Pennsylvanian System

Type locality and reference section: The name Ditney Formation was first used by Fuller and Ashley (1902, p. 2) for the rocks between the Somerville Limestone (now the West Franklin Limestone Member of the Shelburn Formation) and the Inglefield Sandstone Member in an exposure that included 20 feet (6 m) of shale, thin sandstone, and thin coal in the Ditney Hills in Warrick County, Ind. (secs. 4, 5, and 6, T. 5 S., R. 9 W.). These rocks were later (Wier, 1961, 1965) assigned to the Patoka Formation, but the name Ditney was retained for the coal that was called the Ditney Coal by Fuller and Ashley (1902, p. 2). Wier's reference section was designated in the NW¼SW¼ sec. 13, T. 6 S., R. 11 W., north side of Evansville, Vanderburgh County.

Description: The Ditney Coal Member, a banded, partly shaly coal, is generally less than a foot (<0.3 m) thick. It is separated from the underlying West Franklin Limestone Member by 1 to 20 feet (0.3 to 6 m) of unnamed gray shale and underclay. The northernmost exposure of the Ditney Coal Member in Indiana is in northwestern Vigo County. The coal is not continuously exposed in Vanderburgh and Gibson Counties, where it either was not deposited or underwent erosional cutout by the overlying Inglefield Sandstone Member.

Correlation: The Ditney Coal Member is equivalent to the Chapel (No. 8) Coal Member in Illinois.