Pennsylvanian System

Type locality and use of name: The Mecca Shale Member is a shortened name given by Wier (1965) to the Mecca Quarry Shale Member named by Zangerl and Richardson (1963, p. 26) for the gray and black carbonaceous shale above the Colchester Coal Member and beneath the Velpen Limestone Member in Parke County, Ind. Zangerl and Richardson's type section is exposed in the sides of gullies in the SW¼NE¼ sec. 29, T. 15 N., R. 8 W., about one-half mile (0.8 km) southeast of Mecca, Parke County, Ind. The top of the Mecca Shale Member is defined by Zangerl and Richardson as the top of sheety gray and black shale, which grades into overlying friable clay shale that is gray to blue to buff.

Description: The Mecca is gray-mottled to black, evenly bedded sheety shale 1 to 7 feet (0.3 to 2.1 m) thick overlying the Colchester Coal Member. The blackest beds can be cleaved into sheets of several square feet without breakage. The Mecca contains large flattened calcareous concretions as much as 3 feet (0.9 m) in diameter in outcrops in Clay and Vigo Counties. Abundant brachiopods, cephalopods, and gastropods have been found in the Mecca shale but are not found everywhere. The pelecypod genus Dunbarella can be found in most outcrops. Fish remains are common at some localities.

Correlation: The Mecca Shale Member is recognized in Illinois as the Mecca Quarry Shale Member and is also probably present in northwestern Kentucky where the underlying Colchester coal has been identified in the subsurface (Jacobson and others, 1985).