Devonian and Mississippian
Type section: The Clegg Creek Member of the New Albany Shale was named by Lineback (1968, 1970) for exposures along a road cut on Indiana Highway 160, 2 miles (3.2 km) southeast of Henryville, Clark County (N¼E¼ lot 240, Clark's Grant) (Otisco quadrangle) (Hasenmueller, 1986). The name was taken from a tributary to Silver Creek 2 miles (3.2 km) from the type section (Hasenmueller, 1986).
The Clegg Creek Member is characterized by brownish-black to black, finely laminated pyritic shale rich in organic matter (Lineback, 1968, 1970; Hasenmueller, 1986). The Clegg Creek contains the highest concentrations of organic material in the New Albany Shale (Hasenmueller, 1982; Hasenmueller, 1986). There are a few greenish-gray shale or mudstone beds and phosphatic nodules near the top of the Clegg Creek Member (Hasenmueller, 1986).
The Clegg Creek Member overlies the Camp Run Member of the New Albany Shale. It underlies the Ellsworth Member of the New Albany Shale, Rockford Limestone, or Borden Group (Hasenmueller and others, 1994).
Conodont biostratigraphy indicates that the Clegg Creek Member of the New Albany Shale is of Late Devonian (Famennian) and Early Mississippian (Kinderhookian) age (Sandberg, Hasenmueller, and Rexroad, 1994). The Underwood Bed of the Clegg Creek bears a conodont fauna that is typical of the Siphonodella sulcata Assemblage Zone, which is Kinderhookian in age, and the Devonian-Mississippian boundary is at or just below the base of this bed (Hasenmueller, 1986). That part of the Clegg Creek Member below the Falling Run Bed is equivalent to the upper part of the Grassy Creek Shale, the Saverton Shale, and the Louisiana Limestone of Illinois (Lineback, 1970; Hasenmueller, 1986). The Underwood, Henryville, and Jacobs Chapel Beds of the Clegg Creek contain conodonts indicative of the cuI division of the German standard and part of the cuII division (Mississippian) and are equivalent to the Hannibal Shale of Missouri (Lineback, 1970; Hasenmueller, 1986). The Jacobs Chapel Bed correlates approximately with the middle and upper parts of the Hannibal and probably lies within the Siphonodella duplicata s.s. and the S. quadruplicata Assemblage Zones (Rexroad, 1969; Hasenmueller, 1986).
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.)
COSUNA areas and numbers that approximate regional bedrock outcrop patterns and major structural featuers in Indiana.
Major tectonic features that affect bedrock geology in Indiana.
Campbell, Guy, 1946, New Albany Shale: Geological Society of America Bulletin, v. 57, p. 829-908.
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.
Hasenmueller, N. R., 1982, Resource assessment of the New Albany Shale (Devonian and Mississippian) in southeastern Indiana–preliminary report, in Eastern Oil Shale Symposium Proceedings, 1981: Lexington, University of Kentucky and Institute for Mining and Minerals Research, p. 173-180.
Hasenmueller, N. R., 1986, Clegg Creek 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. 29-30.
Hasenmueller, N. R., Boberg, W. S., Lumm, C. B., Frankie, W. T., Hamilton-Smith, T., and Comer, J. B., 1994, Stratigraphy, in Hasenmueller, N. R., and Comer, J. B., eds., Gas potential of the New Albany Shale (Devonian and Mississippian) in the Illinois Basin: Indiana Geological Survey, Illinois Basin Consortium Illinois Basin Studies 2, p. 13-22.
Hasenmueller, N. R., Kepferle, R. C., Matthews, R. D., and Pollock, Don, 1983, Foerstia (Protosalvinia) in Devonian shales of the Appalachian, Illinois, and Michigan Basins, eastern United States, in Eastern Oil Shale Symposium Proceedings, 1983: Lexington, University of Kentucky and Institute for Mining and Minerals Research, p. 41-58.
Lineback, J. A., 1968, Subdivisions and depositional environments of New Albany Shale (Devonian-Mississippian) in Indiana: American Association of Petroleum Geologists Bulletin, v. 52, p. 1,291-1,303.
Over, D. J., Evans, S. D., Day, J., and Hasenmueller, N. R., 2013, The Devonian/Carboniferous boundary and the holotype of Siphonodella sulcata (Huddle 1934) in upper New Albany Shale, Illinois Basin, southern Indiana [abs.]: Geological Society of America Abstracts with Programs, v. 45, no. 7, p. 529; Geological Society of America Web page, https://gsa.confex.com/gsa/2013AM/webprogram/Paper226226.html, date accessed September 22, 2014.
Over, D. J., Lazar, Remus, Baird, G. C., Schieber, Juergen, and Ettensohn, F. R., 2009, Protosalvinia Dawson and associated conodonts of the Upper trachytera Zone, Famennian, Upper Devonian, in the eastern United States: Journal of Paleontology, v. 83, p. 70-79.
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.
For additional information, contact:
Nancy Hasenmueller (firstname.lastname@example.org)Date last revised: June 22, 2017