Bonpas Limestone Member
Lithostratigraphy: McLeansboro Group >>Mattoon Formation >>Bonpas Limestone Member
Chronostratigraphy: Paleozoic Erathem >>Pennsylvanian Subsystem >>Missourian Series
Allostratigraphy: Absaroka 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)
M. E. Hopkins and J. A. Simon
Name
Original description
The Bonpas Limestone Member of the Mattoon Formation (Kosanke et al., 1960, p. 41).
Derivation
Named for Bonpas Creek, Richland County.
Other names
It previously was called Calhoun Limestone (Weller, in Dunbar and Henbest, 1942, p. 27).
History/background
Type section
Type location
The type section is in a roadcut exposure about 1.5 miles west of Bonpas Creek, the same location as the Calhoun Coal type section (Kosanke et al., 1960, p. 41, 82).
Type author(s)
Type status
Reference section
Reference location
Reference author(s)
Reference status
Stratigraphic relationships
Extent and thickness
The Bonpas is 3 feet thick in the type locality and is widely distributed in eastern Illinois.
Lithology
Core(s)
Photograph(s)
Contacts
Well log characteristics
Fossils
The Bonpas contains a varied open-marine fauna.
Age and correlation
It is correlated with the Omega Limestone of the western side of the area covered by the Mattoon Formation.
Environments of deposition
Economic importance
Remarks
References
DUNBAR, C. O., and L. G. HENBEST, 1942, Pennsylvanian Fusulinidae of Illinois: Illinois State Geological Survey Bulletin 67, 218 p.
KOSANKE, R. M., J. A. SIMON, H. R. WANLESS, and H. B. WILLMAN, 1960, Classification of the Pennsylvanian strata of Illinois: Illinois State Geological Survey Report of Investigations 214, 84 p.
ISGS Codes
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