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National Geologic Map Database

Geologic Unit: Horseshoe

Usage:

Horseshoe Formation (ID)


Subunits:

(alphabetical) --all in ID: Blacksmith coal bed (informal), Boise coal bed (informal).


Geologic age:

Late Cretaceous


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

Composite section (surface and subsurface): four sections in the Horseshoe Creek area, including a measured surface section on the ridge north of Horseshoe Creek, and 2 subsurface sections from the Philips Horseshoe No. 1 well and the Sunmark-Supron Miner Estate 4-34 well, Big Hole Mountains, T. 5 N., R. 44 E., Garns Mountain 7.5-min quadrangle, Teton Co., ID (Entzminger, 1979).


AAPG geologic province:

Idaho Mountains 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 ([ ]).