Type locality: In 1931 Malott (p. 224 and fig. 2) noted that the shale was "called the Indian Springs shale after the outcrop 0.25 miles northwest of the village" of that name in Martin County, Indiana (Gray, 1986).
History of usage:
The term “Indian Springs Shale” was proposed (without documentation) in 1920 by Malott and Thompson (p. 522) (Gray, 1986).
The member commonly consists of 3 to 14 ft (1 to 4 m) of gray fossiliferous shale and interbedded thin limestone underlain by 3 to 10 ft (1 to 3 m) of varicolored shale and siltstone (Gray, 1986).
The fauna is consistent with that reported for the upper part of the Fraileys Shale and for the Haney Limestone elsewhere in the Illinois Basin (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.
Gray, H. H., 1986, Indian Springs Shale 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. 62.
Gray, H. H., and Powell, R. L., 1965, Geomorphology and groundwater hydrology of the Mitchell Plain and Crawford Upland in southern Indiana: Indiana Geological Survey Field Conference Guidebook 11, 26 p.
Gray, H. H., Dawson, T. A., McGregor, D. J., Perry, T. G., and Wayne, W. J., 1957, Rocks associated with the Mississippian-Pennsylvanian unconformity in southwestern Indiana: Indiana Geological Survey Field Conference Guidebook 9, 42 p.
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.
Horowitz, A. S., ed., 1979, Mississippian rocks—New Albany to Indianapolis, Indiana, via Interstate 64 and Indiana Highway 37: Bloomington, Indiana, Guidebook prepared for Ninth International Congress of Carboniferous Stratigraphy and Geology, Field Trip 7, Day 4, May 20, 1979, 70 p. [mimeo.].
Kelly, S. M., 1984, Paleoeology [sic] and paleontology of the Indian Springs Shale Member, Big Clifty Formation (middle Chesterian) in south-central Indiana: Bloomington, Indiana University, Ph.D. thesis, xix + 343 p.
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.
Malott, C. A., 1952, Stratigraphy of the Ste. Genevieve and Chester formations of southern Indiana: Ann Arbor, Michigan, Edwards Letter Shop, 105 p.
Malott, C. A., and Thompson, J. D., Jr., 1920, The stratigraphy of the Chester Series of southern Indiana [abs.]: Science, new ser., v. 51, p. 521-522.
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 8, 2017