De Long Coal Member
Lithostratigraphy: Kewanee Group >>Spoon Formation >>De Long Coal Member
Chronostratigraphy: Paleozoic Erathem >>Pennsylvanian Subsystem >>Desmoinesian 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 De Long Coal Member of the Spoon Formation (Wanless, 1931a, p. 188-192).
Derivation
Named for De Long, Knox County.
Other names
It was called the Upper De Long Coal until "De Long," which had been applied to three coals, was restricted to the uppermost coal (Kosanke et al., 1960, p. 33).
History/background
Type section
Type location
It is the uppermost of three thin coals that crop out about 1 1/2 miles southwest of De Long along Brush Creek, the type locality (6, 8, 9N-2E) (Wanless, 1956, p. 9; 1957, p. 188-192).
Type author(s)
Type status
Reference section
Reference location
Reference author(s)
Reference status
Stratigraphic relationships
The coal is separated from the overlying Seahorne Limestone by soft, poorly laminated shale 1-15 feet thick, and from the underlying Brush Coal by 1-3.5 feet of claystone and, commonly, a few inches of soft, light gray shale immediately over the Brush Coal.
Extent and thickness
The De Long Coal is widespread in western Illinois but is not known to be more than a few inches thick.
Lithology
It is commonly made up of two thin coal seams separated by as much as 2 feet of claystone.
Core(s)
Photograph(s)
Contacts
Well log characteristics
Fossils
Age and correlation
The De Long Coal is correlated with the Mt. Rorah Coal of southern Illinois.
Environments of deposition
Economic importance
Remarks
References
KOSANKE, R. M., J. A. SIMON, H. R. WANLESS, and H. B. WILLMAN, 1960, Classification of the Pennsylvanian strata of Illinois: Illinois State Geological Survey Report of Investigations 214, 84 p.
WANLESS, H. R., 1931a, Pennsylvanian cycles in western Illinois: Illinois State Geological Survey Bulletin 60, p.
WANLESS, H. R., 1956, Classification of the Pennsylvanian rocks of Illinois as of 1956: Illinois State Geological Survey Circular 217, 14 p.
WANLESS, H. R., 1957, Geology and mineral resources of the Beardstown, Glasford, Havana, and Vermont Quadrangles: Illinois State Geological Survey Bulletin 82, 233 p.
ISGS Codes
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