Type locality: The name “Fulda Limestone” was used by Franklin and Wanless (1944, p. 88-89) for a limestone exposed along the road between Fulda and New Boston in eastern Spencer County, Indiana. Their stated type locality is in the S½SW¼ sec. 33, T. 4 S., R. 4 W. (Hutchison, 1970; Shaver, 1986). Shaver (1986) noted that this locality has never been re-verified.
History of usage:
Revised rank: Thompson and Shaver (1964) assigned the Fulda member rank in the upper part of the Mansfield Formation (Hutchison, 1970; Shaver, 1986).
The Fulda Bed consists of limestone that is dark, dense, argillaceous, and hard (Shaver, 1986). This limestone is 2.5 ft (0.8 m) thick in the type locality (Franklin and Wanless, 1944), but it ranges from a probable nondepositional 0 to about 2.5 ft (0.8 m) (Shaver, 1986). Shaly limestone and a few inches of shale split are present in some places. The Fulda Bed generally lies 10 to 15 ft (3.0 to 4.6 m) below the Ferdinand Bed and about 50 ft (15 m) below the top of the Mansfield Formation (Shaver, 1986).
It is underlain by gray shale and also in some places by coal and siltstone; it is overlain by gray shale and other clastic rocks. Both contacts are thought to be conformable (Shaver, 1986).
As a classificatory unit, the Fulda is flawed by the uncertainty surrounding its type exposure and, therefore, its type stratigraphic position (Shaver, 1986). The present application of this term, however, extends to the limestone that Franklin and Wanless (1944) described as being 13 ft (4.0 m) below their Grandview Limestone (Ferdinand Bed here) (Shaver, 1986). This is also the application advocated by Hutchison (1959) (Shaver, 1986). Many exposures of the Fulda equivalent are known in Hancock County, Kentucky, adjacent to Spencer County, Indiana, but there it is simply called the lower bench of the Lead Creek Limestone Member (Shaver, 1986). The Fulda equivalent probably extends even farther south, however, to the lower of two limestones exposed near Morgantown in Butler County, Kentucky, and described by Thompson, Shaver, and Riggs (1959) (Shaver, 1986). North of Spencer County, Indiana, the Fulda has not been recognized with certainty, and single ledges of upper Mansfield limestones as far north as Warren County, Indiana, should be simply called the Lead Creek Limestone Member (Shaver and Smith, 1974, p. 9; Shaver, 1986). In some places the Fulda contains an abundant microfauna representing the ostracod Zone of Amphissites rothi and the fusulinid Zone of Profusulinella, which have far-reaching meaning for correlating the Fulda and Lead Creek rocks in general with rocks of late Bashkirian age (global scale) and late Morrowan age (North American scale) in many parts of the world (Shaver, 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.
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.
Hutchison, H. C., 1970, Fulda Limestone 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. 60-61.
Shaver, R. H., 1986, Fulda Bed, 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. 49-50.
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.
Thompson, M. L., and Shaver, R. H., 1964, Early Pennsylvanian microfaunas of the Illinois Basin: Illinois State Academy of Science Transactions, v. 67, no. 1, p. 1-23.
Thompson, M. L., Shaver, R. H., and Riggs, A. E., 1959, Early Pennsylvanian fusulinids and ostracods of the Illinois Basin: Journal of Paleontology, v. 33, p. 771-781.
For additional information, contact:
Nancy Hasenmueller (firstname.lastname@example.org)Date last revised: November 22, 2016