Abstract

A prominent (4500 km2) dune eld in the Great Plains is the Great Bend Sand Prairie of south-central Kansas. Dunes here overlie late Quaternary alluvium and were reactivated extensively in the late Holocene. Geomorphic and soil evidence suggests that the most likely eolian sand source is the Arkansas River valley to the northwest. Nevertheless, orientations of stabilized dunes indicate that the most recent dune-forming winds came from the south or southwest, in agreement with modern wind data. Mineralogy and trace element concentrations in eolian sands of the Great Bend Sand Prairie are similar to those of the Arkansas River, which permits the Arkansas River as a sediment source. Ca and Sr abundances, which re#ect small amounts of carbonate minerals, are higher in Arkansas River sand compared to eolian sands and show a systematic depletion away from the Arkansas River to the southeast. These trends are likely due to carbonate mineral depletion downwind from abrasion and size reduction. Thus, paleowinds probably were northwesterly during initial deposition. Northwesterly winds occur today when dry, Pacic-derived air is dominant. We hypothesize that the residence time of this air mass was much greater while dunes initially formed, possibly during a warmer and drier mid-Holocene period. ( 2000 Elsevier Science Ltd and INQUA. All rights reserved.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.