refers to the diamond-shaped outline. 42 4 / General remarks about size variation in Aquilapollenites dispositus Mtchedlishvili: The writer counted in excess of 30 specimens and noted a bimodal size distribution v/ith relatively- sharp peaks around 65 and 90 microns. The larger forms have never been recorded before, and may well belong to a'.different species. Electronmicroscopy may establish morphological differences not observable under the light-microscope. Size differenc alone does not seem to be a valid c r i t e r i a for species differentiation. 43 APPENDIX II l / List of species restricted to the T.L.I zone of the East Fork Formationt Liburhisporites adnacus Srivastava Styx minor Norton Aquilapollenites c f . A. amicus Srivastava A, argutus Srivastava A. c f . A. paplionis Srivastava _A, polar is Funkhouser A_. reductus Norton A. reticulatus Stanley Callistopollenites tumidiporus Srivastava Extratriporopollenites.sp. Mancicorpus gibbus Srivastava M. rostratus Srivastava Proteacidites angulatus Samoilovich P. thalmannii Anderson 2/ List of species of T.L.I, and T.L.II zones: Ceratosporites masculus Norris Hamulatisporites hamulatis Krutzsch Retitrilates austroclavatides (Cookson) Krutzsch Schizosporis complexus Stanley Zlivisporites sp. Aquilapollenites conatus Norton , restricted to T.L.II A. dispositus Mtchedlishvili Callistopollenites radiostriatus Mtchedlishvili 44 Cranwcllia c f , C_. rumseyensis Srivastava L i l i a c i d i t e s mirus Srivastava Loranthacites pilatus Mtchedlishvili Mancicorpus pulchor (Funkhouser) Srivastava M. senonicum Mtchedlishvili Profleacidites asper Samoilovich P. crispus Samoilovich P. occallatus Samoilovich Pulcheripollenites krempii Srivastava Retitricolpites foveoloides Pierce Santalumidites sp. Scollardia normanensis n.sp. Tricolpites matauraensis Couper Wodehousea c f . W, gracile Samoilovich W. spinata Stanley 3/ List of longiranging species occurring in a l l zones of the Tate Lake composite section: ' Acanthtriletes sp. Baculatisporites comauensis (Cookson) Potonie B. gemmatus Krutzsch B. ilexiformis n. sp. Concavisporites sp. Deltoidospora sp. Foveotriletes sp. Gleicheniidites senonicus Rouse Hazaria sheopiarii Srivastava 45 Laevigatosporites adiscordatus Krutzsch L. ovatus Wilson & Webster Leiotriletes sp. Leptolepidites bullatus. van Hoeken-Klinkenberg L. tenuis Stanley Lycopodiumsporites sp. Osmundacidites wellmannii Couper Stereisporites antiquasporites (Wilson & Webster) Dettman Taurocusporites segmentatus Stover Varirugosisporites c f . V. tolmanensis Srivastava gymnospermous pollen undifferentiated, including Podocarpites, Abietineaepollenites and Taxodiaceaepollenites spp.. Aquilapollenites dolium Samoilovich Erdtmanipollis pachysandroides Krutzsch E. procumbentiformis (Samoilovich) Krutzsch k/ List of species restricted to the T.L.III zone of the Tate Lake Formation« Phragmothyrites eocaenicus Edwards Cicatricosisporites dorogensis Potonie & Gelletich Cedripites c f . C. parvus Norton Piceapollenites grandivescipites Wodehouse Podocarpites marwickii Couper P. maximus (Stanley) Norton Sequoiapollenites palaeocenicus Stanley S. polyformus Stanley • . S , s p . 46 Taxodiaceaepollenites hiatus Tsugaepollonites sp. Interaperturopollenites c f . I. magnus (Potonie) Thomson & Pflug Alnipollenites sp. Aquilapollenites adamas n. sp. Betulaceoipollenites infrequens (Stanley) Rouse & Srivastava Carpinites c f . C. ancipites Wodehouse Fraxinoipollenites v a r i a b i l i s Stanley Liquidambar sp. Myricipites dubius V/odehouse Paraalnipollenites confusus (Zaklinskaja) H i l l s & Wallace Tricolpites anguloluminosus Anderson T. l i l l e i Couper T. hians Stanley Tricolpopollenites c f . T. sinosus Norton Triporopollenites