Historical:Cohn Coal Member
Lithostratigraphy: McLeansboro Group >>Mattoon Formation >>Cohn Coal Member
Chronostratigraphy: Paleozoic Erathem >>Pennsylvanian Subsystem >>Missourian Series
Allostratigraphy: Absaroka Sequence
Authors
M. E. Hopkins and J. A. Simon
Name Origin
The Cohn Coal Member of the Mattoon Formation (Newton and Weller, 1937, p. 18) is named for Cohn (now called Livingston), Clark County.
Type Section
The type section consists of an exposure on the south side of Big Creek, about 2.5 miles from Livingston (NE 1, 11N-12W).
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.
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.
Stratigraphic Position
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.
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 |
|---|---|