Hermon Coal Member
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.
M. E. Hopkins and J. A. Simon
The Hermon Coal Member of the Spoon Formation (Kosanke et al., 1960, p. 33).
Named for Hermon, Knox County.
The unit formerly was called the Lower De Long Coal (Wanless, 1931a, p. 188-192).
The type locality is along Brush Creek in Knox County, where the Hermon is the lowest of three thin coals (6, 8, 9N-2E) (Wanless, 1956, p. 9; 1957, p. 73-74).
Extent and thickness
The Hermon Coal is found in many parts of western Illinois but is discontinuous. At most places it is represented by 2 inches or less of carbonaceous shale or bony coal. Near Canton in Fulton County, where it occurs locally over thick Rock Island Coal and thick Seville Limestone, the coal is as much as 4 feet thick. It is generally underlain by as much as 4 feet of gray underclay.
Well log characteristics
Age and correlation
No coal equivalent to the Hermon Coal has been recognized in southern Illinois.
Environments of deposition
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.
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