The purpose of this paper is to show the stratigraphic relations of the Greenhorn and Niobrara formations from Sioux City, Iowa, northward along the Big Sioux River, and westward along the Missouri River. It is concluded that the Niobrara formation does not occur in Iowa, but that the chalky beds described by Bain, Calvin and others belong to the Greenhorn formation.
Proceedings of the Iowa Academy of Science
©1931 Iowa Academy of Science, Inc.
Georgesen, N. C.
"The Stratigraphic Relations of the Greenhorn and Niobrara Formations of Western Iowa and Adjacent Areas,"
Proceedings of the Iowa Academy of Science, 38(1), 204-204.
Available at: https://scholarworks.uni.edu/pias/vol38/iss1/45