mullensis (Simpson) Rouse & Srivastava 47 f PHOTOMICROGRAPHY Note: a l l figures magnified X 1000 unless otherwise mentioned. Plate I i Fig. 1, Mancicorpus ro s t r a p s Srivastava Fig. 2 , 3 . Mancicorpus gibbus Srivastava Fig, 4. Aquilapollenites reductus Norton Fig. 5« Aquilapollenites reticulatus Stanley Fig. 6. Aquilapollenites polaris Funkhouser Fig, 7. Aquilapollenites dolium Samoilovitch Fig. 8, Aquilapollenites cf A, paplionis Srivastava Fig, 9. Aquilapollenites argutus Srivastava Fig, 1 0 . Libumisporites adnacus Srivastava F i g . l l . Rousea s u b t i l i s Srivastava Fig.1 2 . Proteacidites angulatus Samoilovitch 47 PLATE I. 4&f Plate II i Fig.13. Wodehousea spinata Stanley Fig.14. Aquilapollenites dispositus Mtchedlishvili , shov/ing the larger variety. ( X 440 ) F i g . l 5 i l 8 . Aquilapollenites dispositus Mtchedlishvili , showing the smaller variety. ( X 440 ) Fig.16. Santalumidites sp. Fig.19-21. Scollardia normanensis n, sp. ( X 440 ) , 19. polar view, 20. equatorial view, 21. grain with tips of equatorial projections removed, common occurrence. Fig.22. Aquilapollenites conatus Norton Fig.23 . Scollardia normanensis .n,. sp. , showing tear drop ornamentation. Fig.24. Proteacidites occallatus Samoilovich 48 P L A T E II 45 f Plate III i Fig.2.6. Pulcheripollenites krempii Srivastava Fig,27. Policolpites pocockii Srivastava Fig.28. Tetracolpites reticulatus Srivastava Fig.29. Tricolpites matauraensis Couper Fig.30. Proteacidites crispus Samoilovich Fig.31. Proteacidites sp. Fig.32. Extratriporopollenites sp. Pig.33. Wodehousea cf W. gracile Samoilovich Fig.34. E rd tman i po11i s procumbentiformis (Samoilovich) Krutzsch , common appearance. Fig.35. cf Gothanipollis Fig.36. Cranwellia cf C. rumseyensis Srivastava Fig.37• Aquilapollenites adamas n.sp. Fig.38. Loranthacites pilatus Mtchedlishvili Fig.38,40. Callistopollenites radiostr.iatus Mtchedlishvili , showing different f o c i . Fig.4l. Aquilapollenites catenireticulatus Srivastava Fig.42. L i l i a c i d i t e s mirus Srivastava Fig.43. Aquilapollenites adamas n. sp. ( X 2000 )  50 f Plate IV t Fig.44, Taurocusporites segmentatus Stover Fig.45,46. Baculatisporites ilexiformis n.sp. Fig.47. Sequoiapollenites sp. Fig.48. Sequoiapollenites paleocenicus Stanley cf Metasequoia. Fig.49,50» Varirugosisporites cf V, tolmanensis Srivastava Fig.51. Taxodiaceaepollenites hiatus cf Glyptostrobus Fig.52,53. Tsugaepollenites sp. Fig.54. Cedripites sp. Fig.55» typhaceaeous pollen tetrads Fig.56.. Tricolpites angu 1 oluminosus Anderson Fig*57* Tricolpites l i l l e i Couper Fig.58. Myricipites dubius V/odehouse Fig.59. Triporopollenites mullensis (Simpson) Rouse & Srivastava Fig.60. Paraalnipollenites confusus (Zaklinskaja) !  H i l l s & Wallace Fig.6l, Tricolpites hians Stanley Fig.62. Fraxihpipollenites v a r i a b i l i s Stanley 50 51 f Plate V J Note« a l l figures magnified X 440 unless otherwise stated. Fig.63. Appendicisporites perplexus Singh, X 1000 Fi g .6 4 . A. c f . A. trichacanthus , Fig.6 4 and 65 X 1000 Fig.65. Cicatricosisporites dorsostriatus (Bolkhovitina) Singh Fig,66. Hystrichosphaeridium irregulare Pocock Fig.67. Cyclonephelium c f . C. distinctum Fig.68. Palaeoperidinium cretaceum Pocock Fig.69. Odontochitina sp. Fig,70. Spiridinium sp. Fig.71. Deflandrea sp. Fig.72. Baltisphaeridium neptuni Eisenack Fig.73. Ascodinium sp. Fig.74. Baltisphaeridium multispinosum Singh Fig.75. Vittatina sp. Fig.76, Tripartites golatensis Staplin Fig.77. Tripartites inciso-trilobus Waltz Fig.78. Hymenozonotriletes c f . H_. lepidophytes N.B. Microfossils from Fig. 63 to 74 are of Albian, Fig. 75 of Permian, and Fig. 76 to 78 of Mississippian age. 


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