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National Geologic Map Database

Geologic Unit: Arkadelphia

Usage:

Arkadelphia Marl (AR*,LA*,TX*)
Arkadelphia Formation (AR)
Arkadelphia Marl of Navarro Group (LA*,TX)


Geologic age:

Late Cretaceous (Maastrichtian; Gulfian Provincial Epoch)*


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

Typical outcrops (modern sense) in southwestern AR: 5 to 7 mi north and northwest of Hope [Hempstead Co.]; along AR Highway 19, between U.S. Highway 30 and Prescott [Nevada Co]; and in the Oakhaven area [Hempstead Co.] (McFarland, 2004; see also Dane, 1929).
Named from outcrops at Arkadelphia, Clark Co., southwestern AR (Hill, 1888). [These strata no longer considered part of Arkadelphia (see Dane, 1929, McFarland, 2004).]


AAPG geologic province:

Anadarko basin*
Arkla basin*
East Texas basin*
Ouachita folded belt*


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).