Usage:
Big Horse Limestone Member of Orr Formation (UT*)
Big Horse Limestone (recognized locally along State line of NV*,UT*)
Geologic age:
Middle Cambrian (Lincolnian; Marjuman)*
Type section, locality, area and/or origin of name:
Type section (=type section of Orr Formation): composite of two measured sections on northeast side of Orr Ridge, House Range, Millard Co., UT. Lower part on northeast face of hill 6593, northeast side of Orr Ridge, from about 6,200 to 6,500+ ft elevation, in SE/4 sec. 28 [unsurveyed], T. 18 S., R. 13 W., [approx. Lat. 39 deg. 12 min. 41 sec. N., Long. 113 deg. 18 min. 30 sec. W.], and remainder about 0.5 mi south, along crest of ridge between Little Horse Canyon and Big Horse Canyon, from about 6,400 to 7,000 ft elevation, in SW/4 SE/4 NE/4 sec. 33 [unsurveyed], T. 18 S., R. 13 W., [approx. Lat. 39 deg. 12 min. 06 sec. N., Long. 113 deg. 18 min. 42 sec. W.], Notch Peak 15-min quadrangle, House Range, Millard Co., west-central UT (Hintze and Palmer, 1976).
Reference section (=reference section of Orr Formation): about 0.5 mi south of Lawson Cove Reservoir on east side of Hill 6190, in SW/4 sec. 29, T. 24 S., R. 14 W., [approx. Lat. 38 deg. 41 min. 24 sec. N., Long. 113 deg. 26 min. 52 sec. W.], northern Wah Wah Mountains, Frisco Peak 15-min quadrangle (1960), Millard Co., west-central UT (Hintze and Palmer, 1976).
Named from exposures in Big Horse Canyon, House Range, Millard Co., west-central UT (Hintze and Palmer, 1976).
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 ([ ]).