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.
H. B. Willman and John C. Frye
The Gulfian Series (Hill, 1887, p. 298, 300).
Named for its occurrence along the Coastal Plain of the Gulf of Mexico, and is presumed to include all Cretaceous rocks in Illinois.
Extent and thickness
Well log characteristics
Age and correlation
In southern Illinois most of the Cretaceous rocks were deposited during the youngest part of the Gulfian, although the basal Tuscaloosa Formation may represent early deposits of the series. Cretaceous rocks in western Illinois were probably deposited during early Gulfian time.
Environments of deposition
HILL, R. T., 1887, Topography and geology of the Cross Timbers and surrounding regions in northern Texas: American Journal of Science, v. 33, p. 291-303.
|Stratigraphic Code||Geo Unit Designation|