Age:

Mississippian

Type designation:

Type section: In the quarry of the Southern Illinois Rock and Stone Company on the west side of Illinois Highway 37 at the north edge of Buncombe, 4 miles (6.4 km) south of Goreville, SW¼SW¼SE¼ sec. 10, and NW¼NW¼NE¼ sec. 15, T. 12 S., R. 2 E., Vienna quadrangle, Johnson County, Illinois (Swann, 1963, p. 44).

History of usage:

Named: Goreville Limestone Member of the Kinkaid Limestone (Swann, 1963).

Extended: Droste and Keller (1995, p. 14) adopted the name “Goreville Limestone Member” for the unnamed massive upper limestone interval in the Kinkaid Limestone in Indiana.

Description:

In Indiana, the Goreville Limestone Member is a massive medium- to light-gray and brownish-gray limestone and is sparingly dolomitic and cherty (Droste and Keller, 1995). The limestone is fine grained and includes some fossils. The member is typically 20 to 25 ft (6.1 to 7.6 m) thick (Droste and Keller, 1995).

Distribution: Droste and Keller (1995, fig. 16) mapped the Goreville Limestone Member in Posey County and southernmost Gibson County in the subsurface of southwestern Indiana.

Boundaries:

The upper and lower contacts of the Goreville Limestone Member are conformable except in areas where the unit is truncated by the Mississippian-Pennsylvanian unconformity (Droste and Keller, 1995).

Regional Indiana usage:

Illinois Basin (COSUNA 11)
Supergroup: none
Group: Buffalo Wallow Group
Formation: Kinkaid Limestone
Member: Goreville Limestone Member

Misc/Abandoned Names:

None

Geologic Map Unit Designation:

Mkg

Note: Hansen (1991, p. 52) in Suggestions to authors of the reports of the United States Geological Survey noted that letter symbols for map units are considered to be unique to each geologic map and that adjacent maps do not necessarily need to use the same symbols for the same map unit. Therefore, map unit abbreviations in the Indiana Geologic Names Information System should be regarded simply as recommendations.

COSUNA areas and regional terminology

Names for geologic units vary across Indiana. The Midwestern Basin and Arches Region COSUNA chart (Shaver, 1984) was developed to strategically document such variations in terminology. The geologic map (below left) is derived from this chart and provides an index to the five defined COSUNA regions in Indiana. The regions are generally based on regional bedrock outcrop patterns and major structural features in Indiana. (Click the maps below to view more detailed maps of COSUNA regions and major structural features in Indiana.)

COSUNA areas and numbers that approximate regional bedrock outcrop patterns and major structural features in Indiana.

Major tectonic features that affect bedrock geology in Indiana.

References:

Droste, J. B., and Keller, S. J., 1995, Subsurface stratigraphy and distribution of oil fields of the Buffalo Wallow Group (Mississippian) in Indiana: Indiana Geological Survey Bulletin 63, 24 p.

Hansen, W. R., 1991, Suggestions to authors of the reports of the United States Geological Survey (7^th ed.): Washington, D.C., U.S. Geological Survey, 289 p.

Shaver, R. H., coordinator, 1984, Midwestern basin and arches region–correlation of stratigraphic units in North America (COSUNA): American Association of Petroleum Geologists Correlation Chart Series.

Swann, D. H., 1963, Classification of Genevievian and Chesterian (Late Mississippian) rocks of Illinois: Illinois State Geological Survey Report of Investigations 216, 91 p.