Melting of continental crust during subduction initiation: A case study from the Chaidanuo peraluminous granite in the North Qilian suture zone

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	Melting of continental crust during subduction initiation: A case study from the Chaidanuo peraluminous granite in the North Qilian suture zone
	Chen, Yuxiao 1; Song, Shuguang 1; Niu, Yaoling 2,3; Wei, Chunjing 1
刊名	GEOCHIMICA ET COSMOCHIMICA ACTA
	2014-05-01
卷号	132 页码:311-336
通讯作者	Song, SG (reprint author), Peking Univ, Sch Earth & Space Sci, MOE Key Lab Orogen Belts & Crustal Evolut, Beijing 100871, Peoples R China.
英文摘要	The Chaidanuo granite batholith is a similar to 500 km(2) homogeneous, high-level intrusion in the North Qilian oceanic suture zone. Three types of enclaves have been recognized, including (1) supracrustal xenoliths, (2) biotite gneiss that represents restite of the upper crustal melting, and (3) coeval mantle-derived mafic magmatic enclave (MME). The batholith consists dominantly of peraluminous biotite monzogranite with SiO2 69-73 wt.% and A/CNK 1.05-1.28 and shows geochemical affinity with the upper-continental crust, e.g., enrichment of large ion lithophile elements (LILEs; K, Rb, U, Th, Pb), depletion of high field strength elements (HFSEs; Nb, Ta, Ti), P, Eu, and Sr, and enriched Sr ([Sr-87/Sr-86](i), 0.731 to 0.744)-Nd (epsilon(Nd) (t), -6.0 to -7.1) isotopes. Zircon U-Pb dating indicates that this batholith formed at 516-505 Ma, coeval with the MMEs (510 Ma), which represent the early stage of seafloor subduction in the North Qilian suture zone. The Hf isotopic composition of the MME (epsilon Hf (t) = -6.0 to +2.1) is more depleted than that of the host granite (epsilon Hf (t) = -14.8 to -4.7), suggesting mixing of mantle- and crust-derived melts. The inherited zircon cores in the host granite yield an age peak at similar to 750 Ma with a few detritals of 591-1683 Ma. Zircons from a biotite gneiss enclave yield a protolith age of 744 Ma and a metamorphic/melting event at 503 Ma. Sr-Nd isotopic modeling reveals that the batholith was generated by melting of Neoproterozoic granitic rocks with the addition of 10-18% mantle-derived magma. Therefore, peraluminous granite can be produced by melting of crustal materials heated by mantle-derived magmas during the early stage of subduction initiation at the site of a prior passive continental margin. (C) 2014 Elsevier Ltd. All rights reserved.
学科主题	Geochemistry & Geophysics
收录类别	SCI
语种	英语
WOS记录号	WOS:000334832100018
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/23826]
专题	海洋研究所_海洋地质与环境重点实验室
作者单位	1.Peking Univ, Sch Earth & Space Sci, MOE Key Lab Orogen Belts & Crustal Evolut, Beijing 100871, Peoples R China 2.Univ Durham, Dept Earth Sci, Durham DH1 3LE, England 3.Chinese Acad Sci, Inst Oceanol, Qingdao 266071, Peoples R China
推荐引用方式 GB/T 7714	Chen, Yuxiao,Song, Shuguang,Niu, Yaoling,et al. Melting of continental crust during subduction initiation: A case study from the Chaidanuo peraluminous granite in the North Qilian suture zone[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2014,132:311-336.
APA	Chen, Yuxiao,Song, Shuguang,Niu, Yaoling,&Wei, Chunjing.(2014).Melting of continental crust during subduction initiation: A case study from the Chaidanuo peraluminous granite in the North Qilian suture zone.GEOCHIMICA ET COSMOCHIMICA ACTA,132,311-336.
MLA	Chen, Yuxiao,et al."Melting of continental crust during subduction initiation: A case study from the Chaidanuo peraluminous granite in the North Qilian suture zone".GEOCHIMICA ET COSMOCHIMICA ACTA 132(2014):311-336.