Type Locality:

One and one half miles north of Rockslide Pass in west-central Wrigley Lake map-area, (63°21'N; 127°32'W).

Distribution:

The formation ranges from 248-500 m (815-1,640 ft). It is widely exposed on the Redstone Plateau in the southwestern part of the Wrigley map-area and in the Backbone Ranges in the northwesternmost Glacier Lake map-area.

Locality Data:

Thickness(m): Minimum 248, Maximum 500.

Lithology:

Recessive platy, nodular black to orange buff weathering, dark grey, fine-grained, argil-aceous limestone and calcareous siltstone. Argillaceous parts produce a sooty talus. The lower part of the formation consists of 61 m (200 ft) or more of silty or argillaceous strata. Up to 152 m (500 ft) of sooty black weathering calcareous siltstone argillaceous limestone and shale make up the middle part of the formation and the upper unit consist of up to 61 m (200 ft) of thin-bedded platy limestones. In the easternmost parts of the Wrigley map area the lower members consist of about 61 m (200 ft) of green, brown and red weathering shales. These are overlain by fine-grained thin-bedded, locally oolitic limestone which weathers to shades of brown or grey mottled wine or pink, (resemble the Avalanche Formation).

Relationship:

The Rockslide Formation disconformably overlies an unnamed argillaceous unit which overlies the Sekwi Formation and is unconformably overlain by the Avalanche Formation. Gordey (1979) diagramatically illustrates the Rockslide as unconformably overlying the Sekwi and to be unconformably overlain by the Sunblood-Broken Skull formations (undivided).

References:

Gabrielse, H., Blusson, S.L., and Roddick, J.A., 1973. Geology of the Flat River, Glacier Lake and Wrigley Lake map-areas, District of Mackenzie and Yukon Territory; Geological Survey of Canada, Memoir 366 (Parts I and II), 421 p.

Gordey, S.P., 1979. Stratigraphy of the southeastern Selwyn Basin in the Summit Lake area, Yukon and Northwest Territories; in, Current Research, Part A; Geological Survey of Canada, Paper 79-1A, pp.13-16.