Age:Pennsylvanian Type designation:Type section: The name "French Lick" was first applied to an exposure of coal in a whetstone quarry said to be in the SW¼NW¼ sec. 4, T. 2 N., R. 2 W., near French Lick, Orange County, Indiana (Franklin, 1939, p. 9; Hutchison, 1970; Hutchison and Hasenmueller, 1986). Gray, Jenkins, and Weidman (1960, p. 26-27), stated that Franklin's intended type section is probably in the NE¼NE¼ sec. 5, T. 1 N., R. 2 W. (Hutchison, 1970; Hutchison and Hasenmueller, 1986). History of usage:Revised rank: This coal was accorded member status in the Mansfield Formation by Gray, Jenkins, and Weidman (1960, p. 26-27) (Hutchison, 1970; Hutchison and Hasenmueller, 1986). Description:The French Lick Coal Member was commercially mined in the type area and was described by Franklin (1939) as bright, blocky, 2.4 ft (0.7 m) thick, and having no partings (Hutchison, 1970; Hutchison and Hasenmueller, 1986). Stratigraphically, the coal lies immediately below or close to the so-called “Hindostan Whetstone Beds” and 40 to 60 ft (12 to 18 m) below the Pinnick Coal Member (Hutchison, 1970; Hutchison and Hasenmueller, 1986). Ashley (1899, p. 1086) reported its maximum thickness as 1.8 ft (0.6 m).
Boundaries:The roof of the coal is generally thin carbonaceous shale that is overlain by sandy siltstone. The floor is underclay (Hutchison, 1970; Hutchison and Hasenmueller, 1986). |
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Regional Indiana usage:
Illinois Basin (COSUNA 11)
Misc/Abandoned Names:Coal I Geologic Map Unit Designation:*mfl 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:Ashley, G. H., 1899, The coal deposits of Indiana: Indiana Department of Geology and Natural Resources Annual Report 23, p. 1–1,573. Franklin, D. W., 1939, Lithologic and stratigraphic study of the Lower Pennsylvanian strata, Orange County, Indiana: Urbana, University of Illinois, master's thesis, 49 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. 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