Cohn Coal Member
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
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