First - In Warren County the drift is of uneven depth. As in other drift areas, this unevenness is not dependent entirely on the pre-glacial surface. In the unconformity of the drift on this pre-glacial surface a relation is seen indicating a similarity between the present drainage system and the pre-glacial drainage system. Second - The present river valleys and larger ravines are larger than present streams require. They fit into the pre-glacial valleys. Third - ln the smaller ravines only do we find erosion without regard to the pre-glacial configuration of the county.
Proceedings of the Iowa Academy of Sciences
©1893 Iowa Academy of Science, Inc.
Tilton, J. L.
"Origin of the Present Drainage System of Warren County,"
Proceedings of the Iowa Academy of Science, 1(Pt. 4), 31-33.
Available at: https://scholarworks.uni.edu/pias/vol1/iss4/13