کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4458598 1620962 2006 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Rare earth element transport and fractionation in small streams of a mixed basaltic–granitic catchment basin (Massif Central, France)
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی اقتصادی
پیش نمایش صفحه اول مقاله
Rare earth element transport and fractionation in small streams of a mixed basaltic–granitic catchment basin (Massif Central, France)
چکیده انگلیسی

We present dissolved load (< 0.45 μm) rare earth element (REE) patterns of small streams from a catchment basin in the Massif Central in order to characterize the individual fractionation stages for the dissolved REE from the source to the catchment outlet. The upper part of the catchment is located on a basalt plateau, followed downstream by deep and narrow valleys with granitic and orthogneissic bedrock. Stream water has basalt-like REE patterns on the basaltic plateau close to the source, followed by a continuous depletion in light REE (La-Sm, LREE) downstream. Strontium and neodymium isotope ratios of stream water demonstrate that the dissolved REE are essentially of basaltic origin, even in the lower, granitic and gneissic part of the catchment. Mixing with gneiss or granite derived REE thus cannot explain the observed evolution of the REE patterns. There seems also to be no link with the calculated speciation of the dissolved REE. In contrast, a correlation between saturation indexes for hematite and La/Yb ratios suggests that REE fractionation is mainly controlled by precipitation of Fe-oxide particles that preferentially remove LREE from solution.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Geochemical Exploration - Volume 88, Issues 1–3, January–March 2006, Pages 336–340
نویسندگان
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