Structure: Northwest-striking structural zones are manifested by granodiorite porphyry dikes and larger elongated intrusive bodies, aeromagnetic lineaments, and regional alignment of mineralized areas. They generally are subtle features that trend N 30? to 40? W and that become evident only after regional mapping and compilation and are not as obvious as the north-striking fault zones. Three such northwest-striking zones have been delineated in the Battle Mountain mining district. The Northwest-striking structural zones in the Battle Mountain mining district are apparently pre-Late Cretaceous in age based on the orientation and age of the monzogranite of Trenton Canyon. The northwest zones may coincide with shattered hingelines of large-scale folds associated with a regional Jurassic compressional event (Doebrich and Theodore, 1996).

Alteration: Alteration consists of varying degrees of contact metamorphism and metasomatism associated with the emplacement and hydrothermal alteration of the Buffalo Valley quartz monzonite porphyry stock. Carbonate sedimentary roacks were altered to cacl-silicate hornfels, quartzite, skarn, wollastonite. More pelitic units were altered to biotite hornfels, siliceous hornfels and quartzite. Hydrothermal alteration of the quartz monzonite stock is strong K-feldspar-botite alteration, sericitic, propylitic, and silicification.

Commodity: Ore Materials: molybdenite, chalcopyrite, sphalerite, galena Gangue Materials: pyrite, pyrrhotite, quartz, diopside, wollastonite, garnet, calcite, tremolite-actinolite, quartz, chlorite, epidote, sericite, K-feldspar, biotite

Deposit: Molybdenite and chalcopyrite mineralization is associated with a celtral zone of stockwork quartz veining, K-spar and sericite alteration in the granodiorite stock and intense silication in the surrounding country rock. Mineralization extends from within the quartz monzonite porphry stock outward into the altered, metamorphosed sedimentary country rocks, and is largely vein-controlled with some disseminated sulfides as well. the Buffalo Valley prospect is a subeconomic Cretaceous quartz monzonite porphyry molybdenum system. Airborne magnetics over the areas of the prospects display broad positive responses that probably correspond to the subsurface extent of igneous rock, altered wallrock, or both (Doebrich and Theodore, 1996).

Deposit type: Porphyry Mo, low-F

Development: There is no recorded production from the prospect, although it has been explored by several major companies throughout its history. Rio Tinto examined it in 1963-1965 and drilled nine holes totalling 3153 feet . Parnasse Company explored it in 1970-1971 and drilled four more holes totalling 6050 feet. Phelps Dodge explored it in 1974-1975 and drilled 6 holes totalling 4148 feet, and Noranda explored the property in 1980-1981 drilling 2 more holes totalling 1940 feet.

Geology: Mesozoic structural and magmatic events in the Battle Mountain mining district included formation of a northwest-striking structural fabric, including faults and broad open folds, and emplacement of Late Cretaceous granodioritic to monzogranitic stocks at Trenton Canyon, Buckingham, and probably at the Buffalo Valley molybdenum prospect just to the west of the southwest corner of the mining district. Low-fluorine porphyry molybdenum systems developed with the Late Cretaceous stocks in the mining district (Doebrich and Theodore, 1996). Mesozoic magmatism in the Battle Mountain mining district consisted of emplacement of two or possibly three Late Cretaceous granodioritic to monzogranitic intrusive complexes that generated low-fluorine porphyry molybdenum mineralizing systems of varying intensity. These include the Buckingham system in the Copper Basin area, the monzogranite of Trenton Canyon, and a weak mineral system at the Buffalo Valley molybdenum prospect (Doebrich and Theodore, 1996). Tectonics and magmatism during the Cenozoic in the Battle Mountain mining district changed from one of largely compression to one of extension. Plutons became generally more intermediate in composition and were emplaced at higher levels, giving rise to a number of porphyry copper and molybdenum-copper systems with associated deposits of base and precious metals. Cenozoic structural and magmatic events in the Battle Mountain mining district included development of north-striking normal fault zones, emplacement of late Eocene to early Oligocene granodioritic stocks and dikes throughout the region, and eruption of volcanic and volcaniclastic rock, ranging in age from early Oligocene to Pliocene. Periodic change in extension directions during the Cenozoic resulted in several generations of normal fault sets with variable orientations (Doebrich and Theodore, 1996).

Ore(s): Mineralization extends from within the quartz monzonite porphry stock outward into the altered, metamorphosed sedimentary country rocks, and is largely vein-controlled with some disseminated sulfides as well.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.

Mineral List

14 valid minerals.

Rock Types Recorded

Note: data is currently VERY limited. Please bear with us while we work towards adding this information!

Select Rock List Type

Alphabetical List Tree Diagram