Type Locality:

Uplands west of Tate Lake adjacent to Mackenzie Mountains front, Fort Norman area (64 deg 30'N, 125 deg 32'W).

Distribution:

Underlies the broad upland region adjacent to Mackenzie Mountains front west of Mackenzie River and extends to the east side of Mackenzie River south of Fort Norman, and along Bracket River. It occurs as several isolated exposures on the east flank of Mackay Range and north of Keele River. At the type section where 295 m (968 ft) of strata occur, the base of base formation is not exposed. South of Fort Norman, on the east bank of Mackenzie River 64 m (210 ft) of strata are exposed. In the subsurface, the formation ranges from 85 to 277 m (279 to 909 ft) in thickness, however, Quaternary beds may be included within these intervals.

Locality Data:

Thickness(m): Minimum 85, Typical 295.

Lithology:

Mainly conglomerate, sandstone, tuff and low grade coal. The conglomerate is polymictic, comprised mainly of subrounded to rounded pebbles and cobbles of black chert, black siliceous shale, limestone, dolomite, quartzite, sandstone and tuff; they are locally moderately well-graded, and, in the lower parts of the succession where they are well indurated, form castellated cliffs and hoodoos. Where they are interstratified with sandstones they fill scour channels and occur as broad lenses. The sandstones are rusty brown weathering, fine- to medium-grained and well-sorted; they commonly display well developed trough cross-beds. The discrete layers of tuff weather pale yellow and are composed of poorly indurated, soft, sandy crystal tuff. At least one lens-like body of white to light grey, dense, finely vesicular glassy material occurs surrounded by baked, red, siliceous laminated shale. The low grade coals comprise mostly carbonized wood.

Relationship:

The contact with the underlying East Fork Fm is locally disconformable, however, available paleontological evidence suggests that the hiatus is short. It is the youngest bedrock exposed.

Other Citations:

Yorath and Cook, in press.

References:

Yorath, C.J. and Cook, D.G., 1981. Cretaceous and Tertiary stratigraphy and paleogeography, northern Interior Plains, District of Mackenzie; Geological Survey of Canada, Memoir 398, 76 p.