Unit Name: Pesika Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Llandovery - Wenlock (443.7 - 422.9 ma)
Age Justification: Graptolites indicate a middle Llandovery to Wenlock age (Cecile and Norford, 1979).
Province/Territory: British Columbia

Originator: Pyle and Barnes, 2000

Type Locality:
Pyle and Barnes (2000) designated the type section for the Pesika Formation at 57° 26'N, 124° 35'W.

Distribution:
The Pesika Formation is present in the Ware east-half map area, in the southern Kechika Trough (Pyle and Barnes, 2000).

Locality Data:
Thickness(m): Typical 230.

Lithology:
The Pesika Formation comprises mostly thin-bedded, grey, dolomitic limestone and dark grey, graptolitic shale with some thin beds of medium grey calcareous lime mudstone to grainstone (Pyle and Barnes, 2000).

Relationship:
The Pesika Formation is one of three formations of the Road River Group (Pyle and Barnes, 2000).The formation underlies the Kwadacha Formation and overlies the Ospika Formation (Pyle and Barnes, 2001).

History:
The Pesika Formation has been called informally the "Silurian Limestone" by Cecile and Norford (1979).

References:
Cecile, M.P. and Norford, B.S., 1979. Basin to platform transition, lower Paleozoic strata of Ware and Trutch map areas, northeastern British Columbia; in, Current Research, Part A, Geological Survey of Canada, Paper 79-1A, pp. 219-226.
Pyle, L.J. and Barnes, C.R. 2000. Upper Cambrian to Lower Silurian stratigraphic framework of platform-to-basin facies, northeast British Columbia. Bulletin of Canadian Petroleum Geology. 48:2. pp. 123-149.
Pyle, L.J. and Barnes, C.R. 2000. Upper Cambrian to Lower Silurian stratigraphic framework of platform-to-basin facies, northeast British Columbia; Bulletin of Canadian Petroleum Geology, v. 48, p. 123-149.

Source: GEOLOGICAL SURVEY OF CANADA
Contributor: M. T. Adamson
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 17 Jan 2009