Kimmswick Subgroup

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Lithostratigraphy: Ottawa Limestone Megagroup >>Galena Group >>Kimmswick Subgroup
Chronostratigraphy: Paleozoic Erathem >>Ordovician System >>Champlainian Series >>Trentonian Stage
Allostratigraphy: Tippecanoe Sequence

The Kimmswick Subgroup below has been deprecated. Current formal usage is at the Formation level, as Kimmswick Limestone. A more complete update to this entry is in progress.
“Trenton” is an informal name associated with the Kimmswick Limestone.

Primary source

Willman, H. B., Elwood Atherton, T. C. Buschbach, Charles Collinson, John C. Frye, M. E. Hopkins, Jerry A. Lineback, and Jack A. Simon, 1975, Handbook of Illinois Stratigraphy: Illinois State Geological Survey Bulletin 95, 261 p.

Contributing author(s)

H. B. Willman and T. C. Buschbach


Original description

The Kimmswick Subgroup (Ulrich, 1904, p. 111; Templeton and Willman, 1963, p. 114).


The Kimmswick Subgroup is named for Kimmswick, Jefferson County, Missouri.

Other names


Type section

Type location

The type section of the Kimmswick Subgroup is in a quarry about a mile west of Kimmswick on the north side of Rock Creek just west of the mouth of Black Creek (approximately SE NE 18, 42N-6E).

Type author(s)

Type status

Reference section

Reference location

Reference author(s)

Reference status

Stratigraphic relationships

Extent and thickness

The Kimmswick Subgroup occurs throughout the area of the Galena Group. It is about 250 feet thick in northern Illinois, thins rapidly in an east-west belt through the central part of the state, and it is only 90-125 feet thick in most of the southern half of the state.


The Kimmswick Subgroup consists of the dominantly pure limestone and dolomite formations that compose the middle part of the Galena Group. It excludes the shaly strata of the Dubuque Formation at the top and the shaly formations of the Decorah Subgroup at the base. It is dominantly limestone in the southern two-thirds of the state and dolomite north of there. It is subdivided into the basal Dunleith Formation, which contains some argillaceous beds and is medium bedded and generally cherty, and the Wise Lake Formation, which is pure, massive, and not cherty. Only the Dunleith Formation is present in the Kimmswick type locality because the Wise Lake is truncated by the Cincinnatian Series south of the belt through the central part of the state where the Galena Group thins.




Well log characteristics


Age and correlation

Environments of deposition

Economic importance



TEMPLETON, J. S., and H. B. WILLMAN, 1963, Champlainian Series (Middle Ordovician) in Illinois: Illinois State Geological Survey Bulletin 89, 260 p.
ULRICH, E. O., 1904, in E. R. Buckley and H. A. Buehler, Quarrying industry of Missouri: Missouri Bureau of Geology And Mines, v. 2, 371 p.

ISGS Codes

Stratigraphic Code Geo Unit Designation