Creal Springs Limestone 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 Creal Springs Limestone Member of the Spoon Formation (Kosanke et al., 1960, p. 32, 64, 65).
Named for Creal Springs, Williamson County.
The type section consists of exposures in the sandstone quarry east of Creal Springs (NE SE SE 25, 10S-3E).
In the type area the Creal Springs lies on the Granger Sandstone, but throughout much of its extent it is separated from the underlying Murphysboro Coal by several feet of gray shale.
Extent and thickness
The Creal Springs is lenticular and occurs sporadically in a large part of southern Illinois.
The Creal Springs Limestone is gray, argillaceous, and in places cherty. It is seldom over 2 feet thick and contains an open-marine fauna.
Well log characteristics
Age and correlation
In some places it was once correlated with the Curlew Limestone, but the fusulinids it contains indicate it is younger than the Curlew (Thompson et al., 1959).
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.
THOMPSON, M. L., R. H. SHAVER, and E. A. RIGGS, 1959, Early Pennsylvanian fusulinids and ostracodes of the Illinois Basin: Journal of Paleontology, v. 33, p. 770-792; Illinois State Geological Survey Reprint 1959-P.
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