Type designation:

Type area: First designated the "Detroit River Series" (Lane and others, 1909, p. 555), the rocks exposed along the Detroit River in southeastern Michigan are now referred to as the "Detroit River Group" and constituent formations in that state.

History of usage:

Extended: In Indiana the name "Detroit River Formation" was first adopted by Schneider and Keller (1970), following the outlines of Pinsak and Shaver (1964), and has since been used for all Middle Devonian rocks that lie between Silurian rocks (below) and the Traverse Formation (above) and that are north of the Kankakee and Cincinnati Arches (Droste and Shaver, 1986).


The Detroit River Formation of northern Indiana exhibits three basic lithologies or mixtures of lithologies that respectively characterize three named members and that are partial facies of one another. The generally lower interval of Detroit River rocks begins at its base with sandy dolomicrite that grades up into a series of cyclically deposited light-colored fine-grained dolostone and evaporite rocks (Droste and Shaver, 1986). These are, in ascending order in a typical cycle, light-gray massive dolomite mudstone, pale-blue anhydrite and white crystalline gypsum, pale-yellowish-brown massive dolomite mudstone, and dark-yellowish-brown laminated dolomite mudstone. This range in lithology characterizes the Grover Ditch Member (Droste and Shaver, 1986).

In a generally middle position, the Detroit River consists of dolostone that is richly colored tan and brown, fine grained, saccharoidal, vuggy, and characteristic of the Milan Center Dolomite Member (Droste and Shaver, 1986). Oolitic and pelletoidal rocks and grainstones and packstones, some obviously fossiliferous, are included. In a generally upper position, the formation consists of gray to dark-brown sublithographic and lithographic dolostone (evaporitic dolostones?) and limestones and massive to thin beds of gypsum and anhydrite (Droste and Shaver, 1986). Some carbonate sections are brecciated, and a few are cherty. These lithologies particularly characterize the Cranberry Marsh Member (Droste and Shaver, 1986).

A metabentonitic shale, 1 to a few inches (3.0 to 15.0 cm) thick and called the Tioga Bentonite Bed, is present in some subsurface sections and quarry exposures (Droste and Shaver, 1986). It has been found in all three facies described above.

Detroit River rocks extend from an eroded edge (zero thickness) along the north flank of the Kankakee and Cincinnati Arches, through a northeastward-thickening wedge that ranges in thickness along the Michigan-Indiana line from about 80 ft (24 m) to more than 160 ft (49 m) (Droste and Shaver, 1986).

Distribution: Nearly all this distribution is in the subsurface because there are thick Quaternary materials in that area and because the Traverse Formation generally overlaps the Detroit River southward, although along much of the southernmost distribution of these rocks post-Middle Devonian erosion has removed the proof of overlap (Droste and Shaver, 1986).


The Detroit River Formation unconformably overlies Silurian rocks of the Salina Group as low as the Mississinewa Shale Member (Wabash Formation) in regionally truncative fashion. It is overlain unconformably by the Traverse Formation in an overlapped manner (Droste and Shaver, 1986).


Because much of the Detroit River Formation of northern Indiana was deposited in penesaline to hypersaline conditions, normal-marine fossils of the kind used for interregional correlation in the age sense are scarce. Statements on correlation, therefore, rely mostly on physical tracing and position in the stratigraphic sequence. Nevertheless, a few conodont determinations, the Tioga Bentonite Bed, and some intertonguing of Detroit River rocks with normal-marine rocks in western Ohio and in southern Indiana (speculative; before erosion) provide keys that allow close correlations (Droste and Shaver, 1986).

Much of the Detroit River of Indiana is an updip extension of the much thicker Lucas Formation (Detroit River Group) in the deeper part of the Michigan Basin (Droste and Shaver, 1986). In Steuben County, far northeastern Indiana, the lowest Detroit River interval may correspond to parts of the Sylvania Sandstone and the Amherstburg Formation of adjacent Michigan and Ohio (Shaver, 1984). And according to Rooney (1965), the upper Detroit River evaporite section of northwestern Indiana correlates with the so-called Reed City Anhydrite of western Michigan.

