The lithology of certain Benton (?) strata in Lyon County and adjacent parts of Minnehaha County, South Dakota is described. These rocks differ greatly from the common type of limestone and chalk of the Cretaceous of the Big Sioux and Missouri River region. The formation contains large quantities of siliceous material in the matrix and as spicules and in some beds as chert. Fragments of glass are common in one zone.
Proceedings of the Iowa Academy of Science
©1930 Iowa Academy of Science, Inc.
Tester, A. C.
"A Note on the Stratigraphy of the Cretaceous in Northwestern Iowa,"
Proceedings of the Iowa Academy of Science, 37(1), 275-275.
Available at: https://scholarworks.uni.edu/pias/vol37/iss1/63