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Home , Bearpaw Formation, Dinosaur Park Formation, Foremost Formation

and Stratigraphy of the Park Formation in Southwestern , . Meagan Gilbert, Luis Buatois, and Robin Renaut Department of Geological Sciences, 114 Science Place, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E2

121/10-07-007-29W3/00

GR BD a. Methods 141/10-23-007-25W3/00 Introduction 100/03-16-007-02W4/00 GR BD 100/06-09-007-04$4/00 GR BD GR BD A regional investigation of the geology and paleontology of the Belly Picks are being made on geophysical well logs A River Group in Southwestern Saskatchewan and Southeastern is 131/13-34-007-21W3/00 A’ using a series of closely spaced, overlapping 190 GR BD 100/07-06-007-05W4/00 in progress. The objectives are to: 1) Place the into Bearpaw/Dinosaur Park cross sections. On average, one well per BD GR Formation Contact

Oldman/Dinosaur paleoenvironmental context utilizing facies models and depositional envi- Park Formation Contact township is picked, however, this is not always (Sequence Boundary) ronments: 2) Establish a sequence stratigraphic framework for the Group possible due to lack of available well data. To Marine Oldman/ Foremost and its associated interfingering formations. Microvertebrate sites of near (HST) Contact date, several hundred picks have been made. Base of

Inter ngering Shoreface/Of shore equivalent age to have been discovered, and are deposits of theForemost andLea Well log analysis has determined that it is Park Formations being processed for paleoecological study. This material is significant, as possible to pick tops for all three formations in it represent the easternmost expression of terrestrial ecosystems in this the Group. Outcrop and core data are being region before final transgression of the Bearpaw Sea 77 million

integrated with facies models to gain paleoenvi- Milk River“Shoulde r” 200 ago. (Datum) ronmental insight. Comparison with outcrop and A A’ a. b. s

r subsurface data from west-central Saskatchewan West East Figure 4. Dip section through Township 7, Range 7W4 to 21W3. West to east dip section showing the contacts between different formations of a Northern e Southern Southwest Horseshoe Y n d

i Maximum Flooding the Belly River Group. Note the interfingering coastal plain and shoreface deposits of the Foremost Formation. The thins to the f Canyon o a Sask e o i Plains

r Formation s m Surface E r i and is ongoing. east, but thickens to the south. In Montana, the OF and DPF are grouped into a single unit refered to as the . Contact n T o P e i

l Bearpaw Formation l i between the OF/DPF is a sequence boundary, with the DPF becoming increasingly mud dominated due to encroachment of the Bearpaw Sea. M

Neogene Laurentian Drift Laurentian Drift Laurentian Drift 1.6 Dinosaur Park Plunging observed between the last two wells is due to regional deformation caused by the Coburg Syncline. e Formation c

i Cypress Hills Cypress Hills n o

e Swift Current Swift Current z g o o Porcupine Nexen Battle Creek n Paskapoo e

up

l Hills e

o

r 111/07-02-004-27W2/00 C Ravenscrag Ravenscrag Fort Union a. Bearpaw/ Transition P a b. Scollard G Oldman Creek 66.4 Frenchman Hell Creek Non-marine DPF/Bearpaw Fm. Battle Battle ? Gamma Ray Std. Res. Formation Density Gamma Ray Neutron Porosity for Sand

iver St. Mary Horseshoe Boundary Whitemud Whitemud Fox Hills River Canyon R Marine Eastend Eastend 0 GAPI 150 2000 k/M3 3000 0 GAPI 150 0.6 V/V 0

y

l s Blood Reserve l Tongues of the Dinosaur Park Formation diachronously interfinger with overlying Bearpaw Formation

c Bearpaw u

e i Bearpaw Bearpaw Bearpaw r r o

o Dinosaur Park

B

e Dinosaur Park e v r e i z

t h Oldman Judith River e i

R Oldman Oldman v

d Foremost p i c o y

u and sands. Core, trace and outcrop data suggest marginal marine conditions were ubiquitious throughout l R l J

p Formation e Foremost s Foremost Foremost Claggett B t a e U e Lea Park Eagle

r Pakowki Pakowki Lea Park Formation M Telegraph Creek the region before final transgression of the Bearpaw Sea. DPF/Bearpaw transition outcrops in the southern Cy- Milk River Milk River C 210 First White Speckled First White Speckled Shale Niobrara Milk River Shoulder o o

d HST d a a

Medicine Hat r r

o press Hills records a coquina (pelycopods, Crassostrea, Anomia, and various gastropods) lag deposit seperat- o l l 0 o o Milk River C C Carlile Formation m ing the formations. This is absent in outcrops recording the transition in the north flank of the Hills near 50 Alberta Saskatchewan 0 km 100

Glacial Drift Creek, suggesting regional transgressive erosion. Terrigenous Clastics MFS Marine Clastics 200 c.

