The Mount M'Clintock map area, northeast of Whitehorse, is dominated by Middle Triassic to Jurassic sedimentary and volcanic strata of Stikinia with small portions of the Cache Creek and Yukon-Tanana Terranes. These assemblages were deformed prior to the mid-Cretaceous intrusion of three plutonic suites and the deposition of two suites of volcanic rocks. Sedimentary rocks previously mapped as undifferentiated Lewes River and Laberge Group strata are separated into their respectve groups and further sub-divided into several members. Lewes River Group rocks form three units that are Carnian and older, Norian, and Upper Norian in age and are represented by siliceous siltstone and calcareous sandstone, conglomerate and limestone respectively. Laberge Group strata are divided according to lithology and dominated by siltstone-sandstone couplets and massive siltstone with lesser conglomerate and volcanogenic sandstone. Volcanic rocks previously mapped as Hutshi Group are divided into the dominantly mafic and submarine, MiddleTriassic Joe Mountain volcanic complex (JMVC) and the dominantly felsic and sub-aerial Mount Byng volcanic complex (BCVC). The volcanic and sedimentary rocks generally increase in age from Middle Triassic to Jurassic from west to east across the map area. Plutons cutting these strata belong to the M'Clintock Lakes (120 Ma), the Whitehorse (115 Ma), and the Mount McIntyre (109 Ma) plutonic suites. The predominantly felsic fragmental rocks of the BCVC are genetically associated with the Byng Creek pluton of the Mount McIntyre plutonic suite. The BCVC is nested into the country rocks and its eastern margin and is preserved as the rim of a tilted caldera. Strata of the Laberge and Lewes River groups are folded throughout. Wavelengths are on the order of approximately 1-2 km, but are much tigter in black siltstone units and adjacent to northwest-trending faults. Faults are ubiquitous throughout the map area and form three sets. North-trending faults are the most common. They are spaced a few kilometres from each other and dictate the physiography and drainage of the region. Northwest-trending faults, in the northeastern corner of the map area control the Teslin River valley and juxtapose Yukon-Tanana rocks with Stikinia. Older faults are dominantly east-trending but are terminated or reactivated by younger faults. Copper (gold-molybdenum-tungsten) skarns and gold-bearing quartz veins are the two mineral deposit types most likely to be discovered in the map area. The source of the placer gold in Sheldon Creek is unknown but may be related to gold veins in the JMVC, BCVC, Sheldon Creek volcanics or the surrounding sedimentary rocks. Hydrothermal activity in the JMVC is characterized by orange weathering alteration, breccias, and carbonate veins. Cache Creek rocks in the southern part of the map area are targets for listwaenite associated gold veins.

Surficial geological map (1:50,000 scale) of Mount Haldane area, central Yukon (NTS 105M/13) including marginal notes on physiography, glacial history, placer gold potential and terrain hazards.

not_specified

Geological map (1:50,000 scale) of Mount M'Clintock map area, southern Yukon (NTS 105D/16) including geological cross sections and mineral occurrences.

Preliminary geological map (1:50,000 scale) of Mount M'Clintock area, southern Yukon (NTS 105D/16) including geological cross sections and mineral occurrences.

not_specified

The Apex Mountain map area is located in the central part of the Dawson Range. Apex Mountain is the highest summit reaching an elevation of 2000 m. Upland topography changes from rounded summits throughout much of the southern half of the map area to more rugged terrain in the north part of the map area where the Dawson Range divide is located. Most of the map area is drained by the Klotassin River and Somme Creek. A cluster of streams near Apex Mountain drain northward into the Selwyn River or Hayes Creek.

The Mount Brenner stock has intruded folded sedimentary and meta sedimentary rock that lie 40 miles northeast of Dawson City, Yukon. The stock consists of four major concentric zones: (l) an outer zone of fine to medium-grained augite-biotite monzonite; (2) a zone of very coarse-grained monzonite porphyry; (3) an intermediate zone of porphyritic horn blende monzonite; and (4) a central zone of coarse-grained pink quartz monzonite porphyry. Except for the outer zone, all rock types are porphyritic and the alignment of feldspar phenocrysts gives the rocks a primary flow structure which conforms to steeply outward dipping gradational internal contacts. All external contacts are sharp. The regional structural trend is modified in the vicinity of the stock so that beds are generally conformable with the intrusive contact. From structural evidence, it is concluded that at the present level of erosion, the stock was emplaced by forceful injection. The different rock zones of the stock can be accounted for by differentiation of an augite-biotite monzonite magma by a combination of crystal fractionation, volatile and alkali diffusion, and multiple intrusion. This thesis is available online at https://open.library.ubc.ca/cIRcle/collections/ubctheses/831/items/1.0053527. A copy of this thesis is available from the EMR library – QE195 L35.

A preliminary geological map (1:25,000 scale) of Mount Skukum volcanic complex, southern Yukon (NTS 105D/2,3,4,5), including one cross section.