Big Clifty Sandstone Member
Lithostratigraphy: Pope Megagroup >>Okaw Group >>Golconda Group >>Fraileys Shale >>Big Clifty Sandstone Member
Chronostratigraphy: Paleozoic Erathem >>Mississippian Subsystem >>Chesterian Series >>Hombergian Stage
Allostratigraphy: Kaskaskia Sequence
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.
Elwood Atherton, Charles Collinson, and Jerry A. Lineback
Big Clifty Sandstone Member of the Fraileys Shale (Norwood, 1876, p. 405).
Named for Big Clifty Creek, Grayson County, Kentucky.
The type section of the Big Clifty Sandstone Member is along the Big Clifty Creek, 2 miles southwest of the village of Big Clifty.
It is near the middle of the Fraileys or, less commonly, near the base. In Indiana the Big Clifty occupies nearly the whole of the interval represented by the Fraileys Shale in Illinois.
Extent and thickness
The Big Clifty enters Illinois from the east and wedges out within a few tens of miles. Many wells in Lawrence, northern and eastern Jasper, and southern Cumberland Counties encounter 15-20 feet of Big Clifty. A few sporadic occurrences have been found in Marion County and east of there.
Well log characteristics
Age and correlation
Environments of deposition
“Big Clifty” and “Jackson” are informal names applied to producing zones in the Big Clifty Sandstone Member of the Fraileys Shale.
NORWOOD, C. J., 1876, Report on the geology of the region adjacent to the Louisville, Paducah, and Southwestern Railroad, with a section: Kentcuky Geological Survey, v. 1, p. 355-488.
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