The early geologists who surveyed the state reported many small, scattered patches of Pennsylvanian sandstone north and east of the principal Pennsylvanian area in Iowa, The outliers along the Iowa River north and east of Iowa City were among the first to be described. Subsequently more complete descriptions of these and other outliers in Johnson and adjacent counties have appeared in the publications of the Iowa Geological Survey and in other scientific journals. References to these articles can be found in Ia. Geol. Survey Rept. Vol. 22, 1912.
Proceedings of the Iowa Academy of Science
©1926 Iowa Academy of Science, Inc.
Adams, John E.
"Butler's Landing Outlier and Its Fossil Flora,"
Proceedings of the Iowa Academy of Science, 33(1), 177-178.
Available at: https://scholarworks.uni.edu/pias/vol33/iss1/35