Subsurface geology of pre-Mesozoic strata, Great Bear River map area, District of Mackenzie

The geological sequence in the subsurface of Great Bear River map area begins with the Proterozoic Hornby Bay Group on the east, separated by the Fort Norman structure from the Mackenzie Mountains Supergroup on the west. Overlying these unconformably are the Cambrian rocks of Good Hope Basin and Keele Trough, which straddle Mahony Arch and include three formations: the Mount Clark; the Mount Cap (Members a to h); and the Saline River (Lower clastic, Salt, and Upper clastic members). The Upper clastic strata grade into the lower Paleozoic carbonates of the Ronning Group, comprising three formations: the Franklin Mountain (Cyclic, Rhythmic, Cherty and Upper dolomite members); the Mount Kindle (Basal, Lower dark and Upper pale members); and the Peel (undivided). Pre-Devonian erosion exposed Cambrian rocks over Keele Arch. Above this regional unconformity lie, in the south, the Delorme Group comprising the Tsetso and Camsell formations, overlain by the Fort Norman Formation, which was deposited penecontemporaneously with the Tatsieta Formation to the northwest. Overlying these are the laterally equivalent Arnica (dolomite) and Landry (limestone) formations, superseded in turn by the Middle Devonian Hume Formation (Headless Member, Middle and Upper members) and the Givetian Horn River Group consisting of the Hare Indian Formation (Bluefish Member, Grey shale and Black shale members), the Ramparts Formation (Siltstone lentil, Platform and Reef members), and the Canol Formation (Allochthonous limestone). The Upper Devonian Imperial Formation, including the youngest rock unit below the sub-Mesozoic unconformity, contains the localized Canyon Creek sandstone and Jungle Creek limestone member. The economic prospects of the Great Bear River map area include widespread hydrocarbon potential and the possibility of zinc, lead, and uranium oxide deposits.