South-Central Section - 48th Annual Meeting (17–18 March 2014)

Paper No. 2
Presentation Time: 8:20 AM

A COMPARISON OF OSAGE MARKER BEDS IN SOUTHWESTERN IOWA WITH THOSE OF THE SOUTHERN OZARKS


HAINES, Forrest, Adrian College, 14900 Wellwood Rd, Brooklyn, MI 49230, fhaines@adrian.edu

Osage marker beds are a valuable correlation tool. In a comparison of Iowa and the Ozarks marker beds give a detailed correlation - to the craton margin in Arkansas where the units thin and become cherty. Most marker beds are either oolite or crinoid grainstones, up to a meter thick, deposited during warm interglacial intervals on the craton. The silty partings formed during glacial lowstands with erosion of the inner craton.