Usage:
Ryan Spring Formation of Needles Range Group (NV,UT*)
Subunits:
Greens Canyon Tuff Member (NV*,UT*), Mackleprang Tuff Member (NV*,UT*).
Geologic age:
Tertiary*
Oligocene*
Type section, locality, area and/or origin of name:
Type section: west and north of Ryan Spring, in NE/4 sec. 35 and NW/4 sec. 36, T. 28 S., R. 19 W., Miners Cabin quadrangle, Beaver Co., UT (Best and Grant, 1987).
Principal reference section: in secs. 19, 30, and 31, T. 31 S., R. 17 W., and in secs. 24 and 25, T. 31 S., R. 18 W. (Best and Grant, 1987).
AAPG geologic province:
Great Basin province*
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 ([ ]).