The presence of a considerable amount of chert in the Burlington and Keokuk limestone members of the Osage series has been the cause of frequent comment, but no critical study of the material has ever been made. The chert attains its maximum development in the upper division of the Burlington limestone known as the Montrose chert. But nodules and inconstant seams of the same material appear, also, in the lower levels of the Burlington and frequently characterize the Keokuk limestone. In the latter formation, however, the chert is found at no definite level and is entirely wanting at some localities. The present investigation was confined mainly to a study of the Montrose chert, although some attention was given to the chert from other horizons.
Proceedings of the Iowa Academy of Science
©1912 Iowa Academy of Science, Inc.
Van Tuyl, Francis M.
"A Study of the Cherst of the Osage Series of the Mississippian System,"
Proceedings of the Iowa Academy of Science, 19(1), 173-174.
Available at: https://scholarworks.uni.edu/pias/vol19/iss1/30