|Title||Ion and sulfate-isotope ratios in arid soils subject to wind erosion in the southwestern USA|
|Publication Type||Journal Article|
|Year of Publication||1988|
|Authors||Schlesinger WH, Peterjohn WT|
|Journal||Soil Science Society of America Journal|
|Keywords||acid rain, aeolian processes, article, articles, biogeochemistry, acid rain, biogeochemistry, calcite, biogeochemistry, gypsium, biogeochemistry, soil chemistry, biogeochemistry, stable isotopes, calcite, desert, gypsum, journal, journals, soil chemistry, stable isotopes|
Our objective was to evaluate the potential for arid-land soil dusts to contribute significantly to the content of SO42- and other ions in precipitation. Soil samples collected at 102 location throughout southwestern USA deserts were extracted with distilled water and analyzed for major ionic constituents and the stable isotope ratios (34S/32S) in soluble sulfate. Most samples were dominated by Ca2+, and HCO3-, and were undersaturated with respect to gypsum. Only a weak correlation was found between Ca2+ and SO42- in samples from upland sites. Median 34 S of soil SO4 was +6.2% compared to +3.9% reported for precipitation. However, the median ratios for CA/SO4 (12.00) and Mg/SO4 (1.84) in soil extracts were much larger than the same ratios in precipitation, suggesting that wind erosion of undisturbed desert soils is not a major source of the SO4 in precipitation. Calcite aerosols from desert soils may act to neutralize acid rain in the western USA.