On June 23, 1876, at the first annual meeting of the Iowa Academy of Science at Iowa City, Prof. Samuel Calvin read a paper entitled "Preliminary Notice of Some Dark Shales near Independence, Iowa." The paper was not published but early in 1877 an abstract of it appeared in the American Naturalist, Vol. 11, pp. 57-58. In this abstract the shale is referred to the Marcellus due to its position below certain limestones, then believed to be Hamilton, and due also to the presence of a shell presumably of Marcellus age. The shale had been discovered in the bottom of a more or less temporary quarry by Mr. D. S. Deering, one of Professor Calvin's students.
Proceedings of the Iowa Academy of Science
©1919 Iowa Academy of Science, Inc.
Thomas, A. O.
"The Independence Shale near Brandon, Iowa,"
Proceedings of the Iowa Academy of Science, 26(1), 485-491.
Available at: https://scholarworks.uni.edu/pias/vol26/iss1/47