Age:Mississippian Type designation:Type locality: The name “Bethel Sandstone” was first used by Butts (1917, p. 63-64) in describing exposures of thick-bedded coarse-grained sandstone and slabby sandstone 10 to 40 ft (3 to 12 m) thick in the vicinity of Bethel School, near Marion, Crittenden County, Kentucky (Gray, 1970, 1986). History of usage:Miscorrelation: When first recognized in Indiana, this unit was identified (Malott, 1919, p. 9) with the Sample Sandstone Member of the Gasper Oolite (Limestone) of Butts (1917, p. 70-73) (Gray, 1970, 1986).
Description:In Indiana the Bethel Formation includes gray, clayey shale, ripple-bedded fine-grained sandstone, thin beds of coal, and in places underclay and nonstratified sandstone that contain abundant rootlet compressions (Gray, 1986). It ranges from 1 to 42 ft (0.3 to 13 m) in thickness (Sullivan, 1972, p. 14), and on the outcrop it generally forms covered slopes (Gray, 1986).
Boundaries:Over most of this area the Bethel Formation conformably overlies the Paoli Limestone (Gray and others, 1960). The Bethel Formation is overlain conformably by the Beaver Bend Limestone or disconformably by the Mansfield Formation (Morrowan) (Gray, 1970). Where the West Baden clastic belt reaches the outcrop in Greene and Owen Counties, several sections described by Malott (1952, p. 45-49) show clastic rocks of the West Baden Group resting disconformably on the Ste. Genevieve Limestone (Gray, 1986). In different areas, therefore, the same horizon, the base of the Bethel Formation and the base of the West Baden Group, is conformable where the Bethel can be recognized as a discrete formation and disconformable where it cannot (Gray, 1986). Correlations:Rocks that were formerly referred to the middle part of the Paint Creek Formation in the Illinois standard section are now assigned to the Bethel Formation, and use of the name “Paint Creek” (with group rank) is restricted to western Illinois (Atherton and others, 1975, p. 153-154; Gray, 1986). The name “Mooretown” remains in use for equivalent strata in Kentucky (Gray, 1986). Economic Importance:Industrial Minerals: Cement products from the Bethel Formation (Mississippian) include the following: Portland and masonry cement from a quarry in Putnam County (Shaffer, 2016).
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Regional Indiana usage:
Illinois Basin (COSUNA 11)
Misc/Abandoned Names:Mooretown Sandstone, Ohio River Formation, Sample Sandstone Member Geologic Map Unit Designation:Mbl 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 terminologyNames 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: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. 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. 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. 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. 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., and Atherton, Elwood, 1948, Subsurface correlations of lower Chester strata of the Eastern Interior Basin: Journal of Geology, v. 56, p. 269–287. |
For additional information, contact:
Nancy Hasenmueller (hasenmue@indiana.edu)Date last revised: August 16, 2021