Marble, calc-silicate rock and pelitic layers of the Ram Creek assemblage surrounding the Dan Zn (± Cu-Pb-Ag) occurrence display ample evidence of a monocyclic structural evolution with three main events of progressive deformation (D1-D3). These events developed a tightly folded package of west-northwest-trending tectonites. Primary planar structures (S0) generally lie sub-parallel to two tectonic foliations (S1 and S2), which dip shallowly to steeply southwest. Inter-foliation slip (D3) resulted in a transverse, sub-vertical foliation (S3) that dips generally shallowly to moderately north. Cross-sections based on new mapping and fold analysis indicate that similar folds containing stratabound zinc-sulphide mineralization should be present south of the Dan occurrence, as part of regional north-northeast-verging folds or a thrust-fault-repeated succession.

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The layered rocks in this area originated as continental shelf sediments overlain by volcanic arc successions. Now called Yukon-Tanana terrane, they tectonically over-rode the western edge of ancient North America beginning in Middle Jurassic time. Three elements are present in the map area. The west half comprises the Big Salmon Complex; the east half is a separate, in part contemporaneous succession composed of the Dorsey Complex and Swift River Group. Unconformably overlying both these elements are less metamorphosed Klinkit Group and Triassic sediments that are here interpreted as overlap assemblages. The unexposed contact between Big Salmon Complex and Swift River Group is inferred to be an east-side-down normal fault.

Between the Cretaceous granitic rocks (Hake Batholith on the west; Cassiar Batholith to the east) are three belts of metamorphic rocks, collectively part of Yukon-Tanana terrane. These are remnants of oceanic and continental volcanic arcs, and marginal basin sediments of Early to mid-Paleozoic age. At the head of Borden Creek are thick carbonate and andesitic volcanic rocks correlated with Klinkit Group. The Ram Creek fault and Hidden Lake fault are not exposed but deduced to be steeply dipping brittle structures with northeastward thrust or transpressional offset, based upon more complete exposure to the southeast in 105B/3 map area. The former is likely of Cretaceous age; the latter was active between mid-Permian and Early Jurassic time.

Eight lithofacies types have been identified. These include: 1) Gms - massive, matrix support conglomerate; 2) Gm - massive or crudely bedded, clast supported conglomerate; 3) Sr - rippled sandstone; 4) Sp - planar crossbedded sandstone; 5) Sh - massive sandstone; 6) F1 - laminated sandstone, siltstone and mudstone; 7) Fsc - laminated or massive siltstone and mudstone; and 8) L - limestone. All lithofacies are present in the Sixtymile River area, but only lithofacies Sp, Sh and F1 were observed in the Grayling Creek area. The eight types are grouped into four assemblages and are interpreted as: 1) Scott type braided river deposits; 2) Donjek type braided river deposits; 3) South Saskatchewan type braided river deposits; and 4) lacustrine deposits. Lithofacies assemblages are arranged into at least ten fining-upward and thinning-upward megacycles reflecting a history of pulsed and rapid uplift in the source area.

The central Pelly Mountains in southeastern Yukon Territory consist of imbricate thrust sheets, which have undergone syn and post-thrusting deformation and metamorphism. The local geology is further complicated by intrusion of Upper Cretaceous batholiths, and by strike-slip faulting related to the Tintina Fault, a major northwest-trending transcurrent fault of uppermost Cretaceous or early Tertiary age. This faulting disrupts the northeast edge of the study area. Upper Devonian and Mississippian strata are present in at least two of the thrust sheets, but the Mississippian volcanic rocks occur in only one of them. The volcanic rocks consist of volcaniclastic material with minor interbedded flows, and were deposited in a submarine environment. Several coeval and cogenetic syenite and trachyte domes and small stocks are the remains of vent areas. Although the volcanic rocks are all highly altered and show evidence of widespread chemical mobility, trace element data indicate that the rocks are meta-luminous trachytes, most closely resembling peralkaline volcanics generated in extensional environments. This suggestion of a predominantly extensional tectonic setting in mid-Mississippian time in the Pelly Mountains is consistent with recent tectonic syntheses for the area. Stratabound and stratiform massive base metal sulphide deposits that occur within the Mississippian volcanic sequence are similar in many respects to the Kuroko-type volcanogenic massive sulphide deposits of Japan. The Pelly Mountains deposits, however, are among the first known occurrences in the world of Kuroko-type mineralization in a rift environment. A copy of this thesis is available at the EMR library – QE195 M67 1979. This thesis is available online at http://hdl.handle.net/2429/22257.

The Livingstone Creek area is underlain by metasedimentary and metaigneous rocks of Yukon-Tanana Terrane. It is intruded by at least five distinct suites of intrusive rocks of probable Mississippian to Late Cretaceous ages, at least three of which provide timing constraints on the development of tectonic foliations. Two phases of isoclinal folding, the development of a transposition foliation and late, northeast-vergent open folds characterize the ductile deformation in the area. Brittle-ductile dextral strike-slip deformation is localized along the north-trendingd Abbadie fault zone in the eastern part of the area. Bedrock in the area has potential for lode gold, copper-gold massive sulphide and nickel (platinum-group element?) mineralization along d'Abbadie Fault.

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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Bedrock mapping, during the summer of 2013, within the Granite Lake area was completed as part of the first year of a multi-year project to investigate the geological relationships in southwest Yukon. Several different tectonostratigraphic elements were identified including rocks of the Yukon-Tanana terrane, the Kluane schist, and the Bear Creek assemblage. These were tectonically juxtaposed into a northeast dipping structural stack with the Yukon-Tanana terrane occupying the highest structural level, followed by the Kluane schist and the Bear Creek assemblage. Two plutonic phases of probable mid-Cretaceous and Late Cretaceous age were identified to intrude the Kluane schist and the Yukon-Tanana terrane respectively. A large Paleocene aged batholithic intrusive suite, the Ruby Range suite, intrudes across all tectonic boundaries.Tectonic and stratigraphic relationships observed in southwest Yukon are strikingly similar to those found in southeast Alaska, near Juneau. These similarities increase the potential for Juneau gold-belt type mineralizing systems extending into southwest Yukon.