Named as a unit (1 of 9) in the "Lower volcanic series" for the White Eagle mine in sec. 34, T 19 S, R 9 W, northern Cooks Range, Grant Co., NM in the Basin-and-Range province. No type locality designated. Mapped (geologic map) in the Cooks Range and to south of range in secs. 3 and 10, T 20 S, R 9 W, Luna Co., MN in the Basin-and-Range province. Forms dikes in Precambrian granite as much as 1 mile long and 50 ft wide, and sills 56 ft thick. Flows cap Precambrian granite gneiss. The rhyolite is aphanitic, cream-colored, flow banded and flow folded with slickensides on surfaces of flow bands. Contains sparse phenocrysts of quartz and feldspar. Rounded inclusions of Precambrian granite gneiss in dikes and in bottom of flows. Zones of white spherulites as much as 3 ft thick mark the margins of most dikes and sills. Tertiary age assigned.

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