Age:Devonian Type designation:
Type locality: The name “Beechwood Limestone Member” of the Sellersburg Limestone was proposed by Butts (1915, p. 120) for several feet of gray thick-bedded coarse-grained crinoidal limestone exposed near Beechwood Station on the Louisville and Nashville Railroad and 1.5 miles (2.4 km) east of St. Mathews, Jefferson County, Kentucky (Droste and Shaver, 1986).
History of usage:Abandoned names: This limestone had been called the Encrinital (Encrinal, Crinoidal) Limestone of early reports and in Indiana was the restricted Sellersburg Limestone of Siebenthal (1901, p. 345-346) (Burger and Patton, 1970, p. 11).
Description:The Beechwood Member consists of light- to dark-gray and brown fine-grained to very coarse grained (calcarenitic with sparry cement) crinoidal limestone commonly containing glauconite in its upper part and black rounded phosphate grains or pebbles in its lower part; some shale is present in places; also, macrofossils, especially brachiopods, are abundant (Droste and Shaver, 1986).
Boundaries:The Beechwood overlies unconformably (Patton and Dawson, 1955, p. 42) the Silver Creek and Speed Members of the North Vernon, or North Vernon rocks not identified to member, or the Vernon Fork Member of the Jeffersonville Limestone (lower Middle Devonian) (Droste and Shaver, 1986). It is overlain by the New Albany Shale, variably conformably (Blocher Member) and unconformable (Blocher and Selmier Members) (Droste and Shaver, 1986). Correlations:The Beechwood has been correlated for more than 100 years with part of the Hamilton Group of New York principally on the basis of its brachiopods (Borden, 1874; Hall, 1879; Kindle, 1899, p. 110; Cooper and Warthin, 1942, p. 882-883, specifically the Centerfield Limestone Member of the Ludlowville Formation). Conodonts (Orr and Pollock, 1968; Orr, 1971, p. 17; Sandberg, Hasenmueller, and Rexroad, 1994) place the Beechwood in the Polygnathus varcus Zone (middle Givetian, global standard) and in close correlation with the Ludlowville Formation (upper Hamilton) of New York (Droste and Shaver, 1986.)
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Regional Indiana usage:
Illinois Basin Margin (COSUNA 12)
Misc/Abandoned Names:Carey Member, Encrinital (Encrinal, Crinoidal) Limestone, restricted Sellersburg Limestone, Swanville Formation Geologic Map Unit Designation:Dnvb 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:Borden, W. W., 1874, Report of a geological survey of Clark and Floyd Counties, Indiana: Indiana Geological Survey Annual Report 5, p. 133–189. Butts, Charles, 1915, Geology and mineral resources of Jefferson County, Kentucky: Kentucky Geological Survey, ser. 4, v. 3, pt. 2, 270 p. Cooper, G. A., and Warthin, A. S., Jr., 1942, New Devonian (Hamilton) correlations: Geological Society of America Bulletin, v. 53, p. 873–888. Droste, J. B., and Shaver, R. H., 1975, The Jeffersonville Limestone (Middle Devonian) of Indiana—stratigraphy, sedimentation, and relation to Silurian reef-bearing rocks: American Association of Petroleum Geologists Bulletin, v. 59, p. 393–412. Hall, James, 1879, The hydraulic beds and associated limestones at the Falls of the Ohio: Albany Institute Transactions, v. 9, p. 169–180. 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. Hattin, D. E., Nosow, Edmund, Perkins, R. B., Stumm, E. C., Mound, M. C., and Utgaard, John, 1961, Field excursion to the Falls of the Ohio; field trip no. 9: Geological Society of America Guidebook for Field Trips, 74th Annual Meeting, Cincinnati, Ohio, p. 295–350. Kindle, E. M., 1899, The Devonian and Lower Carboniferous faunas of southern Indiana and central Kentucky: Bulletins of American Paleontology, v. 3, no. 12, 111 p. Orr, R. W., and Pollock, C. A., 1968, Reference sections and correlation of Beechwood Member (North Vernon Limestone, Middle Devonian) of southern Indiana and northern Kentucky: American Association of Petroleum Geologists Bulletin, v. 52, p. 2,257–2,262. Sandberg, C. A., Hasenmueller, N. R., and Rexroad, C. B., 1994, Conodont biochronology, biostratigraphy, and biofacies of Upper Devonian part of New Albany Shale, Indiana: Courier-Forschungsinstitut Senckenberg, v. 168, p. 227–253. 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. Siebenthal, C. E., 1901, The Silver Creek Hydraulic Limestone of southeastern Indiana: Indiana Department of Geology and Natural Resources Annual Report 25, p. 331–389. |
For additional information, contact:
Nancy Hasenmueller (hasenmue@indiana.edu)Date last revised: June 19, 2017