Sophia Lake Formation

Unit Name: Sophia Lake Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Early Devonian (416 - 397.5 ma)
Province/Territory: Nunavut

Originator: Thorsteinsson and Uyeno, 1980.

Type Locality:

North side of Read Bay, central east coast of Cornwallis Island.

Distribution:

Occurs along the central east coast of Cornwallis Island, west coast of Devon Island, and east coast of Baillie Hamilton Island; about 560 m thick on Cornwallis, at least 980 m on Baillie Hamilton, and about 300 m on Devon Island.

Locality Data:

Thickness(m): Minimum 300.

Lithology:

Mainly planar-bedded limestone with lesser amounts of dolomite, siltstone, sandstone and shale. The limestone is cryptocrystalline to finely crystalline, thin bedded and often argillaceous, silty or sandy. Regional variations include units of gypsum and gypsiferous shale on Devon Island and thick bedded limestone with corals and stromatoporoids on Baillie Hamilton Island.

Relationship:

Conformably overlies the Barlow Inlet and is conformably overlain by the Snowblind Bay Formation.

History:

Originally designated as Member D of the Read Bay Formation (Thorsteinsson, 1958). Thorsteinsson (1974) raised the Read Bay to group status with the Sophia Lake as the uppermost formation within the group.

Other Citations:

Thorsteinsson, 1958, in press.

References:

Thorsteinsson, R. and Uyeno, T.T., 1980. Stratigraphy and conodonts of Upper Silurian and Lower Devonian rocks in the environs of the Boothia Uplift, Canadian Arctic Archipelago; in, Contributions to stratigraphy, Geological Survey of Canada, Bulletin 292, p. 1-38.

Thorsteinsson, R., 1958. Cornwallis and Little Cornwallis Islands, District of Franklin, Northwest Territories: Geological Survey of Canada, Memoir 294 (1959), 134 p.

Source: CSPG Lexicon of Canadian Stratigraphy, Volume 1, Arctic Archigelage (District of Franklin); R.L. Christie, A.F. Embry, G.A. Van Dyck (editor)
Contributor: A.F. Embry
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 14 Apr 2009