Geological map (1:50,000 scale) of eastern Ogilvie Mountains area, central Yukon (NTS 116A/10) including geological cross sections and mineral occurrences.

Geological map (1:50,000 scale) of southeastern Ogilvie Mountains area, central Yukon (NTS 116A/10) including geological cross sections and mineral occurrences.

The Hart River area (maps 116 A/10 and 11) of the southeastern Ogilvie Mountains is underlain by two varied and widespread successions which offer the most potential for discovery of sediment-hosted base metal deposits in the northern Canadian Cordillera. A 'shelf sequence', north of the Dawson fault, includes:: Middle Proterozoic Wernecke Supergroup; Middle and (?) Late Proterozoic Fifteenmile group; the Late Proterozoic Windermere Supergroup; Ordovician and Silurian carbonate; Ordovician to Devonian (?) Road River Group; Devonian Ogilvie Formation; and Devono-Mississippian Earn Group. The 'offshelf sequence' includes:: Late Proterozoic Hyland Group; Cambrian volcanic rocks; Lower Cambrian Vampire Formation equivalent; Cambrian Gull Lake Formation equivalent; Cambro-Ordovicain Rabbitkettle Formation equivalent; Ordovician and younger(?) Road River Group; Mississippian Keno Hill quartzite; and Devonian(?) to Jurassic(?) Lower Schist. The most promising exploration targets are:: 1) massive sulphide deposits associated with the Hart River volcanic rocks in the Gillespie Lake Group (upper part of the Wernecke Supergroup); 2) sedimentary copper deposits in the Fifteenmile Group; 3) 'Anvil-type' pyritic massive sulphide deposits in the transition zone between the Gull Lake and Rabbitkettle Formations; 4) 'Howard's Pass-type' zinc-lead deposits in previously unmapped black shales and chert of the Road River Group; 5) sulphide deposits associated with Cambrian, Ordovician(?) and Devonian(?) mafic volcanic and intrusive rocks; 6) covered areas at the base of the Lower Schist which may overlie the Earn Group, with potential for 'Macmillan Pass-type' zinc, lead, silver, barite deposits; 7) volcanogenic massive sulphide deposits associated with felsic volcanic rocks in the Keno Hill quartzite.

Geological map (1:50,000 scale) of the Ogilvie Mountains Breccias, Coal Creek Inlier, central Yukon (NTS 116B/11, 13, 14) including geological cross sections and mineral occurrences, as well as marginal notes on regional setting and decription and classification of Ogilvie Mountains Breccias.

The Irvine Lake and Gravel lake map-areas (NTS 105B/10,11) lie within the northern Omineca Belt, west of the Tintina-Northern Rocky Mountain Trench (NRMT) fault. The eastern part of the area is underlain by Proterozoic to early Paleozoic metasedimentary rocks of Cassiar terrane, a fragment of the North American miogeocline which has been displaced northward on the Tintina-NRTM fault. The western part of the area is underlain by basaltic metavolcanics, serpentinized ultramafic rocks, metagabbro, and cherty and calcareous metasediments of the Slide Mountain terrane. Unfoliated to weakly foliated granitic intrusives (Marker Lake and Cassiar batholiths and Cabin Creek and Gravel Creek stocks) occur throughout the area intruding both the Cassiar and Slide Mountain terranes. Slide Mountain and Cassiar terranes are juxtaposed by an east-verging thrust referred to in this area as the Zak fault. Southwest of Irvine Lake, the thrust places serpentine, basaltic meta-volcanics, and an undeformed dioritic intrusion onto a footwall consisting of the Proterozoic Tsaydiz Formation and older units. Northwest of Irvine Lake, near Shootamook Creek, the thrust places cherty metasediments of the allochthon onto marble and quartzite inferred to be lower Cambrian Rosella and Boya Formations, respectively. The northern end of the Cassiar batholith extends into the southwestern corner of Irvine Lake map area. Its northeastern contact with rocks of Slide Mountain terrane is a subvertical, northwest-southeast trending mylonite zone several tens of metres wide. Mesoscopic structures including S-C fabrics and shear bands prove dextral displacement parallel to a variably plunging, but commonly sub-horizontal stretching lineation. The mylonite zone lies along a pronounced topographic lineamnet which extends from the trace of the Cassiar fault south of the Alaska Highway northwestwardly into the Irvine Lake map-area rather than veering to the west as previously mapped. Mineral occurrences in this area are primarily near the contact of granitic intrusions and carbonate rocks. Carbonate rocks hosting the deposits belong to the upper Proterozoic Ingenika Group (Swannell, Tsaydiz and Espee formations) rather than the Lower Cambrian Atan Group as has been inferred for nearby deposits in the Rancheria district. Other, non-carbonate-hosted mineral occurrences include a porphyry Mo prospect and Ag, Pb, Zn veins.

Surficial geological map (1:50,000 scale) of Matson Creek and Ogilvie map areas, central Yukon (NTS 115N/9 and 115O/12) including marginal notes on surficial geology and geomorphology.

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