Romeo Member
Lithostratigraphy: Hunton Limestone Megagroup >>Joliet Formation >>Romeo Member
Chronostratigraphy: Paleozoic Erathem >>Silurian System >>Niagaran Series
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 Elwood Atherton
Name
Original description
The Romeo Member of the Joliet Formation (Willman, 1973, p. 22).
Derivation
Named for Romeo, Will County, where part of the member is exposed at the top of quarries now largely filled with water.
Other names
History/background
Type section
Type location
The type section of the Romeo Member is in the National Stone Company quarry, 6 miles south of Romeo, on the southwest side of Joliet, where it is part of the type section for the Joliet Formation, and is 20.2 feet thick.
Type author(s)
Type status
Reference section
Reference location
Reference author(s)
Reference status
Stratigraphic relationships
The Romeo Member is the top member of the Joliet Formation.
Extent and thickness
The Romeo Formation ranges from 18 feet in Rock Creek Canyon along the Kankakee River to 34 feet thick in a quarry at Elmhurst in Du Page County.
Lithology
The member consists of light gray to white, gray-weathering, pure, vesicular, thin- to medium-bedded dolomite, commonly with tight stylolitic bedding surfaces. It locally has pink mottling. It contains silicified fossils and several bands of chert nodules in the type locality, but in many exposures it exhibits little or no chert.
Core(s)
Photograph(s)
Contacts
Well log characteristics
Fossils
Corals are common and locally abundant in the Romeo Member.
Age and correlation
Environments of deposition
Economic importance
Remarks
References
WILLMAN, H. B., 1973, Rock stratigraphy of the Silurian System in northeastern and northwestern Illinois: Illinois State Geological Survey Circular 479, 55 p.
ISGS Codes
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