کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5744323 1618219 2017 17 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Controls on the chemical composition of saline surface crusts and emitted dust from a wet playa in the Mojave Desert (USA)
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Controls on the chemical composition of saline surface crusts and emitted dust from a wet playa in the Mojave Desert (USA)
چکیده انگلیسی


- We compared groundwater and saline-sediment compositions at a Mojave Desert playa.
- Salts and trace elements accumulate in surface crusts where groundwater is <3 m depth.
- Surface-crust compositions are similar to those of local groundwater.
- Salts and trace elements are retained in vadose zone where groundwater is >3 m depth.
- Spatial distribution of groundwater depth influences dust composition.

Saline-surface crusts and their compositions at ephemeral, dry, and drying lakes are important products of arid-land processes. Detailed understanding is lacking, however, about interactions among locally variable hydrogeologic conditions, compositional control of groundwater on vadose zone and surface salts, and dust composition. Chemical and physical data from groundwater, sediments, and salts reveal compositional controls on saline-surface crusts across a wet playa, Mojave Desert, with bearing on similar settings elsewhere. The compositions of chemically and isotopically distinctive shallow (<3 m) water masses are recorded in the composition of associated salts. In areas with deeper and more saline groundwater, however, not all ions are transported through the vadose zone. Retention of arsenic and other elements in the vadose zone diminishes the concentrations of potentially toxic elements in surface salts, but creates a reservoir of these elements that may be brought to the surface during wetter conditions or by human disturbance. Selective wind-erosion loss of sulfate salts was identified by the compositional contrast between surface salt crusts and underlying groundwater. At the sub-basin scale, compositional links exist among groundwater, salt crusts, and dust from wet playas. Across the study basin, however, lateral variations in groundwater and solid-salt compositions are produced by hydrogeologic heterogeneity.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Arid Environments - Volume 140, May 2017, Pages 50-66
نویسندگان
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