Age:

Pennsylvanian

Type designation:

Type locality: The name “Raben Branch” was first used for exposures of a thin coal bed along the small stream of Raben Branch in the SE¼ sec. 11, T. 5 S., R. 12 W., Posey County, Indiana (Malott, 1948, p. 132; Wier, 1970; Wier and Ault, 1986).

History of usage:

This coal was formally assigned member status in the Patoka Formation by Wier (1970). Wier and Ault (1986) proposed the slightly modified name “Raben Branch Coal Member.”

Description:

The Raben Branch member, a thin coal or smut streak about an inch (0.03 m) thick lying on a thin underclay, is a persistent marker bed in Vanderburgh and Posey Counties (Wier, 1970; Wier and Ault, 1986). This unit is overlain by a thin sideritic clay containing numerous shells and imprints of the conchostracan Estheria (Wier, 1970; Wier and Ault, 1986). The Raben Branch lies 20 ft (6 m) below the Parker Coal Member and 1 to 5 ft (0.3 to 1.5 m) above the Dicksburg Hills Sandstone Member, both of the Patoka Formation (Wier, 1970; Wier and Ault, 1986).

Correlations:

The Womac Coal Member of the Modesto Formation of Illinois has been correlated with the Raben Branch by Hopkins and Simon (1975, p. 196) (Wier and Ault, 1986). In 2001, the upper part of the Modesto Formation of Illinois and the middle part of the Sturgis Formation of western Kentucky were assigned the name "Patoka Formation" by The Tri-State Committee on Correlation of the Pennsylvanian System in the Illinois Basin (2001).

Regional Indiana usage:

Illinois Basin (COSUNA 11)
Supergroup: none
Group: McLeansboro Group
Formation: Patoka Formation
Member: Raben Branch Coal Member

Misc/Abandoned Names:

None

Geologic Map Unit Designation:

*prb

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.

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.

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.

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.

Wier, C. E., 1970, Raben Branch 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. 135–136.

Wier, C. E., and Ault, C. H., 1986, Raben Branch 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. 120.