Title

Speleothem evidence for Holocene fluctuations of the prairie-forest ecotone, north-central USA

Document Type

Article

Peer Reviewed

1

Publication Date

9-1-1999

Journal/Book/Conference Title

Holocene

Volume

9

DOI

10.1191/095968399674716399

Abstract

Carbon and oxygen isotopic trends from seven Midwestern speleothems record significant offsets in the timing of middle-Holocene vegetation change. Interactions of dry Pacific and moist Gulf of Mexico air masses maintained a sharp moisture gradient across Iowa, Minnesota, and Wisconsin such that the arrival of prairie was offset by 2000 years between caves and pollen sites located only 50 km apart. Oxygen isotopes shift concomitantly with carbon in most cases, although these changes are believed to represent increased evaporative enrichment of super(18)O prior to infiltration during the prairie period.

Keywords

Sustainability, Carbon and oxygen isotopic trends from seven Midwestern speleothems record significant offsets in the timing of middle-Holocene vegetation change. Interactions of dry Pacific and moist Gulf of Mexico air masses maintained a sharp moisture gradient across Iowa, Minnesota, and Wisconsin such that the arrival of prairie was offset by 2000 years between caves and pollen sites located only 50 km apart. Oxygen isotopes shift concomitantly with carbon in most cases, although these changes are believed to represent increased evaporative enrichment of super(18)O prior to infiltration during the prairie period.

Published Article/Book Citation

Holocene, 9:6 (1999) pp.671-676.



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URL

http://ir.uiowa.edu/geog_pubs/213