Genesis and post-ore modification of the migmatized Carmacks Copper Cu-Au-Ag porphyry deposit, Yukon, Canada ...

• Main Author: Kovacs, Nikolett
• Format: Text
• Language: English
• Published: University of British Columbia 2019
• Subjects: Carmacks; Yukon
• Online Access: https://dx.doi.org/10.14288/1.0371119; https://doi.library.ubc.ca/10.14288/1.0371119

The Carmacks Copper and Minto Cu-Au deposits are hosted within northwest trending, variably metamorphosed, and deformed inliers engulfed by the Late Triassic to Early Jurassic Granite Mountain batholith (GMB). The origin of the deposits and their relationship to host rocks have been obscured by post-ore modification processes and their deposit genesis is controversial. Detailed study of the Carmacks Copper deposit indicates that it is hosted by Late Triassic (210.1 ± 5.3 Ma, U-Pb zircon) quartz-plagioclase-biotite schist and amphibolite, which form part of the Late Triassic Stikinia arc (Povoas Formation, Lewes River Group). The metamorphic rocks preserve an early northwest trending, steeply dipping, penetrative foliation (S₁). Hypogene copper mineralization occurs as S₁ parallel chalcopyrite stringers. The minimum age of mineralization is 212.5 ± 1.0 Ma, which is the ¹⁸⁷Re/¹⁸⁷Os age obtained for molybdenite inherited from a mineralized protolith. The ca. 198 Ma Granite Mountain batholith intrudes the ...