Fossils in Our Lives Indiana place names reveal its prehistoric heritage. Indiana communities named for coal include Carbon, Carbondale, Coal Bluff, Coal City, Coal Creek, and Coalmont. Oil probably led to the naming of Petroleum. Gas City and Gaston are named for natural gas. The village of Limedale is named for its limestone quarries and a lime kiln.
Brachiopods are also especially common here.
In some places, beds as much as two feet thick contain so many brachiopods that their shells touch each other. Such a rock is called a brachiopod coquina.