DEVELOPMENT OF A PROXY FOR MAJOR STORMS IN THE MIDCONTINENT

Particle size distribution (PSD) of detrital sediments has traditionally been used as a reliable indicator of depositional environments. PSD has also been employed to demonstrate the frequency of storm activity when a long-term record is preserved in sediment deposits. In analysis of late Quaternary paleostorm activity in the mid-continent, characterization of PSD is an essential tool. However, analyses and comparisons of different sizes and other characteristics of sediment particles can be challenging, and many display methods lack a clear representation of subtle changes. In this investigation, detailed high-resolution sampling of a sediment core taken from Cheyenne Bottoms Wildlife Refuge, in central Kansas, was analyzed to catalogue PSD variations. We found that standard statistical representations of data did not accurately represent the subtle fluctuations in PSD over the past several millennia. A new technique was needed to better visualize our data. Using Geosoft software, we were able to more clearly visualize and quantify fine-scale changes in grain size. The result is a straightforward method of analyzing and imaging sediments to obtain useful paleostorm proxy data.