Usage:
Speck Mountain Formation of Thrifty Group (TX)
Speck Mountain Limestone Member of Thrifty Formation of Cisco Group (TX*)
Geologic age:
Late Pennsylvanian (Virgilian)*
Type section, locality, area and/or origin of name:
Named from Speck Mountain, Coleman Co., Colorado River region, central TX. Well exposed at top of mountain (Drake, 1893; US geologic names lexicons, USGS Bull. 896, 1200).
AAPG geologic province:
Bend arch*
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 ([ ]).