Willis 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 Willis Coal Member of the Abbott Formation (Butts, 1925, p. 62-63).
Named for the Willis Mine in Gallatin County (SE SW 30, 10S-9E).
In the type area the Willis is closely underlain by the Grindstaff Sandstone Member and is immediately overlain by about 40 feet of Finnie Sandstone.
Extent and thickness
The coal is present at widely scattered localities in the outcrop area in southern Illinois. It has been mined locally in southeastern Illinois, where it is 3-3.5 feet thick.
Well log characteristics
Age and correlation
It is correlated with the Tarter Coal of western Illinois and the Lower Block Coal Member of Indiana.
Environments of deposition
BUTTS, CHARLES, 1925, Geology and mineral resources of the Equality-Shawneetown area: Illinois State Geological Survey Bulletin 47, 76 p.
|Geo Unit Designation