کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6435586 1637226 2017 18 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Origin and tectonic setting of the giant Duolong Cu-Au deposit, South Qiangtang Terrane, Tibet: Evidence from geochronology and geochemistry of Early Cretaceous intrusive rocks
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی اقتصادی
پیش نمایش صفحه اول مقاله
Origin and tectonic setting of the giant Duolong Cu-Au deposit, South Qiangtang Terrane, Tibet: Evidence from geochronology and geochemistry of Early Cretaceous intrusive rocks
چکیده انگلیسی


- We present a detailed regional geological investigation at Duolong.
- The ore-associated rocks formed by fractional crystallization of mantle-derived mafic melts and magma mixing of mantle-derived mafic melts and hybrid lower crust-derived felsic melts.
- The deposit formed on the ensialic forearc.

We constrain the origin and tectonic setting of the giant Duolong porphyry-epithermal Cu-Au deposit in the South Qiangtang Terrane of northern Tibet, based on new zircon U-Pb ages and Hf isotopic data, as well as whole-rock major and trace element data from poorly studied ore-associated intrusions in the Duolong area. The LA-ICP-MS zircon U-Pb dating indicates that the ore-associated rocks formed between 121 and 126 Ma. These ore-associated rocks are geochemically similar to low-K tholeiitic M-type granitoids and to mid- to high-K, calc-alkaline I-type granitoids. They have variable and predominantly positive zircon εHf(t) values (− 1.4 to + 15.6) and variable crustal model ages (TCDM(Hf); 176-1122 Ma). Taking into account previous data and the regional geology of the study area, we propose that the ore-associated rocks originated from fractional crystallization of mantle-derived mafic melts and magma mixing of mantle-derived mafic and hybrid lower crust-derived felsic melts, and the hybrid lower crust included a mix of juvenile and older continental material. The Duolong porphyry-epithermal Cu-Au deposit formed within an 'ensialic forearc' of an active continental margin as a result of the northwards subduction of the Bangong-Nujiang Ocean crust beneath the South Qiangtang Terrane.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ore Geology Reviews - Volume 80, January 2017, Pages 61-78
نویسندگان
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