Detailed field study, including the collection of samples, was made of the Wapsipinicon formation and adjacent Silurian and Devonian beds in Iowa. The Wapsipinicon consists of about 100 feet of limestones, dolomites, and calcareous shales that are divided from the base upward into the Coggan, Otis, Kenwood, Spring Grove, and Davenport members. In the laboratory, the samples were digested in acid to determine the amount of insoluble residue, the mineralogy of the residue was studied with the aid of a petrographic microscope, and the ratio of calcite to dolomite in the samples was determined by means of stains. All three criteria (percentage of insoluble residue, mineralogy of insoluble residue, and calcite-dolomite ratio) were found to be of aid in correlation, but they are rarely conclusive evidence except when used together and in conjunction with field evidence.

First Page Preview

First page PDF preview
You do not currently have access to this article.