Includes a geological cross section, mineral occurrences and isotopic age dates.

The core of Glenlyon and northeastern Carmacks map areas is underlain by a northwest-trending belt of metasedimentary, metavolcanic and (meta)plutonic rocks of the Yukon-Tanana Terrane. It includes two successions of Carboniferous arc volcanic rocks, associated plutonic suites of Mississippian age, Devonian-Mississippian metaclastic rocks, and their basement complex. To the southwest, Yukon-Tanana Terrane is juxtaposed with the Semenof block a belt of mafic metavolcanic rocks of uncertain terrane affinity along the Needlerock and Big Salmon faults. To the northeast, the Tummel fault zone delineates the contact between Yukon-Tanana and Cassiar terranes. The narrow belt of chert, argillite and greenstone which occurs within the Tummel fault zone probably correlates with the Slide Mountain Terrane. The area is intruded by Early Jurassic and Cretaceous plutons and is dissected by a series of late faults, which results in approximately 56 km of dextral offset of the Yukon-Tanana Terrane.

The Finlayson Lake fault zone forms the boundary between autochthonous North American rocks and rocks of the innermost accreted Slide Mountain and Yukon-Tanana terranes in southeastern Yukon. Geological mapping at 1::50 000 scale in a well exposed area of the Campbell Range, southeastern Yukon, was undertaken to examine the kinematics of the Finlayson Lake fault zone and rock types of the Slide Mountain terrane. Five units were identified: (1) chloritic schist and phyllite, (2) laminated metachert and carbonaceous black slate, (3) tan weathering metachert and maroon siliceous and argillaceous metasiltstone, (4) greenstone and associated breccia, gabbro, metagreywacke, metachert and maroon metasiltstone and (5) serpentinite. Unit 2 is structurally interleaved with submap-scale bodies or layers of serpentinite, hornblende-plagioclase porphyry, plagioclase-potassium fledspar porphyry, quartz-eye muscovite-chlorite phyllite or schist, chloritic schist and minor grey, calcareous metacarbonate. Serpentinite is also exposed in unit 4 and as small slivers along the thrust contact between units 3 and 4. Lithologically, units 4 and 5 are similar to the upper division of the Slide Mountain terrane in east-central and north-central British Columbia. Unit 2 has similarities with the lowest division of the Sylvester allochthon and is tentatively correlated with the Slide Mountain terrane. Maroon metasiltstone in unit 3 is indistinguishable lithologically from metasiltstone in the overlying greenstone unit suggesting that the eastern thrust fault juxxtaposes parts of the same depositional sequence, ie. The Slide Mountain terrane. Regional correlation of unit 1 is unclear. Unit 2 is inferred to be bounded to the east and west by northwest-striking faults and to the south, by an east-striking, steeply dipping, normal (north-side down) fault. The northern boundary of unit 2 is unconstrained. Greenstone (unit 4) is thrust towards the southwest over unit 1 in the western part of the map area along a northwest-striking, gently northeast-dipping thrust fault. In the eastern part of the map area, greenstone is thrust towards the northeast over unit 3 along a northwest-striking, moderately southwest-dipping thrust fault. Outcrop data and topographic patterns suggest that the eastern thrust fault is truncated by a northwest-striking, steeply dipping fault and that the normal fault truncates the westernmost northwest-striking fault. The northwest-striking faults are poorly exposed and their kinematics have yet to be determined. However, if they are steep faults, they are likely dextral strike-slip faults. Field data indicate that the Finlayson Lake fault zone consists of diverging thrust faults and subparallel strike-slip(?) faults. These structures are consistent with the interpretation of the Finlayson Lake fault zone as a transpressive fault zone. More constraints on the relative timing of faulting and the kinematics of the steep faults are required to test this hypothesis,

Mapping was carried out in the summer of 2018 by Rosie Cobbett and Halley Keevil for areas north of the Tintina fault; additional geological data provided by G. Jilson. Geology south of the Tintina fault is from YGS Open File 2002-9. Two areas north of the Tintina fault are extensively thermally and hydrothermally altered. The interpretation of fault traces through areas of poor rock exposure was guided by a Yukon wide geophysical survey of magnetic data.

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This map accompanies paper: Johnston, S.T. and Shives, R.B.K., 1995. Interpretation of an airborne multiparameter geophysical survey of the northern Dawson Range, central Yukon: A progress report. In: Yukon Exploration and Geology, 1994. Exploration and Geological Services Division, Yukon, Indian and Northern Affairs Canada, p. 105-111.

Surficial geological mapping in the central Kluane Ranges was undertaken to better understand the distribution and character of surficial materials. Upland surficial materials in the area are dominated by near-source bedrock derivatives. Valley bottom settings, including Shakwak trench and Duke River valley, are characterized by broad open valleys with thick deposits of Quaternary sediment. Permafrost is discontinuous in the study area and its character is affected by slope and aspect, topography and material texture. Mass wasting processes in the study area include rock fall and avalanches, debris flows and avalanches and active layer detachment slides. The distribution and character of surficial materials has significance for soil geochemical sampling programs and infrastructure and implications for mineral exploration and developments are addressed.

Geological map (1:50,000 scale) of the East Klondike area, central Yukon (NTS 115O/9,10,11,14,15,16 and 116B/2) including marginal notes on geologic history, economic geology and mineral occurrences.