کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6440451 1638653 2016 20 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Localized occurrences of granulite: P-T modeling, U-Pb geochronology and distribution of early-Sveconorwegian high-grade metamorphism in Bamble, South Norway
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Localized occurrences of granulite: P-T modeling, U-Pb geochronology and distribution of early-Sveconorwegian high-grade metamorphism in Bamble, South Norway
چکیده انگلیسی
New localities of granulite in the Bamble lithotectonic domain of south Norway illustrate localized distribution of granulite facies rocks in an amphibolite facies gneiss terrain. U-Pb zircon SIMS data constrain the magmatic age of the protoliths to be both 1545 ± 7 to 1542 ± 5 Ma and 1149 ± 8 Ma. They provide a robust date of 1139 ± 11 Ma for metamorphic zircon, supporting available estimates for early-Sveconorwegian metamorphism in Bamble. P-T modeling using Grt + Opx ± Cpx + Pl + Bt + Qz-assemblages yields pressures up to 1.15 GPa and T > 850°C. Clinopyroxene-free granulite assemblages are preserved in low-strain lenses, while high-strain granulite shows crystallization of clinopyroxene. The replacement of orthopyroxene by amphibole illustrates hydration and reequilibration at amphibolite facies. The new findings in Bamble show that granulite-facies rocks occur unevenly distributed in high-grade metamorphic terrains and that relationship between granulite and amphibolite facies is complex and irregular. It suggests that factors as fluid availability, deformation and whole-rock composition are important for metamorphic evolution in addition to pressure and temperature gradients.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Lithos - Volumes 240–243, January 2016, Pages 84-103
نویسندگان
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