INVESTIGATING THE GEOLOGIC RECORD OF PALEO-STORMS FROM LAKE AND WETLAND SEDIMENTS OF THE GREAT PLAINS

The purpose of this study was to identify the geologic signature of paleo-storm events within the mid-continent region. This research also aimed to create a better understanding of the long-term geologic history of major storms and to allow for better-informed projections regarding future return periods for such storms. The study locations were Cheyenne Bottoms Wildlife Refuge, Kansas and Canton Lake, Oklahoma. To determine the geologic signature of major storms, sediment cores were taken at both locations and sampled at 3 mm intervals for grain size analysis using a Cilas laser particle size analyzer. Chronology was determined through Pb-210, Cs-137 and C-14 dating methods. Using a recent known major storm occurrence at Canton Lake, the signature created by storms in the geologic record was identified. The resulting signature was then used to identify paleo-storms in the longer-term record in the Cheyenne Bottoms core. The results were also used to determine storm/climate cycles in the long-term geologic record, and calculate true return periods for major storms. A better understanding of true return periods and possible increases in frequency or intensity of large storms is essential in the effort to mitigate future damage to infrastructure and loss of human life.