Unit is named the Summit-Frazer Trondhjemitic Gneiss. Includes premetamorphic basement gneisses in the western part of the Okanogan Range, WA. Main phase includes 95 percent of the batholith and consists of trondhjemitic orthogneiss with metamorphic textures resulting from Mesozoic metamorphism. Older inclusion phase along the eastern margin contains altered metasedimentary and xenoliths of igneous rocks. Coyote Ridge quartz dioritic gneiss phase is a border phase in the southwestern part of the area. Represents a premetamorphic granitic basement mobilized as a gneiss dome during Mesozoic regional metamorphism. Intrudes the older Leecher Metamorphics on the west side; is intruded by the early Mesozoic Leader Mountain Granodioritic Gneiss and the Late Cretaceous Conconully Granodiorite (new). Age is pre-Mississippian. (B1565)

Source: GNU records (USGS DDS-6; Menlo GNULEX).