Figure 1. a. Geological formations and nomenclature throughout southeastern Alberta and southwestern Saskatchewan of the DPF/BP Contact late . b. Interfingering of terrestrial and marine sediment shown in a cross sectional diagram through Alberta into TST Uppermost Marginal Figure 5. Core from 07-02-004-27W3. a) Saskatchewan. Marine Deposits (DPF) (TST) Photo taken directly below Bearpaw/DPF contact. Trace and sedimentary struc- TS a. tures suggest a marginal marine environment Geological Framework with brackish water. seams and brackish water signatures commonly mark the transi- 220 b. tion to the overlying marine Bearpaw Forma- The Belly River Group comprises an eastward thinning marginal marine to non-marine tion in the Cypress Hills. Cy. Cylindrichnus P. clastic succession in the Western Canadian Sedimentary Basin. Three for- HST Planolites; Pl. Paleophycus; Te. Teichichnus; mations are formally recognized in the western Canadian Plains. In ascending order, Sk. Skolithos; Sy. Syneresis Cracks. 250 Te these are the Foremost (marginal marine to non-marine; FF), Oldman (alluvial to mar- OF/DPF Contact Te ginal marine; OF), and the Dinosaur Park (alluvial, estuarine, and marginal marine; SB DPF) formations. The Dinosaur Park Formation is a distal, primarily transgressive Transgressive third-order succession, dominated by stacked fluvial sands and siltstones in the lower Surface portion, and muds, silts, and in the upper unit. The DPF is overlain by marine Figure 3.Representative well log from Township 4 Range 27W3 on the southern flank Conclusion and Future Directions of the Cypress Hills. a) The OF/DPF and DPF/Bearpaw contacts are picked based on a shales of the Bearpaw Formation (BP). number of well log signatures. Formation tops are identifiable north of T4, with tops to Outcrop, core, and geophysical well log data are successfuly being combined to map the Belly River Group in b. the south becoming increasingly difficult to discern. Black bar indicates cored interval. the Cypress Hills region of Saskatchewan. This is the first time the group and all of its associated formations Lake b) Detailed sedimentary log of the cored interval from Nexen Battle Creek well. Core Athabasca 230 includes the upper Dinosaur Park Formation and the lowermost Bearpaw Formation. have been studied across western Saskatchewan. Though mapping these formations is possible, it becomes in- a. The lowermost fluvial unit is preserved in the form of overbank, crevasse splay, fluvial, creasingy more difficult to do so south of Township 4. Further investigation is ongoing to determine why this

Reindeer and coal seam deposits (HST). Encroachment of the transgressive Western Interior may be. Lake DPF Seaway is signaled by a transgressive surface, which marks the beginning ofDPF the TST. Backstepping was gradual until the DPF/BP contact, where a dramatic shift in facies Bearpaw Formation Lowermost Fluvial An additional study is currently underway by the author focusing on the vertebrate palentology of the Group occurs, from marginal marine heterolithics to fully marine offshore deposits. The MFS Deposits (DPF) Belly River Group throughout Saskatchewan. An intensive bulk sampling program is in place to aquire a statistically significant OF signals return to progradational clastic wedges of the HighstandDPF Systems Tract. HST: (HST) Lea Park Formation Highstand Systems Tract; TST: Transgressive Systems Tract; SB: Sequence Bround- data set. Ichnofossils and vertebrate are being integrated with sedimentology and sequence stratig- Outcrop Lac La Ronge ary; TS: Transgressive Surface; MFS: Maximum Flooding Surface. OF raphy to provide a comprehensive understanding of paleoenvironmental and paleoecological parameters in the Nexen Battle Creek OF Woodpile Coulee the Dinosaur Park Formation of Saskatchewan. an ew h Legend tc a k s a S References Ripples N Siderite or th Chondrities

n a Figure 2. a) A simplified bedrock map of Saskatchewan highlighting all w e S h Slickensides a tc Root Traces Beavan, N. R., and Russell, A. P., 1999, An elasmobranch assemblage from the terrestrial-marine transitional coal zone (Dinosaur Park Formation: Upper Campanian), Alberta, s k a known Belly River Group outcrop, and location of representative well log and Canada: Journal of Paleontology, p. 494-503. Saskatoon Soft Sediment Ophiomorpha relevant exposure (Figure 4). Black box indicates region under investigation. Deformation Teichichnus 240 Brinkman, D. B., 1990, Paleooecology of the Judith River Formation (Campanian) of Dinosaur Provincial Park, Alberta, Canada: Evidence from vertebrate localities: Palaeogeog- b) Archetypal Dinosaur Park Formation in Dinosaur Provincial Park, Alberta, Planolites raphy, Palaeoclimatology, Palaeoecology, v. 78, no. 1, p. 37-54. Sout Plant Material Skolithos h n a Paleophycus w S e Canada. This formation is characterized by muddy overbank deposits, inclined ask tch a Arenicolites Buatois, L. A., and Mángano, M. G., 2011, Ichnology: Organism-substrate interactions in space and time, Cambridge University Press. heterolithics, and fluvial fine-grained sands in the lowermost beds. The Mollusc Shells Regina Unidentifiable Bioturbation uppoermost portion of the formation consists of marginal marintidally influ- Coal Clasts Cylindrichnus Eberth, D. A., 2005, The geology: Dinosaur Provincial Park: A spectacular ancient ecosystem revealed, p. 54-82. enced sands and muds. This trend is observed in the Cypress Hills of Sas- Glombick, P., Hathway, B., Mei, S., Banks, C., and Hay, D., 2011, Mapping the Belly River Group in Alberta. Alberta Geological Survey Open Report. katchewan. Sh Cl Si VF F