O'Nan 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 O'Nan Coal Member of the Spoon Formation (Kosanke et al., 1960, p. 32).
Named for Dennis O'Nan Ditch, which flows across the tip of Indian Hill, Union County, Kentucky, the type locality (Glenn, 1912, p. 25).
It previously was called the Curlew Coal (Owen, 1856, p. 47).
Extent and thickness
The O'Nan Coal is generally thin, seldom over 1 foot thick in its scattered occurrences in southern Illinois.
Well log characteristics
Age and correlation
It is now believed to be equivalent to the Bidwell Coal.
Environments of deposition
GLENN, L. C., 1912, A geological reconnaissance of the Tradewater River region, with special reference to the coal beds: Kentucky Geological Survey Bulletin 17, 75 p.
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.
OWEN, D. D., 1856, Report of the geological survey in Kentucky made during the years 1854 and 1855: Kentucky Geological Survey Bulletin, v. I, Series 1, 416 p.
|Stratigraphic Code||Geo Unit Designation|