Usage:
Huerfanito Bentonite Bed of Lewis Shale (CO*,NM*)
Geologic age:
Late Cretaceous*
Type section, locality, area and/or origin of name:
Type section (subsurface): depth-interval 2,550 to 2,562 ft, El Paso Gas Huerfanito Unit 60 well, in SW/4 SW/4 sec. 4, T. 26 N., R. 9 W., San Juan Co., NM (Fassett and Hinds, 1971).
AAPG geologic province:
San Juan 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 ([ ]).