Type area: The Mansfield Formation was originally named the "Mansfield Sandstone" by Hopkins (1896, p. 199-200) for rocks exposed at Mansfield, Parke County, Indiana (Hutchison, 1970; Hutchison and Hasenmueller, 1986).
History of usage:
Cumings (1922, p. 527-528) amended the Mansfield to include all the rocks between the base of the Pennsylvanian System and the base of the Lower Block Coal Member (Hutchison, 1970; Hutchison and Hasenmueller, 1986).
The lowermost part of the Mansfield commonly consists of sandstone, generally cross bedded and containing a quartz-pebble and chert conglomerate in places, but it also includes dark carbonaceous shale in many places (Hutchison, 1970; Hutchison and Hasenmueller, 1986). The quartz-pebble conglomerate is also found in higher parts of the formation (Hutchison, 1970; Hutchison and Hasenmueller, 1986).
North of southern Parke County the Lower Block Coal Member (Brazil Formation) is absent or unidentifiable, so that it is nearly impossible to separate the Brazil and Mansfield Formations; in southern Indiana, in Daviess (Hutchison, 1971), Dubois (Hutchison, 1964), and Spencer (Hutchison, 1959) Counties, coal beds believed to be the equivalent of the block coals are present over most of the area but are difficult to distinguish from coals in the upper Mansfield (Hutchison and Hasenmueller, 1986).
The rocks assigned to the Mansfield Formation are equivalent to the Caseyville Formation and the lower part of the Tradewater Formation of Illinois and western Kentucky (The Tri-State Committee on Correlation of the Pennsylvanian System in the Illinois Basin, 2001), part of what has commonly been called the Pottsvillian Series of the Appalachian area, and to the Morrowan Series of the Midcontinent area (Hutchison and Hasenmueller, 1986). The Hindostan flora was described by Read (1947) as early Pottsvillian in age (Hutchison, 1970; Hutchison and Hasenmueller, 1986). Unnamed Mansfield limestones in Parke County are in the ostracod Zone of Amphissites rothi, and unnamed Mansfield limestones near Troy and Cannelton, Spencer and Perry Counties, contain the fusulinid Profusulinella, the Amphissites rothi fauna, and the ostracod Cavellinella casei, all of which are thought to indicate a Morrowan age (Hutchison, 1970; Hutchison and 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.
Ashley, G. H., 1899, The coal deposits of Indiana: Indiana Department of Geology and Natural Resources Annual Report 23, p. 1-1,573.
Cox, E. T., 1876, Seventh annual report of the geological survey of Indiana, made during the year 1875: Indianapolis, Indiana, 601 p.
Cumings, E. R., 1922, Nomenclature and description of the geological formations of Indiana, in Logan, W. N., Cumings, E. R., Malott, C. A., Visher, S. S., Tucker, W. M., Reeves, J. R., and Legge, H. W., Handbook of Indiana geology: Indiana Department of Conservation Publications 21, pt. 4, p. 403-570.
Franklin, D. W., and Wanless, H. R., 1944, Pennsylvanian stratigraphy of part of southern Indiana: Illinois State Academy of Science Transactions, v. 37, p. 85-92.
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.
Hopkins, T. C., 1896, The Carboniferous sandstones of western Indiana an economic report on the sandstones of a portion of western Indiana, accompanied by two atlas sheets showing the outcrops and distribution of the sandstone: Indiana Department of Geology and Natural Resources Annual Report 20, p. 186-327.
Hutchison, H. C., 1970, Mansfield Formation, in Shaver, R. H., Burger, A. M., Gates, G. R., Gray, H. H., Hutchison, H. C., Keller, S. J., Patton, J. B., Rexroad, C. B., Smith, N. M., Wayne, W. J., and Wier, C. E., Compendium of rock-unit stratigraphy in Indiana: Indiana Geological Survey Bulletin 43, p. 102-105.
Hutchison, H. C., and Hasenmueller, W. A., 1986, Mansfield Formation, 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. 86-88.
Lesley, Joseph, 1862, Report of Prof. Lesley, in Owen, Richard, Report of a geological reconnaissance of Indiana, made in the years 1859 and 1860: Indianapolis, H. H. Dodd and Co., p. 343-344.
Logan, W. N., 1922, Economic geology of Indiana, in Logan, W. N., Cumings, E. R., Malott, C. A., Visher, S. S., Tucker, W. M., Reeves, J. R., and Legge, H. W., Handbook of Indiana geology: Indiana Department of Conservation Publications 21, pt. 5, p. 571-1,058.
Owen, D. D., 1859, Report of a geological reconnaissance of the State of Indiana made in the year 1837, pt. 1: Indianapolis, John C. Walker, State Printer, 63 p.
Read, C. B., 1947, Pennsylvanian floral zones and floral provinces: Journal of Geology, v. 55, p. 271-279.
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.
The Tri-State Committee on Correlation of the Pennsylvanian System in the Illinois Basin, 2001, Toward a more uniform stratigraphic nomenclature for rock units (formations and groups) of the Pennsylvanian System in the Illinois Basin: Indiana Geological Survey, Illinois Basin Consortium Illinois Basin Studies 5, 26 p.
For additional information, contact:
Nancy Hasenmueller (firstname.lastname@example.org)Date last revised: April 13, 2017