Midwestern Holocene paleoenvironments revealed by floodplain deposits in northeastern Iowa
Pollen analysis of pond deposits in the upper reaches of a stream from northeastern Iowa, an area beyond the last glacial margin, provides a nearly complete record of vegetational changes during the last 12.5 thousand years. Sixty-one radiocarbon dates provide good chronological control. Spruce forest was replaced by deciduous forest before 9 1 thousand years ago, followed by prairie from 5.4 to 3.5 thousand years ago, and oak savanna from 3.5 thousand years ago until presettlement times. The prairie invasion was nearly 3 thousand years later here than at other sites in Iowa and Minnesota, documenting a late Holocene, rather than an early-middle Holocene, period of maximum warmth and dryness for the southern part of the upper Midwest.
Citation Information
Publication Year | 1990 |
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Title | Midwestern Holocene paleoenvironments revealed by floodplain deposits in northeastern Iowa |
Authors | C. A. Chumbley, R. G. Baker, E. Arthur Bettis |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Science |
Index ID | 70016176 |
Record Source | USGS Publications Warehouse |