Manganese deposits in the Nevada district, White Pine County, Nevada

The Nevada district, 10 miles southeast of Ely, Nevada, has been one of the principal producers of manganese ore in the State.Between 1917 and 1938 more than 15,000 tons of ore containing .between 26 and 47 percent of manganese was shipped from the district; in addition about 5,000 tons of gold-silver ore has been shipped.The rocks in the district are interbedded limestones and shales of Mississipplan age.For the most part they dip steeply to the southwest, but they are locally folded and have been cut by three sets of faults thrust faults, tear faults, and normal faults.The manganese ore bodies are irregular, podllke, or tabular in shape.Most of them extend along normal faults, but others replace limestone adjacent to faults, and one is along a thrust fault.They are almost completely oxidized to a depth of 170 feet.The ore consists predominantly of pyrolusite with some wad and psilomelane.These minerals may have been formed by the oxidation of rhodochrosite and alabandite.The ore remaining in stopes and found by diamond drilling indicates reserves estimated at 15,000 tons containing 30 percent or more of manganese.An additional 10,000 tons of 30-percent ore may lie in unexplored ground.It is estimated that about 5,000 tons of ore containing between 10 and 30 percent of manganese remains in the stopes, in pits, and on the dumps.