The Correlation of Rocks of Simpson Age in North-Central Kansas with the St. Peter Sandstone and Associates Rocks in Northwestern Missouri

Abstract

The lower part of the Simpson rocks in the Salina basin, here designated the St. Peter sandstone, consists of two sandstones separated by shaly beds. These sandstones are characterized by rounded grains and, except for the shaly parting between them, they are lithologically similar to the St. Peter sandstone of northwestern Missouri with which this part of the Simpson is correlated. The upper part of the Simpson rocks in the Salina basin, here designated the Platteville formation, consists of beds of shale, sandstone, dolomite, and limestone. It is somewhat variable in lithology because of lateral gradation, minor disconformities, or both; however, it is collectively similar to and is the correlative of rocks in northwestern Missouri called Decorah formation by Missouri geologists and probably includes also beds equivalent to the upper part of the Plattin limestone of Missouri. The Platteville formation is also the correlative of the Platteville limestone of the upper Mississippi valley.