Cohn Coal Member

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Lithostratigraphy: McLeansboro Group >>Mattoon Formation >>Cohn Coal Member
Chronostratigraphy: Paleozoic Erathem >>Pennsylvanian Subsystem >>Missourian Series
Allostratigraphy: Absaroka Sequence

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)

M. E. Hopkins and J. A. Simon

Name

Original description

The Cohn Coal Member of the Mattoon Formation (Newton and Weller, 1937, p. 18).

Derivation

Named for Cohn (now called Livingston), Clark County.

Other names

History/background

Type section

Type location

The type section consists of an exposure on the south side of Big Creek, about 2.5 miles from Livingston (NE 1, 11N-12W).

Type author(s)

Type status

Reference section

Reference location

Reference author(s)

Reference status

Stratigraphic relationships

At the type locality, it lies 22 feet above the Livingston Limestone and 12 feet below the base of the Merom Sandstone. A 16-inch thick nodular limestone containing numerous Spiroibis occurs 2 feet above the coal.

Extent and thickness

The Cohn Coal occurs in eastern Illinois, where it is generally less than 10 inches thick. At its type locality it is only 2 inches thick.

Lithology

Core(s)

Photograph(s)

Contacts

Well log characteristics

Fossils

Age and correlation

To the south in Crawford County, the Cohn Coal is correlated with a thin coal that has been mined in the vicinity of Flat Rock. In that area the Cohn Coal lies at or very near the base of the Merom Sandstone, which may have eroded the coal in some areas.

Environments of deposition

Economic importance

Remarks

References

NEWTON, W. A., and J. M. WELLER, 1937, Stratigraphic studies of Pennsylvanian outcrops in part of southeastern Illinois: Illinois State Geological Survey Report of Investigations 45, 31 p.

ISGS Codes

Stratigraphic Code Geo Unit Designation
1850
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