Named exposures along mountain front between Cressman's Gulch and Van Bibber Creek, Ralston Buttes quad, Jefferson Co, CO in the Southern Rocky Mountain region. Type area designated as NW/14 sec 17 and SW1/4 sec 8, T3S, R70W. Called mica schist unit in earlier reports. Ranges in thickness from 0 on northwest flank of the Baughman nose to 5,000 ft along mountain front. Variation in thickness thought to be due to unconformable relation with overlying Cressman's Gulch Formation (new). Overlies Belcher Hill Formation (new). Geologic map. Cross section. Consists of facies A, B and C (east to west). Facies A is thinly laminated, micro-crenulated, fine-textured, medium-gray micaceous schist, and has a few quartz lenses and stringers. Facies B is highly micaceous, medium-textured schist and gneissic schist. Facies C is highly muscovitic-sillimanitic schist and gneissic schist with occasional thin beds of fine-grained quartzite, and numerous quartz and granite pegmatite lenses and pods. Precambrian age.

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

Is one of several units defined in a narrow belt along east-central Front Range, near Golden, Jefferson Co, CO in Southern Rocky Mountain region. Of doubtful use elsewhere. Assumed direction of stratigraphic sequence is debatable. Belongs with pre-1,700 m.y. metamorphic complex, or of Precambrian X age.

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