Little Vermilion Limestone Member
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.
M. E. Hopkins and J. A. Simon
The Little Vermilion Limestone Member of the Bond Formation (Willman, in Cooper, 1945. p. 14).
Named for the Little Vermilion River in La Salle County.
The type section is exposed along Little Vermilion River (SW SW 11, 33N-1E) (Wanless, 1956, p. 12).
The Little Vermilion Limestone lies about 25 feet above the La Salle Limestone.
Extent and thickness
The Little Vermilion Limestone is as much as 4 feet thick locally.
The limestone is dark gray, argillaceous, and shaly. In the type area a coal, generally less than 1 foot thick, is found about a foot below the limestone.
Well log characteristics
It is very fossiliferous, with brachiopods (particularly Rhipidomella), bryozoans, and crinoids abundant.
Age and correlation
The Little Vermilion is tentatively correlated with the Sorento Limestone.
Environments of deposition
COOPER, C. L., 1946, Pennsylvanian ostracodes of Illinois: Illinois State Geological Survey Bulletin 70, 177 p.
WANLESS, H. R., 1956, Classification of the Pennsylvanian rocks of Illinois as of 1956: Illinois State Geological Survey Circular 217, 14 p.
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