Dresbachian Stage

From ILSTRAT
Jump to: navigation, search

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
8740
--