Geologic Unit: Grand Prize

Usage:

Grand Prize Formation of Sun Valley Group (ID*)

Geologic age:

Middle Pennsylvanian (Desmoinesian) to early Permian (Leonardian)*

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

North slope, Pole Creek Canyon at confluence with Grand Prize Creek, Horton Peak 7.5-min quadrangle, Custer Co., ID (Hall, 1985).
Supplemental reference section (composite): at Fourth of July Creek, Custer Co., ID, within Obsidian and Washington Peak quadrangles. Basal 500 m measured in Strawberry Basin, north of Blackman Peak at 9,800 to 10,111 ft elevation; 500 to 2,500 m interval measured on ridge north of Fourth of July Creek at 7,800 to 9,200 ft elevation (Mahoney and Sengebush, 1988).
Reference section (composite): member 1 in Strawberry basin, Lat. 44 deg. 04 min. 28 sec. N., Long. 114 deg. 39 min. 32 sec. N., 9,800 to 10,111 ft elevation, north of Blackman Peak, Blaine Co., ID; members 2, 3, 4 are north of Fourth of July Creek, Lat. 44 deg. 03 min. 18 sec. N., Long. 114 deg. 43 min. 48 sec. W. Other reference section for members 2, 3, 4 on ridge south of Champion Lakes.

AAPG geologic province:

Idaho Mountains province*
Snake River basin*