Age:

Devonian and Mississippian

Type designation:

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).

Description:

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).

This unit includes the upper part of the Blackiston Formation, all of the Sanderson Formation (including the Falling Run Member), the Underwood and Henryville Formations, and the Jacobs Chapel Shale of Campbell (1946) (Hasenmueller, 1986). The latter four units named are recognized as beds in the upper part of the Clegg Creek Member (Lineback, 1970; Hasenmueller, 1986). In ascending order they are (1) the Falling Run Bed - 0.2 ft (0.06 m) of ellipsoidal or spherical phosphatic nodules; (2) the Underwood Bed - 0.4 ft (0.1 m) of greenish-gray shale containing many conodonts and scolecodonts; (3) the Henryville Bed - 0.4 to 1.7 ft (0.1 to 0.5 m) of carbon-rich fissile shale containing conodonts, phosphatic brachiopods, and plants; and (4) the Jacobs Chapel Bed - greenish-gray calcareous glauconitic mudstone or shale, 0.2 to 0.6 ft (0.06 to 0.18 m) thick on outcrop (Hasenmueller, 1986).

The Clegg Creek Member is about 40 ft (12 m) thick in Jackson, Scott, and Clark Counties and thins southward to 22 ft (6.7 m) in Harrison County (Hasenmueller, 1982). The member is as thick as 45 ft (13.7 m) in Posey County (Hasenmueller and others , 1994, p. 19).

Boundaries:

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).

Correlations:

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).

The Upper Devonian biostratigraphic marker Protosalvinia (Foerstia) is found about 20 ft (6 m) above the base of the Clegg Creek Member in southern Indiana, and on the basis of the position of Protosalvinia the Clegg Creek Member of Indiana was correlated tentatively with part of the Antrim Shale of the eastern part of the Michigan Basin, the Huron Member of the Ohio Shale of Ohio and northeastern Kentucky, and the upper part of the Gassaway Member of the Chattanooga Shale in Tennessee (Hasenmueller and others, 1983; Hasenmueller, 1986). Over and others (2009) discuss the distribution of Protosalvinia and associated conodonts of the Upper trachytera Zone in Upper Devonian stratigraphic units in the eastern United States. Over and others (2013) noted that Bispathodus aculeatus aculeatus, Branmehla bohlenana, Br. inornata, Cryptotaxis culminidirecta, Palmatolepis glabra ssp., Pa. gracilis gracilis, and Protognathodus sp. were recovered from the upper Clegg Creek below the Falling Run Bed and are indicative the Devonian praesulcata Zone.

Regional Indiana usage:

Illinois Basin (COSUNA 11)
Supergroup: none
Group: none
Formation: New Albany Shale
Member: Clegg Creek Member
Illinois Basin Margin (COSUNA 12)
Supergroup: none
Group: none
Formation: New Albany Shale
Member: Clegg Creek Member
Cincinnati Arch (COSUNA 13)
Supergroup: none
Group: none
Formation: New Albany Shale
Member: Clegg Creek Member
Kankakee Arch (COSUNA 14)
Supergroup: none
Group: none
Formation: New Albany Shale
Member: Clegg Creek Member

Misc/Abandoned Names:

None

Geologic Map Unit Designation:

MDnacc

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 features in Indiana.

Major tectonic features that affect bedrock geology in Indiana.

References:

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 (7^th 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.

Lineback, J. A., 1970, Stratigraphy of the New Albany Shale in Indiana: Indiana Geological Survey Bulletin 44, 73 p.

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.

Rexroad, C. B., 1969, Conodonts from the Jacobs Chapel Bed (Mississippian) of the New Albany Shale in southern Indiana: Indiana Geological Survey Bulletin 41, 55 p.

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.