The Detroit River of Indiana extends directly into most of a northwestern Ohio sequence that begins at its base with the Sylvania and the Amherstburg and extends upward through the Lucas and thence into a westward-transgressive body of normal-marine rocks made up of the Columbus and Dundee Limestones (Droste and Shaver, 1986). In this relationship, therefore, an upper part (lithographic carbonate rocks) of the Detroit River of Indiana extends into Ohio as a middle to lower part of the Dundee Limestone of Janssens (1970, figs. 1 and 7) and Sparling (1983, fig. 9 and p. 839).

Although Detroit River rocks are now physically separated (because of erosion) from the Jeffersonville Limestone of central and southern Indiana, similar lithologic sequences in each formation suggest close, almost member-by-member correlation (Droste and Shaver, 1973 and 1975; Droste and Shaver, 1986).

Conodonts have been found only sparingly in the Detroit River of Indiana and in LaPorte County include species assignable to the Polygnathus costatus (P. "webbi") Zone and that came from well below the Tioga bed. The Tioga elsewhere in the northeastern United States is known to occur at or just below the base of the Icriodus angustus Zone of Orr's (1971, p. 19-20) usage and equivalent biostratigraphic levels in the northeastern United States. (See Shaver and others, 1971, p. 54-55; Droste and Orr, 1974; and Sparling, 1983, p. 839.)

All these interrelated circumstances strongly suggest that the oldest Detroit River rocks of Indiana are as old as late Early Devonian (Emsian, global standard) and that the youngest Detroit River rocks are middle Middle Devonian (late Eifelian) in age. Close, but not necessarily exact, correlative include, therefore, the units already mentioned for Michigan, western Ohio, and southern Indiana; the Onondaga Formation of New York; the Grand Tower Limestone of Illinois; and the Jeffersonville Limestone of western Kentucky. Also, small, lower parts of the Lingle Formation of Illinois, the North Vernon Limestone of southern Indiana, the Sellersburg Limestone of western Kentucky, and the Marcellus Shale of New York may be correlatives of the uppermost Detroit River rocks as defined in Indiana.

Regional Indiana usage:

Kankakee Arch (COSUNA 14)
Supergroup: none
Group: Muscatatuck Group
Formation: Detroit River Formation
Michigan Basin (COSUNA 15)
Supergroup: none
Group: Muscatatuck Group
Formation: Detroit River Formation

Misc/Abandoned Names:


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.

See also:

Jeffersonville Limestone


Droste, J. B., and Orr, R. W., 1974, Age of the Detroit River Formation in Indiana: Indiana Geological Survey Occasional Paper 5, 5 p.

Droste, J. B., and Shaver, R. H., 1973, Middle Devonian depositional symmetry from Michigan Basin to Illinois Basin [abs.]: Geological Society of America Abstracts with Programs, v. 5, p. 311-312.

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, Detroit River Formation, 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. 35-37.

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.

Janssens, Adriaan, 1970, Middle Devonian formations in the subsurface of northwestern Indiana: Ohio Geological Survey Report of Investigations 78, 22 p.

Lane, A. C., and others, 1909, Nomenclature and subdivisions of the upper Siluric strata of Michigan, Ohio, and western New York: Geological Society of America Bulletin, v. 19, p. 553-556.

Orr, R. W., 1971, Conodonts from Middle Devonian strata of the Michigan Basin: Indiana Geological Survey Bulletin 45, 110 p.

Pinsak, A. P., and Shaver, R. H., 1964, The Silurian formations of northern Indiana: Indiana Geological Survey Bulletin 32, 87 p.

Schneider, A. F., and Keller, S. J., 1970, Geologic map of the 1° x 2° Chicago quadrangle, Indiana, Illinois, and Michigan, showing bedrock and unconsolidated deposits: Indiana Geological Survey Regional Geologic Map No. 4, Part A [bedrock units].

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.

For additional information contact:

Nancy Hasenmueller (
Date last revised: December 6, 2013