Difference between revisions of "Renault Limestone"
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Latest revision as of 21:28, 21 October 2019
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.
Elwood Atherton, Charles Collinson, and Jerry A. Lineback
Renault Limestone (S. Weller, 1913, p. 120, 122; Swann, 1963, p. 79).
Named for Renault Township, Monroe County.
The type section of the Renault Limestone consists of exposures in the valley of Horse Creek. A typical exposure 4 miles northeast of the village of Renault on the south side of Dry Fork (SE SW 23, 4S-9W) is accepted as the type section (Swann, 1963).
Extent and thickness
The Renault is a widespread, relatively thin formation, averaging only about 8 feet thick (fig. M-24), but it ordinarily stands out as a high-resistive unit on electric logs. The Renault thickens to more than 40 feet in part of Johnson County.
The Renault consists of a lower relatively pure limestone, the Levias Member (Valmeyeran), and an upper sandy limestone, the Shetlerville Limestone Member (Chesterian), which in turn includes a persistent sandstone bed (Popcorn Sandstone Bed) at its base. The interbedded sandstone and shale unit overlying the limestone portion in the type area was originally regarded as the upper part of the Renault but now is assigned to the Yankeetown.
Well log characteristics
Age and correlation
The lower part of the Renault Limestone is Valmeyeran in age and the upper part Chesterian.
In some earlier reports the Levias Member was miscorrelated with strata below the Aux Vases Sandstone and it was therefore classified as a member of the Ste. Genevieve Formation.
Environments of deposition
“Lower Renault" or "Renault sand” are informal names applied to producing zones in the Renault Limestone.
SWANN, D. H., 1963, Classification of Genevievian and Chesterian (Late Mississippian) rocks of Illinois: Illinois State Geological Survey Report of Investigations 216, 91 p.
WELLER, STUART, 1913, Stratigraphy of the Chester Group in southwestern Illinois: Illinois Academy of Science Transactions, v. 6, p. 118-129.
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