کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4727979 1640153 2007 18 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Nature of mantle source contributions and crystal differentiation in the petrogenesis of the 1.78 Ga mafic dykes in the central North China craton
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Nature of mantle source contributions and crystal differentiation in the petrogenesis of the 1.78 Ga mafic dykes in the central North China craton
چکیده انگلیسی

Circa 1.78 Ga mafic dyke swarms and some coeval volcanic associations constitute a Large Igneous Province in the central North China craton. The 1st generation of dykes intruded at ca. 1780 Ma and is chemically delineated into 3 groups: the LT Group is gabbroic and has low-Fe–Ti contents, acting as parental magma; the NW Group is high in Fe–Ti-contents and doleritic with an iron-enriched trend; whereas the EW Group is doleritic to andesitic and crystallized from relict siliceous liquids with a silica-enriched trend. They have an EM-I type source and record integral magmatic processes. These include contamination of lithospheric material and assimilation of crustal melts with in-situ crystallization in a magma chamber (the LT Group) and fractional crystallization in magma channels (the NW Group) and even with additional alteration (the EW Group). The 2nd generation is slightly younger (ca. 1760 Ma) and scarcely distributed. It has high-Fe–Ti contents, originated from a mixing source of DM and EM-I types. The dykes could be associated with a palaeo-plume: the 1st generation represents lower mantle melts generated from the plume head, whereas the 2nd generation records extra melts from asthenosphere entrained by the plume tail.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Gondwana Research - Volume 12, Issues 1–2, August 2007, Pages 29–46
نویسندگان
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