On a lawn at No. 629 West Maple Avenue, in Centerville, Iowa, are located two large quartzose conglomerate boulders which are of more than usual interest. These were removed from the glacial till during the process of excavating for the cellar under the dwelling now situated on the same lot and when found were said to be buried beneath several feet of drift material.
Proceedings of the Iowa Academy of Science
©1922 Iowa Academy of Science, Inc.
Wilson, Ben H.
"Deductions from the Occurrence and Character of Two Large Quartzose Conglomerate Boulders of Unknown Origin Found in the Kansan Drift Sheet at Centerville, Iowa,"
Proceedings of the Iowa Academy of Science, 29(1), 121-126.
Available at: https://scholarworks.uni.edu/pias/vol29/iss1/19