Geology and mineral deposits, east flank of the Elkhorn Mountains, Broadwater County, Montana

Abstract

The principal skarn deposits are west of Radersburg and at Diamond Hill; titaniferous magnetite has been mined west of Radersburg. Perhaps as much as half the ore mined from the several types of vein deposits has been oxidized or partly oxidized; only a few veins have been profitably mined below the zone of oxidation. Despite extensive mining and prospecting, the area is considered favorable for discovery of additional mi.peral deposits. For example, auriferous py.rite veins or ancient gold •placers might be concealed beneath the relatively thin Cenozoic deposits south of the Keating and Ohio Keating mines near Radersburg, and the untested outwash gravels along and near Cold Springs Gulch would seem to warrant testing for gold. l L 1SEDIMENTARY ROCKS

Montana Mineral Locality Index

“…33, T. 5 N., R. 1 W.: calcite, cerussite, chlorargyrite, dolomite, fluorite (purple crystals), galena, hemimorphite, pyrite, smithsonite, sphalerite (Klepper et al 1971). Sadie S claim, sec.…”

“…13, T. 5 N., R. 1 W.: cerussite, galena, vanadinite (microcrystals), wulfenite (crystals) (Klepper et al 1971).…”

“…16, T. 5 N., R. 1 W. Located N of Johnny Gulch; Chris Tucker of Billings is mining specimens, replacement deposit in the upper Mission Canyon limestone: aragonite, aurichalcite (microcrystals), barite, calcite, cerussite, chlorargyrite (microcrystals), descloizite (microcrystals), dolomite, fluorite, galena, gold, hemimorphite (crystals to 2 cm), mimetite, plattnerite, pyromorphite, quartz, smithsonite, vanadinite* (gray, red, brown to black crystals), willemite (microcrystals), wulfenite (crystals) (Klepper et al 1971;Tucker 2006a).…”

“…28, T. 5 N., R. 1 W.: aragonite (crystals), cerussite (crystals), descloizite, galena, plattnerite, vanadinite (crystals), wulfenite (microcrystals) (Klepper et al 1971;Tucker 2006a).…”

Mineral resources of the Elkhorn Wilderness Study Area, Montana

“…The geologic map of the study area (pi. 1) was compiled from the reports by ; Klepper, Ruppel, Freeman, and Weeks (1971) ;Becraft, Pinckney, and Rosenblum (1963);and Smedes (1966); and details were added locally based on our mapping. The synopsis of geology presented here is drawn largely from these papers, supplemented by subsequent summaries and topical reports by these authors and their co-workers.…”