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National Geologic Map Database

Geologic Unit: Thorn Ranch

Usage:

Thorn Ranch Tuff (CO*)


Geologic age:

Tertiary*
Oligocene*


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

Along mesa near Thorn Ranch, in S/2 sec. 23 and N/2 sec. 26, T. 17 S., R. 73 W., Fremont Co., CO (Epis and Chapin, 1974).


AAPG geologic province:

Denver 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 ([ ]).