Type locality designated as northeast slope of Bloody Mountain, along jeep trail leading to prospect high on north slope, Mount Morrison 15' quad, Mono Co, CA. Crops out in nearly continuous layer from north end of ridge separating Laurel and Sherwin Creeks, southeastward 8.5 mi to east slope of Red and White Mountain 1.5 mi south of quad boundary in Mount Abbot quad. Shown on geologic map as part of Bloody Mountain block. Consists of dense dark-gray pyritic siliceous hornfels with scour and fill and intraformational conglomerate near base. Thickness is about 3000 ft near type but intrusive granodiorite has cut out upper part. Overlies Lake Dorothy hornfels (new) with sharp to gradational contact; disconformably underlies metavolcanic rocks of Mesozoic age. Fossils identified by Mackenzie Gordon, Jr. (written commun., 1958) suggest possible Permian(?) age.

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