In southern central Yukon Territory, Canada, a northwest-trending 267 Ma ophiolitic assemblage defines the Tummel fault zone (TFZ), which juxtaposes Paleozoic miogeoclinal strata of Cassiar terrane with metavolcanic and metasedimentary rocks of Yukon-Tanana terrane. Basalt, greenstone, and chert occur in the TFZ and are correlated with Slide Mountain terrane. Northeast of the TFZ, pelitic and semipelitic rocks of the Kechika Group are overlain by carbonate of the Askin Group in Cassiar terrane. Southwest of the TFZ, Yukon-Tanana terrane comprises Devonian-Mississippian quartzofeldspathic basement (the Snowcap Complex) overlain by Mississippian clastic and arc-derived rocks of the Drury, Pelmac, and Little Salmon formations. The ca. 105 Ma Glenlyon Batholith and its satellite plutons intrude Cassiar terrane and the TFZ, imposing a contact metamorphic aureole that overprints earlier metamorphic features in rocks of Cassiar and Yukon-Tanana terranes and the TFZ, and indicates pre-105 Ma juxtaposition of these three tectonic assemblages.

In southern central Yukon Territory, Canada, a northwest-trending 267 Ma ophiolitic assemblage defines the Tummel fault zone (TFZ), which juxtaposes Paleozoic miogeoclinal strata of Cassiar terrane with metavolcanic and metasedimentary rocks of Yukon-Tanana terrane. Basalt, greenstone, and chert occur in the TFZ and are correlated with Slide Mountain terrane. Northeast of the TFZ, pelitic and semipelitic rocks of the Kechika Group are overlain by carbonate of the Askin Group in Cassiar terrane. Southwest of the TFZ, Yukon-Tanana terrane comprises Devonian-Mississippian quartzofeldspathic basement (the Snowcap Complex) overlain by Mississippian clastic and arc-derived rocks of the Drury, Pelmac, and Little Salmon formations. The ca. 105 Ma Glenlyon Batholith and its satellite plutons intrude Cassiar terrane and the TFZ, imposing a contact metamorphic aureole that overprints earlier metamorphic features in rocks of Cassiar and Yukon-Tanana terranes and the TFZ, and indicates pre-105 Ma juxtaposition of these three tectonic assemblages.