Age:

Mississippian

Type designation:

Type locality: The Buffalo Wallow Formation was named by Butts (1917, p. 112-117). The name is from Buffalo Wallow, a cirque-like excavation in the shales of the formation on the highway 2 miles (3.2 km) west of Cloverport, Kentucky (Butts, 1917, p. 112).

History of usage:

Extended: About 60 years ago the name "Buffalo Wallow Formation" was also applied in Indiana (Malott and Thompson, 1920; Cumings, 1922, p. 518; Gray, 1986). The term was not, however, adopted by Malott (1925) in his study of upper Chesterian rocks (Gray, 1986).

Revised rank and expansion: At group rank and in a somewhat expanded sense, the name was adopted by Gray (1978) to include all outcropping Mississippian rocks above the Glen Dean Limestone (Gray, 1986). This usage differs from that in Kentucky in rank assignment and by including the Tar Springs Formation in the group, but it "expresses well the lithologic unity of the upper Chesterian and it retains an old and established name" (Gray, 1978, p. 5; Gray, 1986).

Overview: As originally defined for Indiana usage, the term "Buffalo Wallow Group" was not extended into the subsurface (Gray, 1978), but it is now finding application there in a substantially identical sense–that is, to include all Mississippian rocks above the Glen Dean Limestone (Gray, 1986). In surface usage the three formations of the group, in ascending order, are the Tar Springs, Branchville, and Tobinsport Formations (Gray, 1986). In the subsurface the component formations are the Tar Springs Formation, the Vienna Limestone, the Waltersburg Formation, the Menard Limestone, the Palestine Formation, the Clore Formation, the Degonia Formation, the Kinkaid Limestone, and the Grove Church Shale (Droste and Keller, 1995).

Description:

The Buffalo Wallow Group is dominantly shale, mudstone, and siltstone, but it also contains prominent beds of sandstone and limestone, some of which are laterally extensive (Gray, 1986). The group exhibits its maximum surface thickness of about 270 ft (82 m) near Tobinsport on the Ohio River; in the subsurface its maximum thickness is about 675 ft (206 m) in Posey County (Droste and Keller, 1995).

Distribution: The group thins progressively and is truncated northward as a result of pre-Pennsylvanian erosion (Gray, 1986). Along the outcrop it reaches no farther north than southwestern Orange County (Gray, 1986).

Correlations:

Rocks now assigned to the Buffalo Wallow Group were found by Collinson, Rexroad, and Thompson (1971) to span three conodont zones of North American standard usage: in descending order they are the Kladognathus-Cavusgnathus naviculus Assemblage Zone, the Kladognathus primus Assemblage Zone, and the upper part of the Gnathodus bilineatus-Kladognathus mehli Assemblage Zone (Gray, 1986). The group equates with rocks within North American foraminiferal Zones 17 and 18 of Mamet and Skipp (1971) and with part of the Namurian Series (Zones E1 and E2) of European usage (Gray, 1986).

Regional Indiana usage:

Illinois Basin (COSUNA 11)
Supergroup: none
Group: Buffalo Wallow Group
Illinois Basin Margin (COSUNA 12)
Supergroup: none
Group: Buffalo Wallow Group

Misc/Abandoned Names:

None

Geologic Map Unit Designation:

Mbw

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:

Butts, Charles, 1917, Mississippian formations of western Kentucky: Descriptions and correlations of the Mississippian formations of western Kentucky: Kentucky Geological Survey, ser. 4, v. 5, pt. 1, 119 p.

Collinson, Charles, Rexroad, C. B., and Thompson, T. L., 1971, Conodont zonation of the North American Mississippian: Geological Society of America Memoirs 127, p. 353–394.

Cumings, E. R., 1922, Nomenclature and description of the geological formations of Indiana, in Logan, W. N., Cumings, E. R., Malott, C. A., Visher, S. S., Tucker, W. M., Reeves, J. R., and Legge, H. W., Handbook of Indiana geology: Indiana Department of Conservation Publication No. 21, pt. 4, p. 403–570.

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.

Gray, H. H., 1978, Buffalo Wallow Group upper Chesterian (Mississippian) of southern Indiana: Indiana Geological Survey Occasional Paper 25, 28 p.

Gray, H. H., 1986, Buffalo Wallow Group, in Shaver, R. H., Ault, C. H., Burger, A. M., Carr, D. D., Droste, J. B., Eggert, D. L., Gray, H. H., Harper, Denver, Hasenmueller, N. R., Hasenmueller, W. A., Horowitz, A. S., Hutchison, H. C., Keith, B. D., Keller, S. J., Patton, J. B., Rexroad, C. B., and Wier, C. E., Compendium of Paleozoic rock-unit stratigraphy in Indiana–a revision: Indiana Geological Survey Bulletin 59, p. 24–25.

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.

Malott, C. A., 1925, The upper Chester of Indiana: Indiana Academy of Science Proceedings, v. 34, p. 103–132.

Malott, C. A., and Thompson, J. D., Jr., 1920, The stratigraphy of the Chester Series of southern Indiana [abs.]: Science, new ser., v. 51, p. 521–522.

Mamet, B. L., and Skipp, B. A., 1971, Lower Carboniferous calcareous Foraminifera–preliminary zonation and stratigraphic implications for the Mississippian of North America: Sixieme Congres International de Stratigraphie et de Geologie du Carbonifere Sheffield, 1967, Compte rendu, v. 3, p. 1,129–1,146.

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.