Unit Name: Hart River Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: late Visean, V3 - Moscovian (332 - 307.2 ma)
Age Justification: Brachiopods, ammonoids and Foraminifera.
Province/Territory: Yukon Territory

Originator: Bamber and Waterhouse, 1971.

Type Locality:
North bank of the Peel River approximately 14.5 km (9 mi) east of its confluence with the Hart River (65 deg 53'N, 136 deg 05'30"W), Yukon Territory.

It is 242 m (794 ft) thick at the type section, 418 m (1,370 ft) in the Ogilvie Mountains, approximately 314 m (1,030 ft) in the Keele Range and from 305 to 366 m (1,000 to 1,200 ft) on the headwaters of the Eagle River. It is absent beneath the sub-Permian unconformity near the confluence of the Driftwood and Porcupine rivers. It outcrops on the west flank of the Richardson Mountains to the south along the Peel, Hart and Ogilvie rivers and to the west in the Northern Ogilvie Mountains (Bassett and Stout, 1967; Norford, 1964; A.W. Norris, 1967a) and is widespread in the subsurface of the Eagle Plain.

Recessive light and dark brownish-grey weathering, laminated, silty, skeletal-micritic limestone and silty, calcareous dolomite and chert. The lowermost 147 m (483 ft) consists of micritic skeletal limestone and microcrystalline dolomite whereas the upper 95 m (311 ft) is recessive with some dark grey, silty dolomitic shale outcrops. H.L. Martin (1972) subdivided the Hart River Fm in the subsurface of the Eagle Basin Y.T. into four members listed in ascending order: 1) Birch, 0-480 m (0-1,576 ft), conglomeratic sandstone, siliceous shale and siliceous limestone; 2) Canoe River, 0-682 m (0-2,237 ft), siliceous shale and siliceous micritic limestone; 3) Chance Sandstone, 0-310 m (0-1,016 ft), conglomeratic sandstone with siliceous and calcareous cement; and 4) unnamed unit, carbonates.

It is underlain throughout the area by unnamed recessive dark grey shale, Unit 1 of Bamber and Waterhouse (1971) and is conformably overlain by the Ettrain Fm in the Ogilvie Mountains and by Unit 2 in the Eagle Plain area. It is equivalent to the upper part of the Calico Bluff Fm (Northern Ogilvie Mountains) of Nelson (1961) and correlates to the Alapah Fm of the British and Barn mountains, and the Calico Bluff Fm of east-central Alaska of Brabb (1969).

Other Citations:
Bamber, 1972; Bamber and Waterhouse, 1971; Bassett and Stout, 1967; Brabb, 1969; Graham, 1973; H.L. Martin, 1972; Nassichuk and Bamber, 1978; Nelson, 1961; Norford, 1964; A.W. Norris, 1967a.

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: L.V. Hills; E.W. Bamber
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 29 Apr 2003