- Usage in publication:
-
- Chase Ranch Quartzite Member
- Modifications:
-
- Named
- Dominant lithology:
-
- Quartzite
- AAPG geologic province:
-
- Southern Rocky Mountain region
Summary:
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).
- Usage in publication:
-
- Chase Ranch Quartzite Member
- Modifications:
-
- Overview
- AAPG geologic province:
-
- Southern Rocky Mountain region
Summary:
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).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).