کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4436318 1310675 2009 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Geomorphic controls on mercury accumulation in soils from a historically mined watershed, Central California Coast Range, USA
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Geomorphic controls on mercury accumulation in soils from a historically mined watershed, Central California Coast Range, USA
چکیده انگلیسی

Historic Hg mining in the Cache Creek watershed in the Central California Coast Range has contributed to the downstream transport of Hg to the San Francisco Bay-Delta. Different aspects of Hg mobilization in soils, including pedogenesis, fluvial redistribution of sediment, volatilization and eolian transport were considered. The greatest soil concentrations (>30 mg Hg kg−1) in Cache Creek are associated with mineralized serpentinite, the host rock for Hg deposits. Upland soils with non-mineralized serpentine and sedimentary parent material also had elevated concentrations (0.9–3.7 mg Hg kg−1) relative to the average concentration in the region and throughout the conterminous United States (0.06 mg kg−1). Erosion of soil and destabilized rock and mobilization of tailings and calcines into surrounding streams have contributed to Hg-rich alluvial soil forming in wetlands and floodplains. The concentration of Hg in floodplain sediment shows sediment dispersion from low-order catchments (5.6–9.6 mg Hg kg−1 in Sulphur Creek; 0.5–61 mg Hg kg−1 in Davis Creek) to Cache Creek (0.1–0.4 mg Hg kg−1). These sediments, deposited onto the floodplain during high-flow storm events, yield elevated Hg concentrations (0.2–55 mg Hg kg−1) in alluvial soils in upland watersheds. Alluvial soils within the Cache Creek watershed accumulate Hg from upstream mining areas, with concentrations between 0.06 and 0.22 mg Hg kg−1 measured in soils ∼90 km downstream from Hg mining areas. Alluvial soils have accumulated Hg released through historic mining activities, remobilizing this Hg to streams as the soils erode.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Geochemistry - Volume 24, Issue 8, August 2009, Pages 1538–1548
نویسندگان
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