With its even plains surface, the infrequency of bed-rock exposures, and the universal presence of thick till or loess mantles, detailed geologic mapping of the prairie states is attended by many inherent difficulties not met with in more broken country. In consequence of the existence of these unusual conditions the consideration of possible noteworthy geotectonic features in the region is largely neglected. Anything beyond a few of the most obvious local characters completely fail of record. Over a very large part of the Mississippi basin the tectonics are commonly treated as if there were none at all. It seems to suffice to regard the strata as essentially flat-lying and as having no pretense to deformation of any kind. In Iowa, for instance, beyond the general assertion that the foundation rocks dip gently to the southwest no further note is made of the local or broader tectonic characters.
Proceedings of the Iowa Academy of Science
©1916 Iowa Academy of Science, Inc.
"Controlling Fault Systems in Iowa,"
Proceedings of the Iowa Academy of Science, 23(1), 103-112.
Available at: https://scholarworks.uni.edu/pias/vol23/iss1/16