Lombard Dolomite Member
Lithostratigraphy: Knox Dolomite Megagroup >>Eau Claire Formation >>Lombard Dolomite Member
Chronostratigraphy: Paleozoic Erathem >>Cambrian System >>Croixan Series >>Dresbachian 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)
T. C. Buschbach
Name
Original description
The Lombard Dolomite Member of the Eau Claire Formation (Buschbach, 1964, p. 32).
Derivation
Named for Lombard, Du Page County.
Other names
History/background
Type section
Type location
The type section of the Lombard Dolomite Member is located 2 miles east of Lombard, DuPage County, and is at a depth of 1535-1640 feet (sample set 15,336) in the same boring as the Elmhurst Member.
Type author(s)
Type status
Reference section
Reference location
Reference author(s)
Reference status
Stratigraphic relationships
The Lombard Dolomite Member overlies the Elmhurst Member of the Eau Claire Formation.
Extent and thickness
The Lombard Member is recognized in northeastern Illinois, where it ranges from a few to 150 feet thick.
Lithology
The Lombard consists chiefly of grayish brown, glauconitic, partly sandy dolomite containing beds of greenish gray shale. It contains beds of limestone in Kane and DuPage Counties. Northward and westward it grades to sandstone, and southward it becomes more shaly.
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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