Lower Cretaceous floras of western Canada

1956 ◽  
Author(s):  
W A Bell
Keyword(s):  
Lower Cretaceous ◽  
Western Canada

scholarly journals A NEW GENUS OF ICHTHYOSAUR FROM THE LOWER CRETACEOUS OF WESTERN CANADA

Palaeontology ◽  
2006 ◽  
Vol 49 (5) ◽  
pp. 1043-1052 ◽  
Author(s):  
E. E. MAXWELL ◽  
M. W. CALDWELL
Keyword(s):  
Lower Cretaceous ◽  
New Genus ◽  
Western Canada

McMurray Formation foraminifera within the lower Albian (Lower Cretaceous) Loon River shales of northern Alberta

2007 ◽  
Vol 44 (11) ◽  
pp. 1627-1651 ◽  
Author(s):  
C R Stelck ◽  
F H Trollope ◽  
A W Norris ◽  
S G Pemberton
Keyword(s):  
Lower Cretaceous ◽  
Isotopic Analysis ◽  
Radiometric Dating ◽  
Western Canada ◽  
Fort Mcmurray ◽  
Mcmurray Formation ◽  
Peace River ◽  
Clearwater Formation ◽  
Northeastern Alberta ◽  
Northern Alberta

Early Cretaceous paleogeography and biostratigraphy of western Canada are reviewed in light of a reassessment of foraminiferal and microfloral data from unpublished university theses on the early Albian Loon River shales of the lower Peace River area of northern Alberta (Norris 1951; Trollope 1951). The Loon River Formation, once considered to be an obsolete term, comprises numerous “zones” of foraminifera, radiolarian, and algal cysts, in ascending order Rectobolivina sp., lower Radiolarian zone, lower Leiosphaeridia zone, Haplophragmoides yukonensis, upper Radiolarian zone, upper Leiosphaeridia zone, Trochammina mcmurrayensis, Valvulineria loetterlei, Haplophragmoides topagorukensis, Marginulinopsis collinsi, and Haplophragmoides gigas minor. The upper part of the Loon River Formation, from the upper Radiolarian zone onwards, correlates with the McMurray, Wabiskaw, and Clearwater formations of the Fort McMurray area of northeastern Alberta. Molluscan data from various localities in western Canada indicates that the entire Loon River succession occurred within the early Albian. The presence of Inoceramus dowlingi and Cleoniceras sp. with the Marginulinopsis collinsi microfauna permits correlation of the type Clearwater Formation and type McMurray Formation with the Moosebar Formation of northeastern Bristish Columbia. An anomalous thick sequence of Leiosphaeridia (algal cysts) beds, bounded above and below by radiolarian-bearing strata, occurs in the mid part of the Loon River shales outcropping ~40 km along the lower Peace River. The Trochammina mcmurrayensis microfauna occurs 2–3 m below Inoceramus dowlingi and 30 m above Cleoniceras sp., and above the upper Leiosphaeridia zone. The radiolarian and Leiosphaeridia beds are considered to be the offshore neritic homotaxial equivalent of deltaic strata in the upper part of the McMurray Formation. The mid and lower Loon River shales are potential oil sources for the tar of the McMurray Formation, and this is supported by recent radiometric dating of the tar by Rhenium–Osmium isotopic analysis.

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