Geochronology, Geochemistry and Tectonic Setting of the Bairiqiete Granodiorite Intrusion (Rock Mass) from the Buqingshan Tectonic Mélange Belt in the Southern Margin of East Kunlun
Geochronology, Geochemistry and Tectonic Setting of the Bairiqiete Granodiorite Intrusion (Rock Mass) from the Buqingshan Tectonic Mélange Belt in the Southern Margin of East Kunlun
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DOI：
10.1111/1755-6724.12216
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发表时间：
2014-04
期刊：
影响因子：
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通讯作者：
Zuochen Li;Xianzhi Pei;Rui-Bao Li;Lei Pei;Chengjun Liu;Youxin Chen;Zhanqing Liu;Guochao Chen-Guochao-Ch
中科院分区：
文献类型：
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作者：
Zuochen Li;Xianzhi Pei;Rui-Bao Li;Lei Pei;Chengjun Liu;Youxin Chen;Zhanqing Liu;Guochao Chen-Guochao-Ch
This study focuses on the zircon U–Pb geochronology and geochemistry of the Bairiqiete granodiorite intrusion (rock mass) from the Buqingshan tectonic mélange belt in the southern margin of East Kunlun. The results show that the zircons are characterized by internal oscillatory zoning and high Th/U (0.14–0.80), indicative of an igneous origin. LA–ICP–MS U–Pb dating of zircons from the Bairiqiete granodiorite yielded an age of 439.0 ± 1.9 Ma (MSWD = 0.34), implying that the Bairiqiete granodiorite formed in the early Silurian. Geochemical analyses show that the rocks are medium‐K calc‐alkaline, relatively high in Al2O3 (14.57–18.34 wt%) and metaluminous to weakly peraluminous. Rare‐earth elements have low concentrations (45.49–168.31 ppm) and incline rightward with weak negative to weak positive Eu anomalies (δ5Eu = 0.64–1.34). Trace‐element geochemistry is characterized by negative anomalies of Nb, Ta, Zr, Hf and Ti and positive anomalies of Rb, Th and Ba. Moreover, the rocks have similar geochemical features with adakites. The Bairiqiete granodiorite appears to have a continental crust source and formed in a subduction‐related island‐arc setting. The Bairiqiete granodiorite was formed due to partial melting of the lower crust and suggests subduction in the Buqingshan area of the Proto‐Tethys Ocean.
