Unit Name: Crystal Peak Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: older - Mississippian (4567.17 - 318.1 ma)
Age Justification: None.
Province/Territory: Yukon Territory

Originator: R.B. Campbell, 1967.

Type Locality:
Crystal Peak, the most prominent peak in the Wilkinson Range, Yukon (62 deg 54'N, 134 deg 30'W).

On Crystal Peak the formation is about 1,370 m (4,500 ft) but because of the massive character of the unit and structural uncertainty, this may be in error. The formation is found in the Mayo map-area (H.S. Bostock, 1947, map unit 10 in part) and in the Kalzas and Wilkinson ranges of the Glenlyon map-area and eastward.

Thick-bedded massive, generally light coloured, brown or medium to light grey to dark grey chert pebble and cobble conglomerate and breccia, minor amounts of quartzite. Chert is the most common class in the conglomerate with lesser amounts of white quartz and black argillite. Clasts are subangular to subrounded. Generally clasts are less than 1.5 cm (1 in). The matrix consists of subangular quartz commonly with overgrowths and chert grains. Cementation is variable with some fine-grained silica cement and argillaceous cement. In the vicinity of Earn Mountain the formation appears to contain thin interbeds of chert. Outcrops weather to dull brown and grey.

The formation (map unit 11 of R.B. Campbell, 1967) overlies with possible unconformity or disconformity map unit 10 by R.B. Campbell and conformably underlies the Kalzas Fm. Unit 7a and 7b (R.B. Campbell, 1954) is possibly equivalent to the Crystal Peak Fm.

Other Citations:
H.S. Bostock, 1947; R.B. Campbell, 1954, 1967.

Source: CSPG Lexicon of Canadian Stratigraphy, Volume 2, Yukon Territory and District of Mackenzie; L.V. Hills, E.V. Sangster and L.B. Suneby (editor)
Contributor: R.B. Campbell; L.V. Hills
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 25 Jun 2004