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National Geologic Map Database

Geologic Unit: Orr

Usage:

Orr Formation (UT*)


Subunits:

(alphabetical) --all in UT*: Big Horse Limestone Member, Candland Shale Member, Corset Spring Shale Member, Johns Wash Limestone Member, Sneakover Limestone Member, Steamboat Pass Shale Member.


Geologic age:

Late Cambrian*


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

Type section (composite): two measured sections on northeast side of Orr Ridge, House Range, Millard Co., UT. Lower part on northeast face of hill 6593, in SE/4 sec. 28, T. 18 S., R. 13 W.; remainder in sec. 33, T. 18 S., R. 13 W., Notch Peak 15-min quadrangle (Hintze and Palmer, 1976).
Type locality: Orr Ridge, a spur extending east from main mass of Notch Peak, on south side of Weeks Canyon, House Range, [Millard Co.], western UT (Walcott, 1908).


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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).