Type locality: The Beaver Bend Limestone was named for exposures near Huron, Lawrence County, Indiana, where Beaver Creek makes a conspicuous bend (Malott, 1919, p. 9-10; 1952, p. 103-105; Gray, 1970; Gray and Horowitz, 1986).
The Beaver Bend Limestone is a gray skeletal to oolitic to biomicritic limestone; the unit is generally 10 to 14 ft (3 to 4 m) thick (Malott, 1952, p. 13) but is as thin as 1 ft (0.3 m) (Malott, 1952, p. 27) and as thick as 30 feet (9 m) (Sullivan, 1972, p. 17). Anomalously thick sections commonly are along the edge of linear areas in which the Beaver Bend and Reelsville Limestones are missing and in which much of the West Baden Group is made up of sandstone (Gray and Horowitz, 1986). Sullivan (1972) referred to these linear areas, which trend downdip toward the axis of the Illinois Basin, as the West Baden clastic belt and noted reeflike buildups of limestone along their margins (Gray and Horowitz, 1986).
The Beaver Bend Limestone conformably overlies the Bethel Formation and is overlain conformably by the Sample Formation or disconformably by the Mansfield Formation (Morrowan) (Gray, 1970; Gray and Horowitz, 1986).
The Beaver Bend Limestone is thought to be equivalent to the lower part of the Ridenhower Formation of the Illinois standard section and is recognized as the basal member of that formation (Swann, 1963, p. 35; Atherton and others, 1975, p. 154; Gray and Horowitz, 1986). In the subsurface of the lower Wabash Valley area, the Beaver Bend has commonly been called the Lower Paint Creek Limestone, but this assignment is incorrect, and Sullivan (1972, p. 10) has recommended that the latter term be suppressed in favor of the more precise name “Beaver Bend” (Gray, 1970; Gray and Horowitz, 1986).
Regional Indiana usage:
Illinois Basin (COSUNA 11)
Lower Paint Creek Limestone
Geologic Map Unit Designation:
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.)
Atherton, Elwood, Collinson, Charles, and Lineback, J. A., 1975, Mississippian System, in Willman, H. B., Atherton, Elwood, Buschbach, T. C., Collinson, Charles, Frye, J. C., Hopkins, M. E., Lineback, J. A., and Simon, J. A., Handbook of Illinois stratigraphy: Illinois State Geological Survey Bulletin 95, p. 123-163.
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.
Galloway, J. J., and Kaska, H. V., 1957, Genus Pentremites and its species: Geological Society of America Memoirs 69, ix + 104 p.
Gray, H. H., 1970, Beaver Bend Limestone, in Shaver, R. H., Burger, A. M., Gates, G. R., Gray, H. H., Hutchison, H. C., Keller, S. J., Patton, J. B., Rexroad, C. B., Smith, N. M., Wayne, W. J., and Wier, C. E., Compendium of rock-unit stratigraphy in Indiana: Indiana Geological Survey Bulletin 43, p. 9.
Gray, H. H., and Horowitz, A. S., 1986, Beaver Bend Limestone, 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. 10-11.
Hansen, W. R., 1991, Suggestions to authors of the reports of the United States Geological Survey (7th ed.): Washington, D.C., U.S. Geological Survey, 289 p.
Malott, C. A., 1919, The "American Bottoms" region of eastern Greene County, Indiana–a type unit in southern Indiana physiography: Indiana University Studies, v. 6, no. 40, 61 p.
Malott, C. A., 1952, Stratigraphy of the Ste. Genevieve and Chester formations of southern Indiana: Ann Arbor, Michigan, Edwards Letter Shop, 105 p.
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.
Pohl, E. R., 1970, Upper Mississippian deposits of south-central Kentucky–a project report: Kentucky Academy of Science Transactions, v. 31, nos. 1 and 2, p. 1-15.
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.
For additional information contact:
Nancy Hasenmueller (firstname.lastname@example.org)Date last revised: January 28, 2016