Megadroughts and late Holocene dune activation at the eastern margin of the Great Plains, north-central Kansas, USA

TitleMegadroughts and late Holocene dune activation at the eastern margin of the Great Plains, north-central Kansas, USA
Publication TypeJournal Article
Year of Publication2010
AuthorsHanson, PR, Arbogast, AF, Johnson, WC, Joeckel, RM, Young, AR
JournalAeolian Research
Volume1
Issue3-4
Pagination101-110
Date PublishedJan
ISSN1875-9637
Accession NumberWOS:000297240600002
Abstract

Optical and radiocarbon dating indicates that alluvium underlying dunes near Abilene was deposited at or before similar to 45 ka, and that the overlying dunes were active at similar to 1.1-0.5 ka. Geochemical data indicate that the Abilene dune sand is immature and was derived from the underlying Pleistocene alluvium, and not from Holocene age Smoky Hill River deposits. These findings suggest that dune activation was a response to increased aridity and local reduction in vegetation cover as opposed to changes in sediment availability from nearby rivers. The time interval of dune activation at Abilene overlaps Medieval Warm Period megadroughts, similar to the larger and more westerly dune fields on the Great Plains, including the Nebraska Sand Hills and the Great Bend Sand Prairie. The activation of smaller dune fields such as the Abilene dunes near the more humid eastern margin of the Great Plains shows the geographic extent and severity of paleodrought events. Unlike the Duncan dunes, another plains-marginal dune field, however, the Abilene dunes show no evidence for multiple drought events during the Holocene. This difference in dune activity, if it is not a result of sampling or preservation bias, indicates variations in the extent and severity of older drought events at the eastern margin of the Great Plains. Published by Elsevier B.V.

DOI10.1016/j.aeolia.2009.10.002