The Independence shale, the earliest named formation of the Iowa Devonian, was described in 1878 by Samuel Calvin (1). He then, and later (2), stated that it was beneath the Cedar Valley limestone. Several geologists have since suggested that it was the same as the Kenwood shale (5) or a later formation (3, 7, 10) let down into the Cedar Valley. In 1935 Stainbrook (8) corroborated the conclusion of Calvin and in 1945 (9) gave all known evidences in favor of the presence of the shale beneath the Cedar Valley limestone and above the Davenport. The present paper summarizes additional evidences which have since come to light as to the stratigraphic place of the shale.
Proceedings of the Iowa Academy of Science
©1950 Iowa Academy of Science, Inc.
Stainbrook, Merrill A.
"Additional Notes on the Position of the Independence Shale of the Iowa Devonian,"
Proceedings of the Iowa Academy of Science, 57(1), 293-298.
Available at: https://scholarworks.uni.edu/pias/vol57/iss1/36