Type Locality:

Along the Little Woody River, on the north flank of the Porcupine Hills of Manitoba. The composite type section is located south of National Mills, Manitoba, in Secs. 22 and 23, Twp. 46, Rge. 29WPM.

Distribution:

The Westgate is recognized in eastern Saskatchewan and southern Manitoba, occurring in outcrop along the Manitoba escarpment from the Pasquia Hills of east-central Saskatchewan to Riding Mountain, Manitoba. In this area the member forms a wedge, thickest at 23 to 30 m (75 to 98 ft) in the northwest and thinnest, about 8 m (26 ft) in the southeast.

Lithology:

Noncalcareous shale. The Westgate Member is a fairly uniform sequence of dark grey shales, with rare bentonite seams and subordinate interbeds of silty shale marked by fine-grained quartzose sand in lenses and burrows.

Relationship:

The contacts of the Westgate are conformable; the lower may be gradational or sharp with the Newcastle Sandstone Member (previously the informal Ashville sand), and the upper is sharp with the distinctive Belle Fourche shale, which contains fish fragments and lenses of fine-grained sand near the contact (base of Fish-scale marker beds). The Westgate is the homotaxial equivalent to the siliceous Mowry Shale of eastern Montana and Wyoming or its facies equivalents in the Dakota Formation of south Dakota, Nebraska and Kansas. As the Mowry Shale is traced northeastwards its silica content decreases until the siliceous shale is replaced by the uniform sequence of soft shale which constitutes the Westgate Member in Manitoba and Saskatchewan. The Westgate can be traced directly through the subsurface of western Saskatchewan and eastern Alberta into the lower Colorado Group, where its equivalents between the Viking Sandstone and the base of the Fish-scale marker beds have been referred to as lower part of the Big River Formation (Simpson, 1975).

Other Citations:

Hansen, 1955; McGookey et al., 1972; McNeil and Caldwell, 1981; Price, 1963; Simpson, 1975.

References:

Hansen, D.E., 1955. Subsurface correlation of the Cretaceous Greenhorn-Dakota interval in North Dakota; North Dakota Geological Survey, Bulletin 29, 46 p.

McGookey, D.P., Haun, J.D., Hare, L.A., Goodell, H.G., McCubbin, D.G., Weimer, R.J., and Wulf, G.R., 1972. Cretaceous System. In: Geologic atlas of the Rocky Mountain region, United States of America; Mallory, W.W. (Ed.), p 190-223. Rocky Mountain Assoc. Petrol. Geol.

McNeil, D.H. and Caldwell, W.G.E., 1981. Cretaceous rocks and their Foraminifera in the Manitoba escarpment. Geol. Assoc. Can., Spec. Paper 21

Price, Leon L., 1963. Lower Cretaceous rocks of southeastern Saskatchewan (Report, 12 figures, 3 tables, appendix); Department of Mines and Technical Surveys, Geological Survey of Canada, Paper 62-29, 44 p.

Simpson, F., 1975. Marine lithofacies and biofacies of the Colorado Croup (middle Albian to Santonian) in Saskatchewan. In: The Cretaceous System in the western interior of North America; Caldwell, W.G E. (Ed.), p. 553-537. Geol. Assoc. Can., Spec. Paper 13.