Recent grading of a road in Jackson county, Iowa, led to the uncovering and subsequent discovery of an outlier of Devonian limestone. This outlier was first noted while the author was searching for a suitable quarry site in Jackson County, southeast of Maquoketa. The area is located south of center section 33 Maquoketa Township, just about one-fourth mile north of the Clinton-Jackson county line. With the exception of an area along the Mississippi River and a smaller area around the town of Preston, where Ordovician rocks are exposed, Jackson County is underlain by Silurian dolomites of the Niagara Series. Other than the Devonian outlier found by Norton near Canton, the nearest known Devonian is approximately thirty-five to forty miles south and south-west.
Proceedings of the Iowa Academy of Science
©1953 Iowa Academy of Science, Inc.
Dorheim, Fred H.
"Devonian Outlier in Jackson County, Iowa,"
Proceedings of the Iowa Academy of Science, 60(1), 362-365.
Available at: https://scholarworks.uni.edu/pias/vol60/iss1/45