Blodgett Member
Lithostratigraphy: Knox Dolomite Megagroup >>Prairie du Chien Group >>Oneota Dolomite >>Blodgett Member
Chronostratigraphy: Paleozoic Erathem >>Ordovician System >>Canadian Series >>Trempealeauan Stage
Allostratigraphy: Sauk 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 Blodgett Member of the Oneota Dolomite (Buschbach, 1964, p. 45).
Derivation
The Blodgett Member is named for the town of Blodgett, western Will County.
Other names
History/background
Type section
Type location
The type section of the Blodgett Member is located 3 miles northeast of Blodgett, western Will County, in a boring (NE NE SW 25, 34N-9E) and is represented by samples (sample set 6199) from 885-980 feet deep.
Type author(s)
Type status
Reference section
Reference location
Reference author(s)
Reference status
Stratigraphic relationships
The Blodgett Member of the Oneota Dolomite is the upper, noncherty, or only slightly cherty, member.
Extent and thickness
The Blodgett is recognized in the northeastern quarter of the state, where it ranges from 90 to over 100 feet thick.
Lithology
It is dolomite, sandy in part, very slightly glauconitic, light or pinkish gray, and medium to fine grained. Oolitic chert is present but not abundant. Thin green shale partings are widely spaced throughout the member.
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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