کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4680629 1634929 2007 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Rhenium-osmium isotope and elemental behaviour during subduction of oceanic crust and the implications for mantle recycling
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
Rhenium-osmium isotope and elemental behaviour during subduction of oceanic crust and the implications for mantle recycling
چکیده انگلیسی
Many ocean-island basalts (OIB) possess radiogenic Os and Pb isotope compositions that have been attributed to the presence of recycled oceanic crust in the mantle source. Published Re-Os data for high-P metabasaltic rocks alone (consistent with this study) have been taken to suggest that excessive amounts of oceanic crust are required to generate such signatures. However, this study shows that gabbro may exert a strong influence on the composition of recycled oceanic crust. Using both gabbro and basalt (i.e. a complete section of oceanic crust) calculations suggest that the presence of ≥ 40% of 2 Ga oceanic crust can generate the radiogenic Os compositions seen in some OIB. Furthermore, lower U/Pb ratios in gabbro (compared to basalt) serve to limit the 206Pb/204Pb ratios generated, while having a minimal effect on Os ratios. These results suggest that the incorporation of gabbro into recycling models provides a means of producing a range of OIB compositions having lower (and variable) 206Pb/204Pb ratios, but still preserving 187Os/188Os compositions comparable to HIMU-type OIB.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Earth and Planetary Science Letters - Volume 253, Issues 1–2, 15 January 2007, Pages 211-225
نویسندگان
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