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National Geologic Map Database

Geologic Unit: Ash Hollow

Usage:

Ash Hollow Formation of Ogallala Group (NE,SD)


Subunits:

(alphabetical): Cap Rock Member (NE,SD), Feldt Ranch Beds (NE), Merrit Dam Member (NE).


Geologic age:

late Tertiary (Miocene; Clarendonian to possibly late? Hemphillian NALMA)


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

Type section: exposures in Ash Hollow Canyon, [in Ash Hollow State Historical Park], southeast of Lewellen, Garden Co., western NE (Engelmann, 1876; Lugn, 1938, 1939).


AAPG geologic province:

Chadron arch
Denver basin
Powder River basin
Salina basin
Sioux uplift


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 ([ ]).