Pennsylvanian System

Type area and use of name in Indiana: The name Bond Formation was first used for rocks exposed in Bond County, southwestern Illinois (Kosanke and others, 1960, p. 38). Use of this name was extended to Indiana for rocks between the base of the Shoal Creek Limestone Member (Carthage Limestone Member of present usage) and the top of the Livingston Limestone Member in the McLeansboro Group (Wier and Gray, 1961; Wier, 1961, 1965).

Description: In Indiana the Bond Formation consists in ascending order of the Carthage Limestone, St. Wendel Sandstone, Fairbanks Coal, Riverview Limestone, and Livingston Limestone Members and unnamed beds of shale, sandstone, and coal. The formation is made up of about 95 percent sandstone, shale, and siltstone and minor amounts of limestone, clay, and coal. The entire formation is present only in two widely separated areas in the state, western Sullivan County and the area of northwestern Posey County and southwestern Gibson County. Because of the distance between these two areas, exact correlation and corresponding thicknesses are uncertain, but the Bond Formation is about 150 feet (46 m) thick in Sullivan County and 250 feet (76 m) thick in northwestern Posey County (Wier, 1965, p. 114).