Type Locality:

Cliff, 0.8 km (0.5 mi) west of the marshy shore of Moose Lake, Manitoba at 54 deg 03'N (approximately Sec. 26, Twp. 58, Rge. 20WPM). Suggested reference core hole and outcrop section is at Manitoba Mineral Resources Division core hole M-6-79, in Lsd. 6, Sec. 32, Twp. 57, Rge. 12WPM, between 3.4 and 10.5 m (?) (11.2 and 34.4 ? ft), and at the William River microwave tower.

Distribution:

Stearn reported a thickness of 4 m (13 ft) for the upper unit and 4.6 m (15 ft) for the lower unit where the two units can be distinguished. The name has been applied only to the Silurian outcrop belt of southwestern Manitoba, primarily to the area north of Grand Rapids. Extensive "new" or newly accessible outcrops, not reported by Stearn or Baillie, occur for 91.7 km (57 mi) north of Grand Rapids and generally east of Highway 6, where they form a prominent scarp at the erosional edge of the Silurian strata. From 91.7 km (57 mi) the scarp bends west and becomes highly irregular and dissected, extending from north of William Lake to Moose Lake and Atikameg Lake. Extensive "new" exposures also occur as shore cliffs on Buffalo, Little Limestone, William and Talbot Lakes. The most southerly reported outcrops are on the south shore of Lake St. Martin and west of Fisher Branch.

Lithology:

The Moose Lake Dolomite consists of two units. The lower is a thin-bedded, aphanitic, in part highly fossiliferous dolomite showing only rare evidence of algal content. The upper dolomite is very fine-grained to aphanitic, medium-bedded, almost totally stromatolitic, with bedding planes rising into small, closely packed domes; interbeds of dolomite breccia consisting of thin algal slabs are common throughout.

Relationship:

The unit overlies conformably and gradationally the fragmental dolomites of the Inwood Formation. Contact with the overlying brown, massive, vuggy Atikameg Dolomite ranges from gradational to sharp, and may be locally disconformable. In the subsurface equivalent strata comprise a part of the lower Brandon Formation (Interlake Group) of King, in Cowan (1971), or a part of the lower Interlake Group of Porter and Fuller, (1959).

Other Citations:

Baillie, 1951; King, in Cowan, 1971; Porter and Fuller, 1959; Stearn, 1956.