The southern Nash Creek area is located along the northern boundary of the Selwyn basin, and is underlain mainly by the Ediacaran–Cambrian Hyland Group, the Devonian–Mississippian Earn Group and the Mississippian Tsichu Group. Several Au and polymetallic mineral deposits are hosted by the Hyland Group and Paleozoic platformal carbonate rocks in the surrounding region. The southern Nash Creek area is bordered by regional-scale, southeast-striking thrust faults, which include the Dawson thrust to the northeast and the Robert Service thrust to the southwest. Based on stratigraphic relationships identified during 1:50 000-scale bedrock mapping, Hyland Group rocks in the area are considered to belong to the Cryogenian–Ediacaran Yusezyu Formation, the Ediacaran Algae Formation and the Ediacaran–Terreneuvian Narchilla Formation. Earn Group rocks include mainly shale and lesser amounts of interbedded dolostone, sandstone and shale. Tsichu Group rocks mostly comprise quartzite. The Yusezyu and Narchilla formations host (Paleozoic?) gabbro sills, and the Earn and Tsichu groups host gabbro sills that are considered to belong to the Triassic Galena suite. Rocks in the southern Nash Creek area exhibit a northeast-to-southwest dipping foliation that is axial planar to southeast-trending folds.

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Weasel Lake map area (105G/13) is located at the northwestern end of the Finlayson Lake belt (displaced Yukon-Tanana Terrane) and extends northward into ancient North American rocks. Several volcanogenic massive sulphide deposits including: Wolverine, Kudz Ze Kayah, Fyre Lake and the Ice, have been discovered in this part of Yukon-Tanana Terrane, which makes this region one of the most prospective areas of Yukon. Limited outcrop exposure, due to widespread Quaternary cover, has made prospecting challenging in many parts of this terrane, including Weasel Lake map area. Surficial geological mapping and till geochemical sampling was conducted in the map area to better understand its mineral potential. Ice-flow over the area trended at approximately 305° and remained topographically unobstructed through the last glacial maximum. As a result, basal till was deposited across most of the map area. Late glacial deposition of glaciofluvial sediment and meltout till was more common in the northeast part of the map and along the Pelly River. Results of the till geochemical sampling program highlighted anomalies in base-metal elements, platinum/palladium indicators, as well as a gold indicator suite, suggestive of epithermal mineralization.

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Paleozoic rocks of the Pelly Mountains, central Yukon, preserve greater than 150 m.y. of sedimentation, magmatism and base-metal mineralization. To identify secular trends in regional tectonics and metallogeny, a multi-year project on the stratigraphy of the Pelly Mountains in the Quiet Lake (105F) and Finlayson Lake (105G) map areas was initiated. Field studies during summer 2015 focused on two stratigraphic intervals: (1) mafic volcanic, volcaniclastic and clastic rock successions assigned to the Cambrian-Ordovician Cloutier and Groundhog formations (Kechika group); and (2) felsic volcanic, volcaniclastic and clastic rock successions assigned to the Devonian-Mississippian Black Slate and Felsic Volcanic formations (Seagull group). Cambrian-Ordovician strata were deposited in a marine environment characterized by episodic mafic volcanism and extensional tectonism. Devonian-Mississippian strata record the transition from an extensional turbidite basin to a metalliferous volcanic rift basin, and resemble key rock assemblages of the Selwyn basin (Earn Group) and Yukon-Tanana terrane (Grass Lakes and Wolverine Lake groups).

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The region east of Lake Laberge in south-central Yukon was mapped from 2015–2018 as part of a 1:50¿000 scale bedrock mapping program conducted by the Yukon Geological Survey. The area encompasses the map sheets of Teslin Mountain (NTS 105E/2), and parts of Lake Laberge (105E/3) and Lower Laberge (105E/6). A 1:50¿000 scale bedrock geology map complements this report; Geoscience Map 2019-1 by E. Bordet.

West Lake map area (105N/9) is underlain by three fault-bounded structural blocks containing tectonically thickened (Late Proterozoic to Mississippian) Selwyn Basin strata. Northeast of the West Lake Fault tightly folded Hyland Group is structurally overlain by Road River Group. Between the West Lake and Wilson Range faults Hyland Group is thrust over Earn Group. In this block the variety of rocks preserved beneath the sub-Earn Group unconformity is greater than surrounding areas. Southwest of the Wilson Range Fault is a tectonically thickened, homoclinal succession of Road River and Earn groups. Silver-bearing quartz veins above and below a thrust fault were mined at the Plata occurrence. Anomalously high Ag, Zn and Pb concentrations in stream sediments result from black shale of the Earn Group exposed in three belts across the map area.