The Buffalo Wallow Group is a

geologic group In geology, a group is a lithostratigraphic unit consisting of a series of related formations that have been classified together to form a group. Formations are the fundamental unit of stratigraphy. Groups may sometimes be combined into superg ...

found in

Indiana Indiana ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Michigan to the northwest, Michigan to the north and northeast, Ohio to the east, the Ohio River and Kentucky to the s ...

and

Kentucky Kentucky (, ), officially the Commonwealth of Kentucky, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Illinois, Indiana, and Ohio to the north, West Virginia to the ...

. It is equivalent to the Upper Pope Group as the two share some formations. However many of the formations in the Upper Pope pinch out and are not present in the Buffalo Wallow. The Buffalo Wallow is defined as the formations between the top of the Glen Dean Limestone up to the disconformity where it meets the Mansfield Limestone.

Description

The Buffalo Wallow Group is made up of approximately 70% Shale including fissile shales, claystones, and siltstones. The remaining lithology is made up of mostly

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

and

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

Stratigraphy

The Buffalo Wallow Group contains mostly shale. It is bound on its top and base by limestone formations. The top is marked by an erosional disconformity

Tobinsport Formation

A formation in Illinois containing 4 members that are linked to other formations in the Upper Pope Group. The Negli Creek Limestone of the Kinkaid formation to the west. Mt. Pleasant Sandstone, Bristow Sandstone, and Siberia Limestone. The Siberia is a thin tongue of the Menard formation.

Branchville Formation

The Branchville Formation is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

in Indiana. It has two limestone members, the Leopold Member and the Vienna Member.

Tar Springs Formation

This sandstone unit is 0-150' thick. The Tar Springs consists of interbedded sandstone and shale, creating closed reservoirs within the sand. For this reason it is the largest oil producing formation in Illinois. Estimated to have accounted for more than 60% of the oil production in the state.

References

{{Chronostratigraphy of Kentucky Carboniferous Illinois Carboniferous Indiana Carboniferous Kentucky Shale groups of the United States Sandstone groups of the United States Limestone groups of the United States Geologic groups of Illinois Geologic groups of Indiana Geologic groups of Kentucky