Buena Vista Mine, Nevada
The Buena Vista Mine is located 21 miles (34 km) south of Lovelock, Nevada. In the past, the area has been known as the Mineral Basin (discovered in 1880), though another name for the area has been the Buena Vista District. There are at least two other Buena Vista Mining Districts in Nevada, one is located near Unionville, Nevada, the other located in Esmeralda and Mineral counties near the California border. The nearby Buena Vista Hills are named for the mine. The district encompasses roughly 21 square miles (54 km2) of mineral and surface rights, and is one of the largest un-mined iron ore resources in the western United States.
In the late 1880s, 500 tons of ore were shipped to Union Iron Works in San Francisco. However, when it was determined that most of the ore was on Central Pacific Railroad land, operations were suspended. Production was recorded in 1943 and continued intermittently on the Thomas, Dodge, Segerstrom, and Buena Vista deposits until the 1960s. Total production was about 4 million tons, all of it high-grade 'lump' ore consisting of magnetite and minor hematite.
In 2006 high steel prices renewed iron ore exploration which renewed interest in the district. Several different companies funded exploration efforts, including geophysical exploration as well as drilling. This exploration significantly boosted reserves.
In late 2009 for the first time, the entirety of the Buena Vista Iron District was presented for sale by Western Resources Group and priced at $75 million.
In June, 2011, Richmond Mining LTD, an Australian mining company (RHM:ASX), received a special use permit to develop the Buena Vista Iron Ore Mine in Churchill County, Nevada. The permit includes a 25 miles (40 km) slurry pipeline north to Colado Siding near Interstate 80 and annual use of up to 1,750 acre feet (570,000,000 US gal) of water.
In 2011 an exploration campaign was undertaken by Nevada Metal Mines LLC in areas of the district that had previously been overlooked. The exploration, which included ground magnetic surveys and geophysical data analysis of those surveys, has indicated the potential for several million tons of iron ore. Samples taken from these areas all assayed to be of direct shipping grade, in excess of 66% total iron.
The district is located within a Middle Jurassic volcano-plutonic complex composed of basaltic lavas and volcaniclastics underlain and intruded by gabbroic rocks. Mafic dikes are abundant and form sheeted dike swarms. Deposition of iron was not associated with silicification or sulfidation. Host rocks contain veins and large accumulations of pure magnetite in structural or breccia zones, or are impregnated with clots of magnetite in all size ranges. Magnetite is readily liberated from the host material by crushing and the iron removed by magnetic or gravity separation. Veins of pure magnetite in excess of 10 feet thick are common in the open pits and drill intercepts. Oxidation has produced some hematite.
Iron ore reserves
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- Johnson and Barton (2000b)