Type section: The Muscatatuck Group was named for its many exposures along the forks and tributaries of the Muscatatuck River, particularly in Jefferson and Jennings Counties, southeastern Indiana (Shaver, 1974, p. 3-6; Droste and Shaver, 1986). The type section is an exposure along the north bluff of Big Camp Creek, Jefferson County (NE¼NE¼SW¼ sec. 13, T. 4 N., R. 8 E.), there embracing the Jeffersonville and North Vernon Limestones (Droste and Shaver, 1986).
History of usage:
Shaver (1974) proposed the name “Muscatatuck Group” to include in Indiana all the so-called Middle Devonian carbonate rocks or the Middle Devonian limestone (Limestone) of common usage that lie stratigraphically between the New Harmony Group (Lower Devonian) and the Devonian black shale units above (Droste and Shaver, 1986).
Several kinds of carbonate and evaporite lithologies make up the Muscatatuck Group (Droste and Shaver, 1986). The most common are: drab-colored fine-grained sandy dolostone or dolomitic quartz sandstone, which is generally found lowest in the group but in other positions in some places; (2) brown granular vuggy dolostone, concentrated in, but not confined to, the Geneva and Milan Center Dolomite Members; (3) light-colored to dark limestones that are shaly to pure and granular and conspicuously fossiliferous and that exhibit features generally ascribed to normal-marine depositional regimes, these rocks typifying parts of the Jeffersonville Limestone and much of the North Vernon Limestone and the Traverse Formation; (4) variously colored dense, including lithographic, to fine-grained, commonly laminated dolostones and dolomitic limestones that exhibit other sedimentary features generally ascribed to penesaline or hypersaline depositional regimes and that especially typify parts of the Jeffersonville Limestone and much of the Detroit River Formation; and (5) white to pale-blue cryptocrystalline to coarsely granular and fibrous anhydrite and gypsum, which are found in lower and upper Detroit River rocks (Droste and Shaver, 1986).
In a few southwesternmost Indiana counties in the deeper part of the Illinois Basin, the Muscatatuck overlies carbonate rocks of the New Harmony Group (Lower Devonian) conformably (Droste and Shaver, 1986). Elsewhere the Muscatatuck has mostly an overlapping, truncating relationship with Silurian rocks that range stratigraphically downward from the youngest rocks in the Salina Group (Wabash Formation) to within the Salamonie Dolomite (middle Niagaran) (Droste and Shaver, 1986). The magnitude of truncation increases in a southeasterly direction (Droste and Shaver, 1986).
The Muscatatuck Group is mostly Middle Devonian in age (Erian, North American standard; Eifelian and Givetian, global standard) as shown by different groups of index fossils and as keyed in part by the relationships of the Tioga Bentonite Bed (Droste and Shaver, 1986). The lowest part of the Muscatatuck is very likely Early Devonian (Emsian, global standard Ulsterian, North American standard) (Droste and 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.
Boucot, A. J., and Johnson, J. G., 1968, Stratigraphy and paleontology of the Bois Blanc Formation in New York: U.S. Geological Survey Professional Paper 584-B, p. B1-B27.
Conkin, J. E., and Conkin, B. M., 1980, Handbook of strata and fossils at the Falls of the Ohio: Louisville, Ky., University of Louisville Studies in Paleontology and Stratigraphy, 27 p.
Droste, J. B., and Shaver, R. H., 1975, The Jeffersonville Limestone (Middle Devonian) of Indiana—stratigraphy, sedimentation, and relation to Silurian reef-bearing rocks: American Association of Petroleum Geologists Bulletin, v. 59, p. 393-412.
Droste, J. B., and Shaver, R. H., 1986, Muscatatuck Group, 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. 99-100.
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.
Lazor, J. D., 1971, Petrology and subsurface stratigraphy of the Traverse Formation (Middle Devonian) in northern Indiana: Bloomington, Indiana University, Ph.D. thesis, 143 p.
Oliver, W. A., Jr., 1976, Noncystimorph colonial rugose corals of the Onesquethaw and lower Cazenovia Stages (Lower and Middle Devonian) in New York and adjacent areas: U.S. Geological Survey Professional Paper 869, 156 p.
Orr, R. W., 1964, Conodonts from the Devonian Lingle and Alto Formations of southern Illinois: Illinois State Geological Survey Circular 361, 28 p.
Orr, R. W., 1969, Stratigraphy and correlation of Middle Devonian strata in the Logansport Sag, north-central Indiana: Indiana Academy of Science Proceedings, v. 78, p. 333-341.
Orr, R. W., and Pollock, C. A., 1968, Reference sections and correlation of Beechwood Member (North Vernon Limestone, Middle Devonian) of southern Indiana and northern Kentucky: American Association of Petroleum Geologists Bulletin, v. 52, p. 2,257-2,262.
Perkins, R. D., 1963, Petrology of the Jeffersonville Limestone (Middle Devonian) of southeastern Indiana: Geological Society of America Bulletin, v. 74, p. 1,335-1,354.
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.
Shaver, R. H., Doheny, E. J., Droste, J. B., Lazor, J. D., Orr, R. W., Pollock, C. A., and Rexroad, C. B., 1971, Silurian and Middle Devonian stratigraphy of the Michigan Basin–a view from the southwest flank, in Forsyth, J. L., Geology of the Lake Erie islands and adjacent shores: Michigan Basin Geological Society Guidebook, p. 37-59.
Sparling, D. R., 1983, Conodont biostratigraphy and biofacies of lower Middle Devonian limestones, north-central Ohio: Journal of Paleontology, v. 57, p. 825-864.
Stumm, E. C., 1964, Silurian and Devonian corals of the Falls of the Ohio: Geological Society of America Memoirs 93, 184 p.
For additional information, contact:
Nancy Hasenmueller (firstname.lastname@example.org)Date last revised: January 12, 2021