Abstract

Two pollen analyses from Quaternary deposits located outside both the Illinoian and Wisconsinan limits of glaciation in east-central Iowa, U.S.A., are similar to other analyses in the Midwest. One analysis from sediments between two pre-Illinoian tills is high in coniferous pollen. The analysis suggests a cool late interglacial or an interstadial climate. The other analysis is from Late Wisconsinan sediments synchronous with the last increment of loess deposition. The pollen diagram may be divided into three major zones: zone 1 may represent a boreal parkland, zone 2 contains the spruce maximum about 14 000 radiocarbon years before present, and zone 3 shows an increase in pine and oak pollen about 11 000 years ago.

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