کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4692082 1636775 2014 22 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Paleozoic ophiolitic mélanges from the South Tianshan Orogen, NW China: Geological, geochemical and geochronological implications for the geodynamic setting
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Paleozoic ophiolitic mélanges from the South Tianshan Orogen, NW China: Geological, geochemical and geochronological implications for the geodynamic setting
چکیده انگلیسی


• A mid-ocean ridge (MOR) type affinity for the Guluogou ophiolite
• A SSZ type affinity for the Serikeyayilake and Aertengkesi ophiolites
• A forearc basin existed from ca. 439 Ma to 356 Ma.
• A normal ocean (the South Tianshan Ocean) lasted to ca.332 Ma.

Two ophiolitic mélange belts, the South Central Tianshan Ophiolite Belt (SCTOB) and the South Tianshan Ophiolite Belt (STOB), extend almost parallel to the Chinese South Tianshan Orogen — the southernmost part of the Central Asian Orogenic Belt (CAOB). The SCTOB occurs interlayered in the South Central Tianshan Suture Zone, the STOB as exotic blocks in Palaeozoic sedimentary strata. However, their tectonic settings and ages, which are crucial for understanding the formation of the CAOB, are still controversially discussed. In order to better understand these geological problems, geological, geochemical and geochronological investigations were conducted on the Guluogou (SCTOB) as well as on the Serikeyayilake and Aertengkesi ophiolitic mélanges (STOB). The ophiolitic suites are composed of basalts, gabbros and mantle peridotites. Laser ablation ICP-MS (LA-ICP-MS) U–Pb zircon ages of 334 ± 5 Ma and 332 ± 7 Ma were obtained for the Guluogou gabbros, while SHRIMP U–Pb zircon ages of 423 ± 10 Ma and 423 ± 4 Ma were determined for the Serikeyayilake and Aertengkesi gabbros. The mineral composition of the mantle peridotites and the geochemical characteristics of the basalts suggest a mid-ocean ridge (MOR) type affinity for the Guluogou ophiolite and a SSZ type affinity for the Serikeyayilake and Aertengkesi ophiolites. The present data, combined with previously published results, indicate that the STOB may have been derived from a forearc rifting setting that existed during the early Silurian to the early Carboniferous (ca. 439–356 Ma), whereas the SCTOB may represent fragments of a normal wide ocean that lasted to the early Carboniferous (ca. 332 Ma).

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tectonophysics - Volumes 612–613, 4 February 2014, Pages 106–127
نویسندگان
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