Some Issues in Chester Stratigraphy in Kentucky and Illinois

Abstract

This paper is a contribution toward the settlement of a long-standing controversy concerning certain points in Chester stratigraphy in Kentucky and Illinois. The late Professor Weller correlated the Renault formation of Randolph County, Illinois, with both the upper part of the Ohara limestone and the lower part of the Gasper limestone, and also correlated the Bethel sandstone of western Kentucky with the Sample sandstone of Breckinridge County, Kentucky. He and his son, Dr. Marvin Weller, denied the validity of the name Gasper and used, instead, the hyphenated designation Renault-Paint-Creek. Professor Weller also questioned the suitability of the name Bethel for the sandstone unit so named. The present paper presents concrete evidence tending to disprove the views of the Wellers on the points mentioned. Certain characteristic species of fossils mark the lower part of the Gasper beneath the Sample sandstone and the same assemblage occurs in Christian and Caldwell counties, Kentucky, in the lower part of the typical "Tribune" limestone of Ulrich (for which the name Gasper was substituted), and above the Bethel sandstone and hence above the Ohara limestone which immediately underlies the Bethel sandstone in western Kentucky. Not one of the characteristic members of this fauna has ever been found in the Ohara limestone or below the horizon of the Bethel sandstone. From this it follows that the Bethel and Sample sandstones are not the same. Therefore the Renault formation cannot be the equivalent of both the Ohara, which is below the Bethel, and the "lower Gasper," which is above the Bethel. As it is admitted by the Wellers that the Gasper is an indivisible unit equivalent to the Renault and Paint Creek, and as the name is applied in accordance with the customary modern practice of giving a new name to two or more combined units, its validity cannot be fairly questioned. In regard to the name Bethel, it is shown that the sandstone near Bethel school, now Crittenden Springs school, which Weller thought to be the lower part of the Cypress sandstone, is directly underlain by the Ohara limestone and therefore clearly Bethel, so that the name is entirely appropriate.