Geology of the Aishihik Lake and Hopkins Lake Map Areas (115 H/6,7), Southwestern Yukon

Paleozoic and older metamorphic rocks in the Aishihik Lake and Hopkins Lake map areas (115 H/6 and 7) comprise the Aishihik Metamorphic Suite (AMS) and form a north-northwest-trending panel of rock that dips regionally to the east. The suite is divisible into a lower feldspathic quartz micaschist and marble package with a minor component of metaigneous rock and an upper package that includes black and brown quartzite, marble, metabasite and orthogneiss. Igneous rocks of three plutonic suites and one volcanic suite are present in the study area. Foliated hornblende granodiorite of the Aishihik Batholith, part of the Aishihik Plutonic Suite (APS), intruded in the Early Jurassic resulting in upper amphibolite grade metamorphism of the AMS. Relatively mafic APS plutonism evolved rapidly into more leucocratic quartz monzonite of the Early to Middle Jurassic Long Lake Plutonic Suite (LLPS). The Ruby Range Plutonic Suite (RRPS), including the Ruby Range Batholith and isolated stocks and tear-shaped plugs north of the batholith, intruded in the Late Cretaceous to Early Tertiary resulting in contact metamorphism and potassic metasomatism of the AMS. Sub-volcanic dykes and plugs that…

Publisher

Government of Yukon

Resources

3

Catalogue metadata updated

2026-08-26