کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6440973 1638688 2013 75 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study
چکیده انگلیسی
We use petrological and geochemical variations to investigate the formation of granite magma from migmatites that derived from metasedimentary protoliths. This provides evidence of the processes that occur during the evolution (melting, segregation and crystallization stages) of partially molten terranes, for which particular components: protolith, residuum and melt fractions are identified. Mass balance calculations are used to estimate the degree of partial melting and the degree of melt extraction in migmatites. Petrological and compositional data suggest that migmatites from this region are the result of open system processes and that fluid-absent melting played a major role in the formation of migmatites and leucogranites. The geochemical evidence suggests that the compositional variation within the anatectic rocks from Molinos can be understood as a result of 1) variable degrees of melt-residuum separation and 2) fractional crystallization of the anatectic melt. Compared to the protolith, most of the migmatites have melt-depleted compositions (up to 0.25 of melt extraction). In the same fashion most of the leucosomes represent cumulate products of fractional crystallization. This means that they have lost some liquid of evolved composition and represent evidence of the melt extraction pathways and linkage to the magma ascent conduits.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Lithos - Volume 177, 1 September 2013, Pages 470-491
نویسندگان
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