کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4730966 1640395 2013 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Magmatic and metamorphic development of an early to mid-Paleozoic continental margin arc in the southernmost Central Asian Orogenic Belt, Inner Mongolia, China
ترجمه فارسی عنوان
توسعه مغناطیسی و دگرگونی قوس حاشیه قاره ای در اوایل تا اواسط پالئوزوئیک در کمربند اورگونیکی آسیای مرکزی، مغولستان، چین
کلمات کلیدی
زیرکون، قوس حاشیه قاره، ماگماتیسم، متامورفیسم، کمربند اوراسیایی آسیای میانه، کمربندهای دگرگون شده
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
چکیده انگلیسی

The Bainaimiao arc in Inner Mongolia, China, comprises a weakly metamorphosed volcani-sedimentary sequence and a low-P/T metamorphic complex. In this study we present SHRIMP zircon ages and geochemical data to document the temporal and genetic relationships between these two tectonic units. Zircons from a rhyolite and two dacites (high-K calc-alkaline) of the volcani-sedimentary sequence yielded 206Pb/238U ages of 474 ± 7 Ma, 453 ± 7 Ma and 436 ± 9 Ma respectively, that we interpret as recording the timing of three volcanic arc episodes. Rocks from the low-P/T metamorphic complex yielded zircon ages of 462 ± 11 Ma for a sillimanite gneiss and 437 ± 5 Ma for a plagioclase–hornblende gneiss, reflecting two distinct anatectic events. Also from the low-P/T complex, the protolith age of a metadiorite is 438 ± 2 Ma. A diorite from a weakly deformed diorite–granodiorite pluton in the low-P/T complex has a zircon age of 419 ± 10 Ma that correlates in time with regional collisional magmatism. An undeformed pegmatite dike cutting the low-P/T metamorphic complex has an age of 411 ± 8 Ma, which postdates collision and provides an upper limit for the termination of orogeny. Accordingly, we conclude that the volcani-sedimentary sequence and the low-P/T metamorphic complex evolved coherently in the early to mid-Paleozoic and formed an integral continental margin arc in the southernmost Central Asian Orogenic Belt.


► Thermo-tectonic development of a continental margin arc in the southernmost CAOB.
► The arc investigated consists of a volcanic edifice and a continental basement.
► We provide zircon ages for early to mid-Paleozoic magmatic and metamorphic rocks.
► The southernmost CAOB preserves a relatively complete orogenic system.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Asian Earth Sciences - Volume 72, 10 August 2013, Pages 63–74
نویسندگان
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