Red Butte Mining District, Box Elder County, Utah, USAi

Regional Level Types
Red Butte Mining District	Mining District
Box Elder County	County
Utah	State
USA	Country

The Red Butte mining area is located in the central Grouse Creek Mountains of northwestern Box Elder County. Red Butte is a newly designated district which was previously included in the Rosebud district to the south. The district is separated here in an effort to make the district boundaries more accurately reflect the individual intrusive-centered, paleohydrothermal systems. In the case of Red Butte, the mineralization is probably related to the nearby southern Red Butte stock (0.8 mi) rather than the distant (6.6 mi) Immigrant Pass plutonic complex of the Rosebud district.
The Grouse Creek Mountains are part of the Albion–Raft River–Grouse Creek metamorphic core complex in the Basin and Range Province. The Grouse Creek Mountains are geologically complex, and the Red Butte district includes Precambrian rocks in the footwall of a major low-angle normal fault that has an attenuated sequence of upper Paleozoic sedimentary strata in the hanging wall. Doelling (1980) indicates that the Grouse Creek range has been rotated westward by Neogene Basin and Range extension.
In the Red Butte district, the core of the range is Neoarchean Green Canyon Complex granite gneiss and some thin Neoproterozoic metasedimentary rocks intruded by a pair of small (1 to 2 sq mi), Oligocene (~25 Ma) quartz monzonite stocks (Miller and others, 2012). The stocks are light gray, medium grained, equigranular, biotite quartz monzonite. The stocks are cut by small, leucocratic alaskite and aplite dikes (Todd, 1973) and have modest associated magnetic highs. A west-dipping detachment fault on the crest of the range separates the footwall Precambrian metamorphic rocks and Oligocene quartz monzonite from weakly metamorphosed blocks of Mississippian, Pennsylvanian, and Permian sedimentary rocks in the hanging wall. The top of the southern quartz monzonite stock is cut and mylonitized by the detachment fault (Doelling, 1980).
The main Red Butte underground mine workings are in Ingham Canyon and consist of a series of adits driven from the bottom of the canyon to both the north and south. The workings develop a series of narrow, rusty, clayey, Ag-Au quartz fissures in Mississippian Chainman Shale (Doelling, 1980). The mine has no reported production, but some ore may have been shipped.