U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database
Geologic Unit: Caddo
Map showing publication footprint
  • Usage in publication:
    • Caddo shale
  • Modifications:
    • Original reference
  • Dominant lithology:
    • Shale
  • AAPG geologic province:
    • Ouachita folded belt
Publication:

Purdue, A.H., 1909, Structure and stratigraphy of the Ouachita Ordovician area, Arkansas [abs.]: Geological Society of America Bulletin, v. 19, p. 556-557.


Summary:

Pg. 557. Caddo shale. Shale overlying Crystal Mountain sandstone and underlying Bigfork chert. [Recognized in southwestern Arkansas. Age is Early and Middle Ordovician.]

Source: US geologic names lexicon (USGS Bull. 896, p. 312).


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 ([ ]).

Accessibility FOIA Privacy Policies and Notices

USA Gov U.S. Department of the Interior | U.S. Geological Survey
Supported by the National Cooperative Geologic Mapping Program
Page Contact Information: Personnel
Page Last Modified: Thu 04 Apr 2024 04:42:13 PM MDT