Type section: The Negli Creek Limestone Member was named and given formational rank by Malott (1925, p. 112-114, 120-121), who specified a type section on a creek of that name in Perry County (Gray, 1986.)
History of usage:
Orthography of the name is uncertain; it is spelled Neglie Creek on the Cannelton 7.5-minute topographic map, but Malott's original spelling has always been used for this unit (Gray, 1986).
The Negli Creek Limestone Member crops out at many places in southern Perry County but is not known north of the central part of that county (Gray, 1986). It is 7 to 12 ft (2 to 4 m) thick and consists of unevenly stratified fossiliferous gray to yellow-brown limestone (Gray, 1986). Commonly it is a single bed, but in some places it consists of two beds of limestone separated by thin blue-gray to green-gray shale (Gray, 1986). At the type locality and at a few other places, similar shale as much as 10 ft (3 m) thick that overlies the limestone was assigned to the Tobinsport Formation as an unnamed member by Gray (1986). Gray (1986) noted that this shale is equivalent to the lower part of the Cave Hill Shale Member of the Kinkaid Limestone in the standard Chesterian section of Swann (1963). Later, Droste and Keller (1995, p. 14) adopted the name “Cave Hill Shale Member” for use in the subsurface of Indiana.
Droste and Keller (1986, p. 12) noted that the Negli Creek is overlain conformably by the Cave Hill Member of the Kinkaid Limestone or unconformably by Pennsylvanian units.
The Negli Creek Limestone Member correlates with rocks within North American foraminiferal Zone 18 of Mamet and Skipp (1971) and within the Namurian Series (Zone E2) of European usage (Gray, 1986). On the basis of its conodont fauna, the Negli Creek was assigned to the Kladognathus-Cavusgnathus naviculus Assemblage Zone of the North American standard by Collinson, Rexroad, and Thompson (1971) (Gray, 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 features in Indiana.
Major tectonic features that affect bedrock geology in Indiana.
Collinson, Charles, Rexroad, C. B., and Thompson, T. L., 1971, Conodont zonation of the North American Mississippian: Geological Society of America Memoirs 127, p. 353–394.
Gray, H. H., 1986, Negli Creek Limestone 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. 100.
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.
Malott, C. A., 1925, The upper Chester of Indiana: Indiana Academy of Science Proceedings, v. 34, p. 103–132.
Malott, C. A., 1931, Geologic structure in the Indian and Trinity Springs locality, Martin County, Indiana: Indiana Academy of Science Proceedings, v. 40, p. 217–231.
Mamet, B. L., and Skipp, B. A., 1971, Lower Carboniferous calcareous Foraminifera–preliminary zonation and stratigraphic implications for the Mississippian of North America: Sixieme Congres International de Stratigraphie et de Geologie du Carbonifere Sheffield, 1967, Compte rendu, v. 3, p. 1,129–1,146.
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.
Swann, D. H., 1963, Classification of Genevievian and Chesterian (Late Mississippian) rocks of Illinois: Illinois State Geological Survey Report of Investigations 216, 91 p.
For additional information, contact:
Nancy Hasenmueller (firstname.lastname@example.org)Date last revised: March 27, 2017