Evidence of Cyclic Sedimentation in Kansas during the Permian Period

Abstract

In Kansias the Permian system comprises two series: below, the Big Blue which in turn comprises the Council Grove, Chase, and Sumner groups; and above, the Cimarron series. The upper series is commonly known as the beds. The upper formations of the Sumner group, the Wellington and the Pearl, which are at the top of the Big Blue series are composed of more than five hundred feet of shale with a great quantity of salt, a considerable amount of gypsum, and a little dolomitic limestone, and hence differ from the lower part of the series which has a rather large amount of limestone and marine shale. Locally there is some gypsum in the lower part of the series. Because of this difference between the upper and lower parts of the Big Blue series, the Kansas Permian is patently divisible into three major parts: (1) a lower division of limestone and shale which is somewhat like the n,nderlying Pennsylvanian strata but differs from them in ways which are listed below; (2) a middle division mostly of shale but with large quantities of salt and some gypsum; and (3) an upper division, the beds. The upper of these three divisions, the Cimarron series, is chiefly of red sand and finer clastic sediments with rather unimportant quantities of gypsum and dolomitic limestone. The lower of these three divisions differs from the Pennsylvanian beds below chiefly as follows: there is no coal in the Permian rocks as far as the writer knows, and although some has been reported (1) it must be very local in extent; dark carbonaceous shale does not occur many feet above the base of the Permian system as it recently has been fixed by Moore (2) at the base of the Americus limestone; sandstone is nearly or quiet absent in the lower part of the Permian; the statigraphic units are more persistent along their line of outcrop; and there is more highly colored shale in the Permian than in the Pennsylvanian strata. In several cases these differences point toward a greater prevalence of marine conditions during Permian than during Pennsylvanian time.