Unit Name: Douro Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Late Silurian (422.9 - 416 ma)
Province/Territory: Nunavut
Originator: Thorsteinsson, 1963a.
Type Locality:
In a valley running through the Douro Range on the northeast side of Prince Alfred Bay, Devon Island (76 deg 21'N, 92 deg 50'W).
Distribution:
Occurs on southern Ellesmere, Devon and Cornwallis Islands, on Boo-thia Peninsula, and on Somerset, Prince of Wales, Stefansson, and Victoria Islands. Thickness varies from 95 m to 460 m.
Lithology:
Predominantly thin bedded, argillaceous limestone, usually mottled and nodular; also includes mottled dolomite, calcareous siltstone and calcareous shale. Stromatoporoidal limestone occurs in the uppermost portion on Prince of Wales Island.
Relationship:
Conformably overlies the Cape Storm and is conformably overlain by either the Barlow inlet or the Devon Island Formation. Laterally equivalent to part of the Cape Phillips Formation.
History:
Originally defined and mapped on Devon and Ellesmere Islands as a formation similar to Member A of the (then) Read Bay Formation. Thorsteinsson (in press) has raised the Read Bay to group status, with the Douro the lowest formation of the group.
Remark:
First Published: Geological Survey of Canada Maps 20, 21-1959.
Other Citations:
Thorsteinsson, 1963a, c; Greiner, 1963a; Smith 1976; Morrow and Kerr, 1977; Thorsteinsson, in press.
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: D.W. Morrow; A.F. Embry
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 29 Apr 2003