Usage:
No current usage.
(†Ralston Formation (CO) replaced with Ralston Creek Formation. See Ralston Creek.)
Geologic age:
Late Jurassic*
Type section, locality, area and/or origin of name:
Type section of shale-marlstone facies: along irrigation ditch and water level on west side of Ralston Reservoir, Ralston Creek, 5 miles north of Golden, in sec. 5, T. 3 S., R. 70 W., Blackhawk quadrangle, Jefferson Co., north-central CO. Facies prevalent between Bear Creek and Ralston Creek (LeRoy, 1946).
Type section of gypsiferous facies: on east side of Glennon Canyon, 1.5 mi southeast of Morrison, in NW/4 sec. 12, T. 5 S., R. 70 W., Morrison quadrangle, Jefferson Co., north-central CO. Facies well exposed along west slope of Dakota hogback between Bear Creek and Turkey Creek (LeRoy, 1946).
AAPG geologic province:
Denver basin
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 ([ ]).