Kress Member
Lithostratigraphy: Ottawa Limestone Megagroup >>Ancell Group >>St. Peter Sandstone >>Kress Member
Chronostratigraphy: Paleozoic Erathem >>Ordovician System >>Champlainian Series >>Blackriveran Stage
Allostratigraphy: Tippecanoe Sequence
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)
H. B. Willman and T. C. Buschbach
Name
Original description
The Kress Member of the St. Peter Sandstone (Buschbach, 1964, p. 51).
Derivation
Named for Kress Creek, a stream northwest of West Chicago, Du Page County, near the type section.
Other names
History/background
Type section
Type location
The type section of the Kress Member is defined near Kress Creek, near which a well (NW NE SE 32, 40N-9E) encountered 64 feet of conglomerate at the base of the St. Peter, the top at a depth of 940 feet. The type section is represented by samples from the well (sample set 1169).
Type author(s)
Type status
Reference section
Reference location
Reference author(s)
Reference status
Stratigraphic relationships
The Kress Member is the basal member of the St. Peter Sandstone (Buschbach, 1964, p. 51).
Extent and thickness
The Kress Member is very irregular in occurrence but has been encountered in many wells. Its maximum thickness is 170 feet in a well in Ogle County, where a thin layer of bentonite occurs near its base.
Lithology
The Kress in some places is a coarse rubble or conglomerate of chert in a matrix of clay or sand, a residue from the solution of the underlying cherty dolomites and sandstones. At other places the Kress is largely red sandy clay, red and green shale, and argillaceous sandstone that represent reworking of the residual materials by the advancing St. Peter sea. The conglomerate is locally exposed in the Oregon region, Ogle County, and the shale is exposed at Utica, La Salle County.
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.
ISGS Codes
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