Dresbachian Stage
Chronostratigraphy: Paleozoic Erathem >>Cambrian System >>Croixan Series >>Dresbachian Stage
Primary source
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.
Contributing author(s)
T. C. Buschbach
Name
Original description
Dresbachian Stage (Winchell, 1886, p. 334-337).
Derivation
Named for Dresbach, Winona County, Minnesota.
Other names
History/background
These strata were originally called the Dresbach Sandstone (or Formation) and in some areas are now referred to as the Dresbach Group.
Type section
Type location
Type author(s)
Type status
Reference section
Reference location
Reference author(s)
Reference status
Stratigraphic relationships
The Dresbachian Stage consists of all strata of Croixan age below the Elvinia Zone. It includes the Cedaria (oldest), Crepicephalus, and Aphelaspis Zones (Howell et al., 1944). As the Mt. Simon and Galesville Sandstones lack fossils, the precise boundaries of the stage are uncertain (Buschbach, 1964).
Extent and thickness
In Illinois the stage is represented by 1500-3500 feet of sandstone and dolomite that is differentiated into the Mt. Simon Sandstone (below), the Eau Claire Formation, and the Galesville Sandstone.
Lithology
Core(s)
Photograph(s)
Contacts
Well log characteristics
Fossils
Age and correlation
Environments of deposition
Economic importance
Remarks
References
BUSCHBACH, T. C., 1964, Cambrian and Ordovician strata of northeastern Illinois: Illinois State Geological Survey Report of Investigations 218, 90 p.
HOWELL, B. F., et al., 1944, Correlation of the Cambrian formations of North America: Geological Society of America Bulletin, v. 55, p. 993-1003.
WINCHELL, N. H., 1886, Revision of the stratigraphy of the Cambrian in Minnesota: Minnesota Geological and Natural History Survey 14th Annual Report (1885), p. 325-337.
ISGS Codes
Stratigraphic Code | Geo Unit Designation |
---|---|