Historical:Big Creek Shale Member
M. E. Hopkins and J. A. Simon
The Big Creek Shale Member of the Carbondale Formation (Savage, 1927, p. 309, 313, 315) is named for Big Creek in Fulton County.
The type section occurs along Big Creek (7N-4E) (Wanless, 1957, p. 108).
Extent and Thickness
The Big Creek Shale Member is 10-30 feet thick. A shale is present at this position throughout much of the state, but the name has been used only in western Illinois.
The shale is gray, soft, and sandy, and grades into the underlying Vermilionville Sandstone.
SAVAGE, T. E., 1927, Significant breaks and overlaps in the Pennsylvanian rocks of Illinois: American Journal of Science, v. 14, p. 307-316.
WANLESS, H. R., 1957, Geology and mineral resources of the Beardstown, Glasford, Havana, and Vermont Quadrangles: Illinois State Geological Survey Bulletin 82, 233 p.
|Stratigraphic Code||Geo Unit Designation|