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Geochemical variations in Peoria Loess of western Iowa indicate paleowinds of midcontinental North America during last glaciation

Quaternary Research

By:
and
DOI: 10.1006/qres.1999.2090

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Abstract

Peoria Loess deposited in western Iowa during the last glacial maximum (LGM) shows distinct geochemical and particle-size variations as a function of both depth and distance east of the Missouri River. Geochemical and particle-size data indicate that Peoria Loess in western Iowa probably had two sources: the Missouri River valley, and a source that lay to the west of the Missouri River. Both sources indicate that LGM paleowinds in western Iowa had a strong westerly component, similar to interpretations of previous workers. A compilation of loess studies in Iowa and elsewhere indicates that westerly winds were dominant during loess transport over much of the midcontinent south of the Laurentide ice sheet, which is not in agreement with paleowinds simulated by atmospheric general circulation models (AGCMs). AGCMs consistently generate a glacial anticyclone with easterly or northeasterly winds over the Laurentide ice sheet and the area to the south of it. Loess deposition in the midcontinent during the LGM may be a function of infrequent northwesterly winds that were unrelated to the presence of the glacial anticyclone.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Geochemical variations in Peoria Loess of western Iowa indicate paleowinds of midcontinental North America during last glaciation
Series title:
Quaternary Research
DOI:
10.1006/qres.1999.2090
Volume
53
Issue:
1
Year Published:
2000
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Quaternary Research
First page:
49
Last page:
61
Number of Pages:
13