- Usage in publication:
-
- Morgan Creek limestone member*
- Modifications:
-
- Named
- Dominant lithology:
-
- Limestone
- AAPG geologic province:
-
- Llano uplift
Summary:
Named as a member (1 of 5) of Wilberns formation for exposures on both north and south forks of Morgan Creek, Burnet Co., TX on the Llano uplift. The type section is on a point just north of the junction of the two forks. Overlies Welge sandstone member (named), basal member of Wilberns. Underlies Point Peak shale member (named) of Wilberns. Is 110 ft thick at type; averages 120 ft thick; ranges between 70 and 160 ft thick. Consists of medium- to coarse-grained, glauconitic, well-bedded limestone. The lower beds are sandy, red that grade upward to green-gray. Locally, upper part is shaly. Individual limestone beds are 4 inches to 1 ft-thick. Known for its ELVINIA fauna in lower part and conaspid fauna in upper part. Some of the limestone is ovlitic; some shale. Cross sections of Late Cambrian 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 ([ ]).