|Title||Elemental geochemistry of wind-erodible playa sediments, Owens Lake, California|
|Publication Type||Journal Article|
|Year of Publication||2002|
|Authors||Gill T., Gillette D.A, Niemeyer T., Winn R.|
|Journal||Nuclear Instruments and Methods in Physics Research B.|
|Keywords||Aerosols, PIXE, sediment|
Wind erosion of the dried bed (playa) of Owens Lake, California is an extremely intense source of mineral aerosol, transporting dust hundreds of kilometers downwind to critical ecological areas and several cities. A dust-producing site on the playa was studied over a four-year period to document the processes associated with aerosol emission. The playa takes on a variety of sedimentary forms and phases with surface crusts of differing susceptibilities to wind erosion. The sediments are classed into three general categories based on appearance: soft (saline), loose with drifting sand (salt–silt–clay), and hard and clean (silt–clay). Sediment samples were collected over a two-year period as the study site cycled through all three crust types, and the samples were crushed and analyzed by PIXE. The results indicate that visual appearance and sedimentary structure does not correlate with elemental composition. All sediment types contain significant concentrations of various elements including sodium, calcium and silicon. Potentially toxic trace elements are also found in the sediments. All sediment types contain lead and/or arsenic in tens of parts per million, as well as various other heavy metals. Pb and As levels do not clearly correlate with salt content or sediment type. Arsenic levels may be slightly higher in the crusts with loose material present and potentially lower in the clean hard crusts, while Pb was least frequently detected in the samples with loose material. Future research will add mineralogical and stable isotope analyses to correlate with the PIXE data.
|Reprint Edition||Not in File (updated 7/29/2005)|