U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database

Geologic Unit: Knowles

Usage:

Knowles Limestone of Cotton Valley Group (AR?,LA,TX?)


Geologic age:

Jurassic, Late


Type section, locality, area and/or origin of name:

Type section (subsurface): depth-interval 8,240 to 8,550 ft, California Company T.C. Colvin No. 1 well, in SE/4 NW/4 sec. 14, T. 19 N., R. 4 W., Lincoln Parish, LA (Mann and Thomas, 1964).


AAPG geologic province:

Arkla 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 ([ ]).