Investigating the human response to the medieval climate anomaly in the Nebraska Sand Hills: A preliminary study in building occupation histories with OSL dating

Abstract

<p>Multiple periods of dune activation triggered by drought have occurred within the Nebraska Sand Hills, the most recent period occurred during the medieval climate anomaly (MCA; A.D. 900–1350). We present a pilot study where we have successfully adapted a standard chronology-building tool, optically stimulated luminescence dating, to investigate the effects of dune reactivation on human occupation history at two sites conventionally dated to the peri-MCA: Kelso (25HO23), a Plains Woodland site, and McIntosh (25BW15) a Central Plains tradition site. At both sites the maximum optical age of the cultural layer is congruent with radiocarbon ages of materials recovered. The optical ages yielded by samples collected near the Kelso and McIntosh sites, together with radiocarbon dated site materials, suggest that these sites were respectively occupied before and during the MCA sand dune migration. Both the Kelso and McIntosh sites are located near prominent water resources that may have acted as refuges during drought and dune migration.</p