Comparison of sand dune chronologies in the Great Plains and eastern Lake Michigan coastal zone.

详细信息   

• 作者：Kowalski ; Daniel Michael.
• 学历：Master
• 年：2014
• 毕业院校：Michigan State University
• Department：Geography.
• ISBN：9781321138702
• CBH：1563894
• Country：USA
• 语种：English
• FileSize：5132234
• Pages：154

文摘

Extensive deposits of eolian sand occur throughout the Great Plains region as well as along the eastern coastal zone of Lake Michigan. Numerous studies have been conducted on dunes in the Great Plains and along the Lake Michigan coast. Recent research suggests that dunes in both regions were active contemporaneously during the Medieval Warm Period MWP). This finding is interesting because it suggests that broad regional climate patterns may have influenced dunes in both systems. Given the apparent synchroneity in dune systems within the Great Plains and Great Lakes regions during the MWP,this research further compares the chronology of sand dune evolution in both regions during the Holocene. To test this relationship,published literature from both regions was reviewed and all published radiocarbon and luminescence ages reported were logged,including 348 ages from the Great Plains and 246 ages from the Great Lakes region. Ages were used to construct probability density distributions,inform Principal Components Analysis PCA),and construct time-slice maps to compare and contrast dune evolution events over the past 7000 years. Based upon interpretation of the results of this study,dune activation events have likely been taking place in both regions from ~4400 years ago to the present. Given the apparent similarity in dune activity in both regions,the potential of climate factors such as El Nino frequency and SST fluctuations to have major impacts on the evolution of dune systems in both regions is possible.