Named as a member of Cressman's Gulch Formation for exposures on ridge north of Chase Ranch, Ralston Buttes quad, Jefferson Co, CO in Southern Rocky Mountain region. Type area designated in NE1/4 sec 20, T2S, R70W. Consists of fine-grained, massive to thin-bedded [quartzite]. Occurs at several stratigraphic positions in formation. Is 10 to 20 ft thick. Overlies and underlies unnamed parts of Cressman's Gulch. Not shown on geologic maps or cross section. Precambrian age.
Source: GNU records (USGS DDS-6; Denver GNULEX).
As a member of Cressman's Gulch Formation 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).
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