(HHG & SJK)
Buffalo Wallow Group,
Type locality and use of name in Indiana: The Kinkaid Limestone was named by Stuart Weller (1920b, p. 218) for exposures of gray and yellow-gray cherry limestone, varicolored shale, and a few thin beds of sandstone along Kinkaid Creek, Jackson County, Ill. Total thickness of this unit is as much as 140 feet (43 m) (Weller, 1920a, p. 406-407). As redescribed by Swann (1963, p. 42-44, 72) and Willman and others (1975, p. 162), it consists of upper and lower limestone members and a middle shale and limestone member that have an aggregate thickness of 120 to 170 feet (37 to 52 m). The Kinkaid Limestone is a unit in the standard Chesterian section.
In southern Indiana, outcropping limestone equivalent to the lower part of the Kinkaid Limestone of Illinois was originally named the Negli Creek Limestone by Malott (1925). This unit was later correlated with the Kinkaid (Malott, 1931, p. 222), but Swann (1963, p. 42-43) restored the term Negli Creek with member status and applied it to the lowest member of the Kinkaid Limestone. The term Negli Creek has been adopted for outcrop usage as the uppermost member of the Tobinsport Formation (Gray, 1978, p. 12-13). (See also the article on the Negli Creek Limestone Member.)
Description: In Indiana the name Kinkaid Limestone is now restricted to subsurface usage. It is recognized in most of Posey County, adjacent western Gibson County, and in parts of Perry, Spencer, and Warrick Counties. Where the formation is not greatly reduced by pre-Pennsylvanian erosion, it is 130 to 150 feet (40 to 46 m) thick and is divisible informally into three members. The uppermost member (Goreville Limestone Member of Swann, 1963) is 18 to 20 feet (5 to 6 m) thick and consists of gray to gray-tan coarse to fine grainstone to packstone and minor amounts of chert. The middle member (Cave Hill Shale Member of Swann, 1963) is 80 to 100 feet (24 to 30 m) thick and is predominantly dark gray shale, but it also includes minor amounts of red and green shale. The lower member, the Negli Creek Limestone Member, is 18 to 20 feet (5 to 6 m) thick and is tan-gray to brown medium to very fine grainstone to mudstone.
The Kinkaid Limestone overlies the Degonia Sandstone with presumed conformity and is overlain disconformably by the Mansfield Formation (Morrowan) except in a few places in Posey County where the Grove Church Shale (Chesterian Series) intervenes. For Indiana usage the Kinkaid Limestone is here assigned to the Buffalo Wallow Group.
Correlation: The Kinkaid Limestone or some part of it is recognized throughout much of the Illinois Basin. In southern Illinois it is assigned to the zone of the crinoid Pterotocrinus tridecibrachialis Gutschick, the most widely distributed Pterotocrinus species in eastern North America (Horowitz and Strimple, 1974). The Kinkaid apparently correlates with rocks assigned to North American foraminiferal Zone 18 of Mamet and Skipp (1971) and to the Namurian Series (Zone E2) of European usage. On the basis of its conodont fauna, the outcropping Kinkaid of southern Illinois has been assigned to the Kladognathus-Cavusgnathus naviculus Assemblage Zone in the standard North American donation (Collinson, Rexroad, and Thompson, 1971).