Activation history of the Hutchinson dunes in east-central Kansas, USA during the past 2200 years

This paper presents data for the Hutchinson dunes, the third and southernmost of three dunefields that collectively span a 400 km north-south transect of the eastern Great Plains. Optically stimulated luminescence dating was used to create a new, high temporal- and spatial-resolution chronology of dunefield activity, which spans the last 2200 years. Ages indicate that three major episodes of dune activity occurred similar to 2100-1800, similar to 1000-900, and after similar to 600 years ago, especially within the past 420-70 years. Dune activity similar to 1000-900 years ago correlates to the height of the Medieval Climatic Anomaly. Widespread dune activity during the past 600 years, which peaked similar to 320 and similar to 200 years ago, correlates with the coolest periods of the Little Ice Age. Dune activity in the Hutchinson dunes during the Medieval Climatic Anomaly correlates well with available proxy data and dune records from the region, including other eastern-margin dunefields, and suggests that one or more severe droughts were occurring throughout most of the Great Plains at this time. Dune activity during the Little Ice Age, unlike that of the Medieval Climatic Anomaly, does not correlate with other eastern margin dunefields, but does with those in western Kansas, Colorado, Oklahoma, and Texas and with other regional proxies. This pattern suggests that Little Ice Age droughts, unlike those associated with the Medieval Climatic Anomaly, were less intense and/orgeographically limited. Little Ice Age droughts, though, were still significant as evidenced by the migration of large dune forms in the Hutchinson dunes at this time. (c) 2012 Elsevier B.V. All rights reserved.