Very striking and graphic engraved map that details the geological composition the United States. Nine different geological types are shown in different hand color. Locates Eozoic, Silurian, Devonian and Lower Carboniferous, Coal Measures and Permo-Carboniferous, Triassic and Jurassic, Cretaceous, Tertiary, Alluvium, and Volcanic. Includes political boundaries, major cities and watersheds. The map is based on Hitchcock’s map for the American Institute of Mining and was published by O.W. Gray and Son of Philadelphia.

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Condition: A

A colorful example with only minor imperfections in the blank margins including a short edge tear at bottom that just passes the border and has been closed on verso with hinge tape. The centerfold has been reinforced with hinge tape on verso.