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National Geologic Map Database

Geologic Unit: Conejos

Usage:

Conejos Formation (CO*,NM*)


Subunits:

(alphabetical) --all in CO: La Sauses Member, Manassa Member, Wildhorse Member.


Geologic age:

early Tertiary (early Oligocene; Rupelian)*


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

Named from exposures along Conejos River, Conejos Co., southwestern CO. Most widely distributed and best exposed in Summitville, Conejos, and Del Norte quadrangles, southwestern CO. In general way, outcrops confined to an area about 130 mi long in north and south dimension; about 60 mi wide in northern third, and about 50 mi wide just north of CO-NM State line (Emmons and Larsen, 1923; Larsen, 1935).


AAPG geologic province:

Piceance basin*
San Juan basin*
San Juan Mountains province*
San Luis 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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).