Age:

Mississippian

Type designation:

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).

At the type section the limestone is 12 ft (4 m) thick and lies 23 ft (7 m) above the Mount Pleasant Sandstone Member, then also given formational rank (Gray, 1986). The intervening blue-gray shale was unassigned. Later, Malott (1931, p. 222) asserted an equivalence to the Kinkaid Limestone of Illinois, and the name Negli Creek was abandoned (Gray, 1986). Swann (1963, p. 42-43), however, showed that the type Negli Creek represents only the basal part of the Kinkaid, and he therefore reinstated the name for the basal member of the Kinkaid Limestone (Gray, 1986). In a restudy of outcropping upper Chesterian rocks, Gray (1978, p. 12-13) assigned this member to the newly named Tobinsport Formation (Gray, 1986).

Droste and Keller (1995, p. 14) adopted the name “Negli Creek Limestone Member” for use in the subsurface of Indiana.

Description:

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.

In the subsurface, the Negli Creek is composed of light and medium shades of gray and brown limestones that are massive and sparingly to commonly fossiliferous (Droste and Keller, 1995). Less abundant is mudstone (Droste and Keller, 1995). The Negli Creek is routinely 18 to 22 ft (5 to 6.7 m) thick; however, Droste and Keller (1995) reported that it is 25 to 30 ft (7.6 to 9.1 m) thick in southwestern Posey County.

Distribution: As the lowest member of the Kinkaid Limestone, the Negli Creek Limestone Member is present in the subsurface from Gibson County southward to the Ohio River and, less continuously, eastward to Perry County (Gray, 1986; Droste and Keller, 1995, fig. 16).

Boundaries:

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.

Correlations:

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)
Supergroup: none
Group: Buffalo Wallow Group
Formation: Kinkaid Limestone
Member: Negli Creek Limestone Member
Illinois Basin (COSUNA 11)
Supergroup: none
Group: Buffalo Wallow Group
Formation: Tobinsport Formation
Member: Negli Creek Limestone Member

Misc/Abandoned Names:

None

Geologic Map Unit Designation:

Mknc

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:

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.

Droste, J. B., and Keller, S. J., 1995, Subsurface stratigraphy and distribution of oil fields of the Buffalo Wallow Group (Mississippian) in Indiana: Indiana Geological Survey Bulletin 63, 24 p.

Gray, H. H., 1978, Buffalo Wallow Group upper Chesterian (Mississippian) of southern Indiana: Indiana Geological Survey Occasional Paper 25, 28 p.

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 (7^th 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.