Usage:
Semilla Sandstone Member of Mancos Shale (NM*)
Geologic age:
Late Cretaceous (Turonian)*
Type section, locality, area and/or origin of name:
Type section: from 2,000 to 3,000 ft north of Ojo del Espiritu Santo, and about 1 mi east of NM Highway 44, on Ojo del Espiritu Grant, Sandoval Co., NM. Named from outcrops on west side of valley of Arroyo Semilla, northern San Ysidro 15-min quadrangle, Sandoval Co., NM (Dane and others, 1968).
Reference section designated in Hagan basin, in sec. 5, T. 12 N., R. 7 E., NM (Fleming, 1989).
AAPG geologic province:
San Juan basin*
Estancia 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 ([ ]).