Report issued by the Bureau of Mines regarding studies conducted on zinc-lead mines in Clark County, Nevada. Physical qualities of the mine, equipment used, and methods of sampling are presented. This report includes tables, and maps.

Report issued by the U.S. Bureau of Mines regarding specific manganese ore from Nevada and its use in electrolytic production. The development processes and methods are presented. This report includes tables, maps, illustrations, and photographs.

Abstract: The Three Kids manganese district, in Clark County, Nev., has produced between 15,000 and 20,000 tons of ore, which contained between 30 and 40 percent manganese, 1.5 percent iron, and 12 percent silica. It is estimated that the reserves in the district aggregate about 5,500,000 tons of ore averaging about 10 percent manganese. Of this amount about 800,000 tons contains more than 20 percent manganese and 4,700,000 tons contains from 5 to 20 percent manganese. The manganese ore is a sedimentary deposit and consists of wad interbedded with lake or playa sediments belonging to the Muddy Creek formation of Pliocene (?) age. Where the manganese content is as high as 30 percent, the wad forms thick massive beds separated by thin almost barren partings. Where the content is low, the wad forms very thin lenses or small irregular blebs scattered through sandstone, or a cement for the sand grains. The zone of manganiferous beds ranges from about 10 to 75 feet in aggregate thickness, but at most places the thickness is between 25 and 40 feet.

From Introduction: "This report records a chapter in the history of the development of an electrolytic manganese industry in the United States."