Mississippian System

Type locality, characteristic section, and use of name in Illinois: The Renault Limestone was named by Stuart Weller (1913, p. 120, 122) for exposures in Renault Township, Monroe County, Ill., but he designated no type section. Swann (1963, p. 79) noted a representative section on the south side of Dry Fork in the type area (SE¼SW¼ sec. 23, T. 4 S., R. 9 W.). As presently defined in Illinois, the Renault Limestone is commonly about 8 feet (2.4 m) thick (Willman and others, 1975, p. 144) and consists of two members, a lower, relatively pure limestone (Levias Limestone Member) and an upper sandy limestone (Shetlerville Limestone Member).

Description and correlation: In Indiana the Renault Formation is recognized only in the subsurface. Because it apparently spans a greater stratigraphic range and certainly includes a greater variety of lithologic types than it does in Illinois usage, it has long been designated with the surname formation. It overlies the Aux Vases Formation (Valmeyeran) conformably, and in most places it is overlain conformably by the Bethel Formation (Chesterian). In a belt extending from Lawrence County to Vanderburgh County, however, it is overlain disconformably and in places is entirely cut out by clastic rocks associated with the West Baden clastic belt (see under "Elwren Formation"), and it is terminated northward where it is disconformably overlapped by rocks of Pennsylvanian age in Putnam, Parke, and Vermillion Counties. The Renault Formation ranges from a few to more than 90 feet (27 m) in thickness and is widely recognized in the petroleum-producing part of southwestern Indiana.

According to Pinsak (1957) and Swann (1963), the Renault Formation of Indiana subsurface usage includes equivalents of the entire Paoli Limestone and the upper part of the Levias Member of the Ste. Genevieve Limestone of Indiana outcrop usage. In Illinois equivalents it embraces not only the Renault but also the Yankeetown Sandstone and the Downeys Bluff Limestone (fig. 2). The formation is highly variable, but in many places it can be divided into three parts. The upper part, light-tan to tan fine- to medium-grained limestone, is equivalent to the Downeys Bluff Limestone of Swann (1963). The middle part, a green calcareous shale that in places contains quartz sand and lenses of limestone, is probably equivalent to the Yankeetown Sandstone of Swann (1963). The lower part is tan to gray-tan medium-grained limestone and light-tan crystalline to oolitic limestone. These may be equivalent to the Shetlerville and Levias Limestone Members of the Renault Limestone of Swann (1963).