Type locality: The name "Bucktown Coal Member" (Dugger Formation) was proposed by Wier in an unpublished manuscript and was first published by Burger and Wier (1970), who designated a type section in sec. 1, T. 6 N., R. 8 W., near Bucktown in Sullivan County, Indiana (Burger, Wier, and Hasenmueller, 1986).
History of usage:
The identification of this coal and the underlying unnamed coal has been the source of some confusion (Burger, Wier, and Hasenmueller, 1986). Ashley (1899, p. 91), although giving no specific section, designated coal beds above Coal V (now the Springfield Coal Member) and below Coal VI (Hymera Coal Member) as Coal Va and Coal Vb. Logan (1922, p. 627) recognized two thin beds of coal above the Springfield Coal Member but said that "the upper coal is generally thicker and is designated as Coal Va." Wier (1951) and Kottlowski (1954) did not find the lower coal in the area of the Linton and Dugger quadrangles, so the upper coal was called Coal Va. Wier (1953) and Wier and Stanley (1953) then recognized Coal Va as the lower coal, which lies between the Alum Cave and Antioch Limestone Members, and Coal Vb as the upper coal, which lies above the Antioch Limestone Member. Burger and Wier (1970) noted that this lower coal could be recognized in a few exposures as a separate and distinct unit, but did not name it because of lack of information on its distribution.
The Bucktown coal ranges from 0.1 to 4.0 ft (0.03 to 1.2 m) and averages 1.2 ft (0.4 m) in thickness. In places, it contains a shale parting as much as 11 ft (3.4 m) thick (Friedman, 1961). The coal lies stratigraphically 10 to 67 ft (3 to 20 m) above the Springfield Coal Member of the Petersburg Formation. In Vermillion and Vigo Counties this shale also contains numerous shells of the conchostracan Leaia tricarinata (Burger, Wier, and Hasenmueller, 1986).
The Bucktown Coal Member is generally overlain by a dark-gray shale that contains sideritic bands (Burger, Wier, and Hasenmueller, 1986).
Although he did not use the name “Bucktown Coal Member,” Powell (1968) extended recognition of Coal Vb into Vermillion County, Indiana (Burger, Wier, and Hasenmueller, 1986). The Bucktown has been correlated with the Briar Hill, formerly 5A, Coal Member of the Carbondale Formation in Illinois (Hopkins and Simon, 1975). In their study of the conodont biostratigraphy of a shale lens overlying the Bucktown Coal Member in Pike County, Indiana, Zimmerman, Brown, and Rexroad (2013) noted that there was insufficient data for regional correlations.
Regional Indiana usage:
Illinois Basin (COSUNA 11)
Bucktown Coal Member (Vb), Coal Va, Coal Vb
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.
Ashley, G. H., 1899, The coal deposits of Indiana: Indiana Department of Geology and Natural Resources Annual Report 23, p. 1–1,573.
Burger, A. M., and Wier, C. E., 1970, Bucktown Coal Member (Vb), 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. 27–28.
Burger, A. M., Wier, C. E., and Hasenmueller, N. R., 1986, Bucktown Coal 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. 23–24.
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, M. E., and Simon, J. A., 1975, Pennsylvanian System, in Willman, H. B., Atherton, Elwood, Buschbach, T. C., Collinson, Charles, Frye, J. C., Hopkins, M. E., Lineback, J. A., and Simon, J. A., Handbook of Illinois stratigraphy: Illinois State Geological Survey Bulletin 95, p. 163–201.
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 Publication No. 21, pt. 5, p. 571–1,058.
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.
Zimmerman, Alexander, Brown, L. M., and Rexroad, C. B., 2013, Conodont biostratigraphy of a shale lens overlying the Bucktown Coal Member of the Dugger Formation (Pennsylvanian, Desmoinesian), Pike County, Indiana: Indiana Academy of Science Proceedings, v. 122, no. 1, p. 27–34.
For additional information, contact:
Nancy Hasenmueller (firstname.lastname@example.org)Date last revised: July 28, 2017