Great Plains Prehistoric Megadrought Findings as Potential Indicators for Impending Climate Change-Related Catastrophes
Abstract
Determining details of extreme climate events on the environment is necessary to predict the future effects of global climate change. Researchers studying the northern Great Plains dune systems have found evidence of prolonged prehistoric droughts (megadroughts) that occurred due to climate anomalies. However, the timing, severity, and regional extent of these megadroughts remain controversial. Our previous work supports the interpretation that the White River Badlands (WRB) and the Nebraska Sand Hills (NSH) dune systems reactivated three times in the past 10,000 years in response to global climate change. This study investigates the hypothesis that these dune systems are linked, that sand from the WRB is transported by wind to the NSH, located 60 km southeast of the WRB. To test the hypothesis that these systems are related, we used point-counting methodology to determine modal mineral compositions of 25 samples from the WRB. We compared these results to NSH dune system mineral composition findings from previous studies. Additionally, we compared the geochemical composition of 15 WRB sand samples to data sets from the NSH system using energy dispersive x-ray fluorescence analysis. Our results falsify our hypothesis that the systems are linked geologically, and instead suggest that the systems have distinct geologic histories. Nonetheless, our previous work indicates that these systems are linked climatologically, implying that global climate change could cause these dune systems to reactivate in the future. Should this occur, it could potentially trigger the onset of catastrophic climate-related events across the Great Plains.
Faculty Sponsors
Dr. Paul Baldauf
Project Type
Event
Location
Alvin Sherman Library
Start Date
4-6-2021 12:00 PM
End Date
4-9-2021 12:00 PM
Great Plains Prehistoric Megadrought Findings as Potential Indicators for Impending Climate Change-Related Catastrophes
Alvin Sherman Library
Determining details of extreme climate events on the environment is necessary to predict the future effects of global climate change. Researchers studying the northern Great Plains dune systems have found evidence of prolonged prehistoric droughts (megadroughts) that occurred due to climate anomalies. However, the timing, severity, and regional extent of these megadroughts remain controversial. Our previous work supports the interpretation that the White River Badlands (WRB) and the Nebraska Sand Hills (NSH) dune systems reactivated three times in the past 10,000 years in response to global climate change. This study investigates the hypothesis that these dune systems are linked, that sand from the WRB is transported by wind to the NSH, located 60 km southeast of the WRB. To test the hypothesis that these systems are related, we used point-counting methodology to determine modal mineral compositions of 25 samples from the WRB. We compared these results to NSH dune system mineral composition findings from previous studies. Additionally, we compared the geochemical composition of 15 WRB sand samples to data sets from the NSH system using energy dispersive x-ray fluorescence analysis. Our results falsify our hypothesis that the systems are linked geologically, and instead suggest that the systems have distinct geologic histories. Nonetheless, our previous work indicates that these systems are linked climatologically, implying that global climate change could cause these dune systems to reactivate in the future. Should this occur, it could potentially trigger the onset of catastrophic climate-related events across the Great Plains.
