The National Geologic Map Database is migrating to a new infrastructure. We apologize for any service disruptions during this process.
|
|---|
- Usage in publication:
-
- Speck Mountain clay bed
- Modifications:
-
- Original reference
- Dominant lithology:
-
- Clay
- Sandstone
- AAPG geologic province:
-
- Bend arch
Summary:
Pg. 387, 407. Speck Mountain clay bed in Cisco division. Fossiliferous sandy clay, bluish, purplish, or slightly red, 25 feet thick, with a little sandstone and some carbonaceous shaly clay. Member of Cisco division [Cisco is 2nd from top of 5 Carboniferous divisions of Cummins, 1891]. Overlies BELLEROPHON bed and underlies Speck Mountain limestone bed. Age is Pennsylvanian.
[Named from Speck Mountain, Coleman Co., Colorado River region, central TX.] Well exposed at base of mountain.
Source: Publication; US geologic names lexicon (USGS Bull. 896, p. 2038).
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 ([ ]).