The Talbot Creek map area straddles the Ruby and Nisling ranges. Broad treeless uplands dominate the landscape with summits reaching 2100 m above sea level in the Ruby Range and 1800 m above sea level in the Nisling Range. Upland surfaces are covered with weathered bedrock colluvium and sporadically distributed till deposits from former alpine glaciers and ice sheets. Upland surficial deposits are affected by active periglacial processes such as cryoturbation, nivation and solifluction.

The Granite Creek map area includes the southwestern section of the Gustavus Range. This area hosts summits approximately 2000 m in elevation. Granite and Albert creeks drain into Roop Lakes, through the wide, u-shaped lower Granite Creek valley. Keystone Creek flows in a narrow, bedrock-controlled valley. Lower Granite creek flows through the middle of the valley, depositing modern fluvial gravel and a blanket of organic material on the floodplain. Till from four alpine sources, as well as from the Cordilleran Ice Sheet (CIS), blanket the lower valley and intermix with glaciolacustrine sand and silt. Glaciolacustrine sediment can also be found capping moraines, and on valley walls above lateral moraines deposited when the CIS advanced up lower Granite Creek valley. Glaciofluvial gravel forms a proglacial fan where the former Granite Creek alpine glacier terminated and meltwater channels mark most former ice margins of the CIS. Till from the most recent glaciation is found in alpine glacier and Cordilleran Ice Sheet moraines, as well as in cirque valleys as blankets and veneers where preserved. Loess forms blankets on most gentle slopes, which allows for its preservation. Colluvium veneers, blankets, and fans form below steep slopes with active rockfall. Bedrock outcrops along steep cirque headwalls and in cirque valleys, as well as in Keystone Creek where fluvial downcutting processes are active. Stone stripes formed by frost heaving are found on gentle slopes. Flat upland surfaces host weathered bedrock and mud boils.

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.

The Kiyera Lake map area straddles the northwestern extent of the Nisling Range. Broad treeless uplands dominate the landscape with summits reaching above 1800 m above sea level. Upland surfaces are characterized by weathered bedrock colluvium, tors and sporadically distributed till deposits from former alpine glaciers in cirques. Upland surficial materials are affected by active periglacial processes such as cryoturbation, nivation and solifluction.

Geology including geological cross sections and mineral occurrences.

Geological map (1:50,000 scale) of "Dolores Creek" area, Wernecke Mountains, central Yukon (NTS 106C/14) including geological cross-sections and mineral occurrences.

The central Yukon Territory has a number of favourable placer deposit settings due to its unique history of multiple glaciations, active stream sedimentation in association with proglacial outwash settings and terrain which has remained unglaciated. Placer gold was found along the Stewart River on point bars in 1884 prior to the discovery of gold in the Klondike area. This was the first indication that the Yukon Territory contained important economic concentrations of placer gold. This study is concerned with the late Tertiary and Quaternary geology in the Lower Stewart River and adjacent Yukon River above Dawson. Previous systematic surficial geological mapping and testing for placer gold on the high-level terraces along these rivers has been limited. This report describes the sedimentology and stratigraphy of key gravelly exposures in this area because similar high-level terraces in the Fortymile River drainage in Alaska had been mined for gold for many years. Work of this type also provides information on the physical characteristics of gravelly deposits (e.g., grain size distribution) which may assist regulatory decisions on placer mining in the lower Stewart and Yukon drainages. Accompanying this report are two 1:50 000-scale surficial geology maps including marginal notes (Garner Creek, NTS 115O/13 and Matson Creek and Ogilvie NTS 115N/9 (east half) and 115O/12), as well as one 1:250 000-scale topographic map (Stewart River - NTS 115N/O) including field study site locations, heavy mineral sample sites and hardrock mineral occurrences.

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