Preliminary observations on the geology of Tay Mountain Area (parts of NTS 105K/12 and 13, 105L/09 and 16), central Yukon

Regional mapping north and west of Faro is aimed at improving knowledge of the geologic history of the area and at elucidating the host stratigraphy and structures of both precious and base-metal occurrences. The southern part of the Tay Mountain area is underlain by metamorphosed lower Cambrian to Silurian Selwyn basin strata. These are thrust northward over Silurian to Triassic clastic, carbonate and volcanic rocks. The entire succession is intruded by mid-Cretaceous granitic rocks of the Tay River plutonic suite. The area is deformed by folding and north-verging thrust faults and by both east-west and north-south oriented normal faults. There is evidence that north-verging thrust faults are reactivated Devonian normal faults that formed in response to regional extension and controlled the deposition of the Earn Group. Selwyn basin strata, which are age-equivalent to the Anvil Mine host stratigraphy, crops out extensively south of the Twopete thrust fault. The end of a northwest-trending belt of silver-bearing occurrences is located at Mount Menzie. Folded chert in proximity to calcareous rocks and granitic intrusions are common features of the silver showings in the area.