The Pleasanton Group (Upper Pennsylvanian) in Kansas

Abstract

he Pleasanton Group, a span of rocks that is mostly shale but includes some sandstone, limestone, and coal, is described as it occurs in its belt of outcrop in eastern Kansas. These rocks, which for several years previous to 1948 were called the "Bourbon Group," are of early Missourian age (Upper Pennsylvanian). The Group comprises, in ascending order, the Seminole Formation, the Checkerboard Limestone, and the Tacket Formation (a new stratigraphic name introduced in this paper). Another new name, South Mound Shale Member, is introduced for the upper member of the Seminole Formation, whose lower member is the Hepler Sandstone. A thick sequence of dark limestone and shale beds, known as "Bourbon flags" and some lenticular sandstone bodies (Knobtown sandstone) are characteristic of facies of the Seminole-Tacket formations, the name applied to the entire span of Pleasanton rocks in the northern part of its outcrop area where the separating Checkerboard Limestone is not identified.