Age:

Pennsylvanian

Type designation:

Type section: The name, defined by Wier (in an unpublished manuscript and in 1970) as the St. Wendel Sandstone Member of the Bond Formation, was taken from St. Wendel in Posey County, Indiana, near the Vanderburgh county line (Wier, 1970, 1986). Wier (1970) designated the type section in the NW¼NW¼SE¼, sec. 19, T. 5 S., R. 11 W.

History of usage:

The name “St. Wendells” was first published as a formation name in a columnar section by Logan (1932), who apparently followed the terminology and spelling used in C. A. Malott's field notes and later published (Malott, 1948, p. 132) and who also used the term “Bufkin Formation” for probably equivalent rocks (Wier, 1970, 1986).

Description:

The St. Wendel Sandstone Member of the Bond Formation is a medium-grained micaceous massive sandstone commonly ranging from 45 to 55 ft (14 to 17 m) in thickness (Wier, 1986). In some places it directly overlies the Carthage Limestone Member, and in other places it is separated from the Carthage by shale (Wier, 1986). It is well exposed in bluffs in northern Gibson County and in Knox County (Wier, 1970, 1986). Northward in Sullivan County the stratigraphic position of the St. Wendel is occupied by shale or thin beds of sandstone and shale (Wier, 1970, 1986).

Regional Indiana usage:

Illinois Basin (COSUNA 11)
Supergroup: none
Group: McLeansboro Group
Formation: Bond Formation
Member: St. Wendel Sandstone Member

Misc/Abandoned Names:

Bufkin Formation

Geologic Map Unit Designation:

*bsw

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:

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.

Logan, W. N., 1932, The subsurface strata of Indiana: Indiana Department of Conservation Publication No. 108, 790 p.

Malott, C. A., 1948, The geology of the Dicksburg Hills, Knox County, Indiana: Indiana Academy of Science Proceedings, v. 57, p. 125–141.

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.

Wier, C. E., 1970, St. Wendel Sandstone Member, 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. 149–150.

Wier, C. E., 1986, St. Wendel Sandstone 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. 128.