The Kankakee Arch is a geologic arch with a northwest–southeast trending axis which connects the

Cincinnati Arch The Cincinnati Arch is a broad structural uplift between the Illinois Basin to the west, the Michigan Basin to the northwest and the Appalachian Basin and Black Warrior Basin to the east and southeast. It existed as a positive topographic area du ...

to the southeast with the

Wisconsin Dome Wisconsin () is a U.S. state, state in the Upper Midwest, upper Midwestern United States. Wisconsin is the List of U.S. states and territories by area, 25th-largest state by total area and the List of U.S. states and territories by populatio ...

to the northwest. It lies beneath northeastern

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...

, northern

Indiana Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...

and southeastern

Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...

. This structural ridge lies between the

Illinois Basin The Illinois Basin is a Paleozoic depositional and structural basin in the United States, centered in and underlying most of the state of Illinois, and extending into southwestern Indiana and western Kentucky. The basin is elongate, extending app ...

to the southwest and the

Michigan Basin The Michigan Basin is a geologic basin centered on the Lower Peninsula of the U.S. state of Michigan. The feature is represented by a nearly circular pattern of geologic sedimentary strata in the area with a nearly uniform structural dip toward ...

to the northeast. The area of central Illinois began to depress by the late

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start ...

.A Summary Geologic History of the Illinois Basin, David H. Swann; 2005 The

was developing across eastern Indiana during the late

. By the Early SilurianRandall Schaetzl, Michigan State University Web the seas northwest of the Cincinnati Arch began to become shallower. By the Early Mississippian, the Kankakee arch was above sea level.Geology of Indiana; Mark J. Camp & Graham T. Richardson; Mountain Press Publishing; Missoula, MT; 1995 During the

Silurian Period The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozo ...

(420 to 405 MYA) a shallow sea spread across Indiana. This sea deposited limestones along the southwest slope of the arch. Over the arch, the depth of the deposits diminish, thus layers northeast of the arch become only across the top of the arch. As in the Silurian Period, the

Devonian Period The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, wh ...

(438 to 408 MYA) witnessed a renewal of the shallow seas after a short period when the area was above sea level. Deposition resumed with related, but significantly different

dolomite Dolomite may refer to: *Dolomite (mineral), a carbonate mineral *Dolomite (rock), also known as dolostone, a sedimentary carbonate rock *Dolomite, Alabama, United States, an unincorporated community *Dolomite, California, United States, an unincor ...

s and limestones both north and south of the shallow area of the arch.

References

{{reflist Geology of Indiana Geology of Illinois