Type section: Near the site of the former town of Alum Cave, Sullivan County, Indiana, in the NW¼NE¼ sec. 25, T. 9 N., R. 8 W. (See Burger and Wier, 1970.)
History of usage:
Named: The name “Alum Cave” was first used by Logan (1930, p. 168) in a columnar section for an indefinite interval of rock above the Springfield Coal Member in Sullivan County, Indiana (Burger and Wier, 1986).
The Alum Cave Limestone Member is typically a medium- to blue-gray limestone that is fine grained, argillaceous, locally sandy, and fossiliferous (Burger and Wier, 1986). In most places the limestone is separated into two beds by a few inches of shale. The thickness of the limestone ranges from 0.1 to 11.8 ft (0.03 to 3.6 m); the average thickness is 2.8 ft (0.8 m) (Burger and Wier, 1970). It generally contains a fauna rich in crinoid columnals, brachiopods, gastropods, and pelecypods. Fusulinids and ostracods are present in places; trilobites are rare (Burger and Wier, 1986).
Burger and Wier (1986) suggested that the Alum Cave Limestone Member was correlative with the St. David Limestone Member of the Carbondale Formation in Illinois. Burger and Wier (1970) noted that the calcareous fossiliferous shale extended into Kentucky.
Regional Indiana usage:
Illinois Basin (COSUNA 11)
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.)
Brown, L. M., Rexroad, C. B., and Zimmerman, A. N., 2016, Conodont paleontology of the Alum Cave Limestone Member of the Dugger Formation (Pennsylvanian, Desmoinesian) in the eastern part of the Illinois Basin: Indiana Geological Survey Occasional Paper 72, 25 p.
Burger, A. M., and Wier, C. E., 1970, Alum Cave Limestone Member, 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. 4-5.
Burger, A. M., and Wier, C. E., 1986, Alum Cave Limestone Member, 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. 4.
Culbertson, J. A., 1932, The paleontology and stratigraphy of the Pennsylvanian strata between Caseyville, Kentucky, and Vincennes, Indiana: Urbana, University of Illinois, Ph.D. thesis, 292 p.
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.
Logan, W. N., 1930, The mineral fuel resources of Indiana: Indiana Year Book for 1929, p. 161-171.
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.
Wanless, H. R., 1939, Pennsylvanian correlations in the Eastern Interior and Appalachian coalfields: Geological Society of America Special Paper 17, 130 p.
Wier, C. E., and Gray, H. H., 1961, Geologic map of the Indianapolis 1° x 2° quadrangle, Indiana and Illinois, showing bedrock and unconsolidated deposits: Indiana Geological Survey Regional Geologic Map, Indianapolis Sheet.
For additional information contact:
Nancy Hasenmueller (firstname.lastname@example.org)Date last revised: October 31, 2017