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Document Type

Research

Keywords

Paleosols, Quaternary, Sangamon Soil, radiocarbon, southeastern Minnesota, soil descriptions

Abstract

A recent roadcut along County Road 18 in northeastern Houston County has exposed two variants of a morphologically well-expressed, Sangamon Soil. The paleosol is covered by the equivalent of the Roxana Silt, as defined in Illinois. The Farmdale Soil is developed into the Roxana Silt. The section is capped by late Wisconsinan Peoria Loess. The Sangamon Soil was developed into slope wash deposits composed of, or derived from, pre-Wisconsinan loess. No direct evidence of pre-Wisconsinan glacial till was found at the site. Two radiocarbon ages, one from the Ab horizon of the Sangamon Soil and one from the Ab horizon of the Farmdale Soil yield results of 25,690 and 23,760 respectively. These are minimum ages that suggest that the Roxana Silt buried the older Sangamon Soil prior to 26,000 radiocarbon years ago and that the Peoria Loess buried the Farmdale Soil by 24,000 radiocarbon years ago.

Publication Date

December 1987

Journal Title

Proceedings of the Iowa Academy of Science

Volume

94

Issue

4

First Page

111

Last Page

115

Copyright

© Copyright 1987 by the Iowa Academy of Science, Inc.

Language

EN

File Format

application/pdf

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