Elwood Atherton, Charles Collinson, and Jerry A. Lineback
The Renault Limestone (S. Weller, 1913, p. 120, 122; Swann, 1963, p. 79), the lower part of which is Valmeyeran in age and the upper part Chesterian, is 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).
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.
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.
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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