Description: ÒProduction of mercury, arsenic, and bauxite (aluminum ore) in the United States in 1918 ÉSize of block is proportional to percentage of total production of the United States; percentage indicated also by figures. A cross represents less than 1/2 per cent. — Department of the Interior, 1921
Source: Department of the Interior , World Atlas of Commercial Geology (Washington, DC: Department of the Interior , 1921) Plate 64
Map Credit: Courtesy the private collection of Roy Winkelman |
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