Age:Pennsylvanian Type designation:Type section: NE¼SE¼NW¼ sec. 24, T. 8 N., R. 8 W., near Antioch Church, Sullivan County, Indiana (Burger, 1970; Burger and Hasenmueller, 1986). History of usage:Informal name: The name “Antioch Limestone Member” (of the Dugger Formation) was first proposed by Wier in an unpublished manuscript (Burger and Hasenmueller, 1986).
Description:The Antioch Limestone Member consists of a conglomeratic limestone 6.4 ft (2.0 m) thick (Burger and Hasenmueller, 1986). This unit lies 2 ft (0.6 m) below the Bucktown Coal Member of the Dugger Formation and 20 ft (6.1 m) above the Alum Cave Limestone Member. In places, a thin unnamed coal lies between the Alum Cave and Antioch limestones, but it is not present in the type area (Burger and Hasenmueller, 1986). The Antioch has few specifically identifiable fossils but does have partly broken and recrystallized remains of gastropods, ostracods, brachiopods, and crinoid columnals (Burger and Hasenmueller, 1986).
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Regional Indiana usage:
Illinois Basin (COSUNA 11)
Misc/Abandoned Names:Upper Alum Cave Limestone Geologic Map Unit Designation:*da 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: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. 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. |
For additional information, contact:
Nancy Hasenmueller (hasenmue@indiana.edu)Date last revised: June 9, 2023