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| Constraints on the origin of adakites and porphyry Cu-Mo mineralization in Chongjiang, Southern Gangdese, the Tibetan Plateau | |
Hu, Yong-bin1,2; Liu, Ji-qiang1,3; Ling, Ming-xing4; Liu, Yan5 ; Ding, Xing4; Liu, Dun-yi5; Sun, Wei-dong6,7,8
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| 2017-11-01 | |
| Source Publication | LITHOS
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| ISSN | 0024-4937 |
| Volume | 292Pages:424-436 |
| Corresponding Author | Sun, Wei-dong(weidongsun@gig.ac.cn) |
| Abstract | Chongjiang is a low-grade porphyry Cu deposit, located in the Gangdese belt, south Tibet. The petrogenesis and geodynamic settings of the Miocene intrusions associated with the deposit remain controversial. This study presents new results on in situ zircon Hf-O isotopic compositions and U-Pb ages, whole rock major and trace elements, and Sr-Nd isotopes for the adakitic intrusions from Chongjiang deposit. The ore-bearing biotite monzogranite porphyry has adakitic characteristics, with enriched large-ion-lithophile elements (LILE) and light rare earth elements (LREE), and depleted in high-field-strength elements (HFSE), P and Ti. LA-ICP-MS zircon U-Pb dating indicates that the ore-bearing and barren adakites were emplaced at 14.9 +/- 0.3 Ma and 12.9 0.3 Ma, respectively. The porphyry is characterized by relatively high initial Sr-87/Sr-88 ratios (0.7059 to 0.7066), and negative whole-rock epsilon(Nd)(t) values (-3.8 to -2.6). Zircon delta(18)0 is slightly higher than mantle values (5.0 to 7.2 parts per thousand), with varied epsilon(Hf)(t) (-1.0 to 7.6). Most of the in situ zircon Hf-O isotopic data plot in a binary mixing trend between MORB and lower continental crust-derived melts. These results indicate contributions from mixing of a mantle-like source (e.g., slab melts) with continental crust. Interestingly, most of the samples plot in the field defined by Dabie adakites (representing partial melting of the lower continental crust), with several samples near/in the circum-Pacific adakite field (representing partial melting of subducted oceanic slabs), which seemingly indicates that Chongjiang adaldtes mostly formed through partial melting of lower continental crust, with a small amount derived from oceanic slab melts. These may be plausibly explained by plagioclase retention in the thickened Tibetan continental crust, which lowers Sr contents in the magmas during crustal assimilation. Such a model is supported by other adakite discrimination diagrams, which all point towards slab melting. Crustal contamination can compellingly explain the low grade of the Chongjiang deposit. Considering the temporal-spatial distribution of porphyry Cu deposits, geochemical characteristics and high oxygen fugacity, we propose that the subducting Ninetyeast Ridge probably played a critical role in controlling the formation of Miocene adakites and porphyry copper deposits in the eastern Gangdese belt. (C) 2017 Elsevier B.V. All rights reserved. |
| Keyword | Porphyry Cu deposit Adakite Chongjiang Gangdese Ninetyeast Ridge |
| DOI | 10.1016/j.lithos.2017.09.012 |
| Indexed By | SCI |
| Language | 英语 |
| Funding Project | National Key R&D Program of China[2016YFC0600408] ; NSFC[91328204] ; NSFC[41421062] ; Zhejiang Provincial Natural Science Foundation[LZ16D060001] |
| WOS Research Area | Geochemistry & Geophysics ; Mineralogy |
| WOS Subject | Geochemistry & Geophysics ; Mineralogy |
| WOS ID | WOS:000416185500028 |
| Publisher | ELSEVIER SCIENCE BV |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.qdio.ac.cn/handle/337002/157309 |
| Collection | 深海极端环境与生命过程研究中心 中国科学院海洋研究所 |
| Corresponding Author | Sun, Wei-dong |
| Affiliation | 1.Chinese Acad Sci, Guangzhou Inst Geochem, CAS Key Lab Mineral & Metallogeny, Guangzhou 510640, Guangdong, Peoples R China 2.Univ Chinese Acad Sci, Beijing 10094, Peoples R China 3.State Ocean Adm, Inst Oceanog 2, SOA Key Lab Submarine Geosci, Hangzhou 310012, Zhejiang, Peoples R China 4.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Guangdong, Peoples R China 5.Chinese Acad Geol Sci, Inst Geol, Beijing, Peoples R China 6.Chinese Acad Sci, Inst Oceanog, Ctr Deep Sea Res, Qingdao 266071, Peoples R China 7.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Mineral Resources, Qingdao 266237, Peoples R China 8.Chinese Acad Sci, CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China |
| Corresponding Author Affilication | Institute of Oceanology, Chinese Academy of Sciences |
| Recommended Citation GB/T 7714 | Hu, Yong-bin,Liu, Ji-qiang,Ling, Ming-xing,et al. Constraints on the origin of adakites and porphyry Cu-Mo mineralization in Chongjiang, Southern Gangdese, the Tibetan Plateau[J]. LITHOS,2017,292:424-436. |
| APA | Hu, Yong-bin.,Liu, Ji-qiang.,Ling, Ming-xing.,Liu, Yan.,Ding, Xing.,...&Sun, Wei-dong.(2017).Constraints on the origin of adakites and porphyry Cu-Mo mineralization in Chongjiang, Southern Gangdese, the Tibetan Plateau.LITHOS,292,424-436. |
| MLA | Hu, Yong-bin,et al."Constraints on the origin of adakites and porphyry Cu-Mo mineralization in Chongjiang, Southern Gangdese, the Tibetan Plateau".LITHOS 292(2017):424-436. |
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