In 1931 the Fort Dodge Limestone Company was organized for the purpose of obtaining rock from a mine located in the S. W.Y4, Sec. 24, T. 89N., R. 29W., Webster County, Iowa. Mining of this rock has been essentially continuous since that time. The rocks penetrated by the mine shaft and the working face have been described by Wood (1933). The petrography of the rocks of the working face has been described by Weissmann (1953), and by Roy, Thomas, Weissmann, and Schneider (1955) . Although all workers have agreed that the rocks of the mine arc of Mississippian age, no agreement has been reached as to the precise stratigraphic placement of this sequence within this system. The rock of the working face is known to be a lenticular body with a maximum thickness of about 18 feet. Lateral contacts are controlled along the south side by a graben-type fault with a minimum displacement of about 120 feet. This displacement brings Pennsylvanian shales in contact with the Mississippian rocks. In the other directions the mine rock thins out to thicknesses of six feet or less so that commercial exploitation is no longer feasible.
Proceedings of the Iowa Academy of Science
© Copyright 1956 by the Iowa Academy of Science, Inc.
Thomas, Leo A. and Williams, Wayne W.
"The Gilmore City Formation at Fort Dodge, Iowa,"
Proceedings of the Iowa Academy of Science, 63(1), 445-449.
Available at: https://scholarworks.uni.edu/pias/vol63/iss1/46