The lower Chester formations are correlated in western Illinois, the subsurface of the southeastern Illinois basin, Hardin County, Illinois, and Indiana. The correlation of the western Illinois formations is based on unpublished work by Frank E. Tippie. The Paint Creek of southern and western Illinois is divided into three members: (1) an upper limestone and shale zone, named the Ridenhower member, and correlated with the "Paint Creek" of southeastern Illinois; (2) a middle sandstone and shale zone, correlated with the Bethel sandstone of southeastern Illinois; and (3) a lower "pink crinoidal limestone" correlated with the upper part of the "Renault" formation and called the Downeys Bluff member in southeastern Illinois. The remainder of the "Renault" formation in southea tern Illinois is referred to as the Shetlerville member of the Renault formation. In its upper part it includes a sandstone which is correlated with the subsurface "Benoist sand" of the western part of the Illinois basin and possibly the Yankeetown of western Illinois. Sections prepared by Tippie show that the Aux Vases formation may be confined to western Illinois.

The "Aux Vases" and "Rosiclare" of the subsurface in southeastern Illinois are correlated respectively with the Rosiclare and Spar Mountain (sub-Rosiclare) of Hardin County, Illinois.

The correlations of lower Chester formations of Illinois with those of Indiana are shown.

End_of_Article - Last_Page 300------------