Indiana limestoneIndiana limestone
is a common term for Salem limestone, a geological formation primarily found in southern Indiana
. Salem limestone, like all limestone
, is a rock primarily formed of calcium carbonate
. The limestone was deposited over millions of years as marine fossils decomposed at the bottom of a shallow inland sea which covered most of the present-day Midwestern United States
The first Indiana limestone quarry was started in 1827, and by 1929 Hoosier quarries yielded 12 million cubic feet of usable stone. Buildings such as the Empire State Building, The Pentagon, and the U.S. Holocaust Museum feature Indiana limestone in their exteriors.