Late Cretaceous (ca. 90 Ma) adakitic intrusive rocks in the Kelu area, Gangdese Belt (southern Tibet): Slab melting and implications for Cu-Au mineralization
文献类型：期刊论文
| 作者 | Jiang, ZQ ; Wang, Q ; Li, ZX ; Wyman, DA ; Tang, GJ ; Jia, XH ; Yang, YH |
| 刊名 | JOURNAL OF ASIAN EARTH SCIENCES
 |
| 出版日期 | 2012 |
| 卷号 | 53页码:67-81 |
| 关键词 | Adakite Cu-Au mineralization Slab melting Gangdese arc Tibet |
| ISSN号 | 1367-9120 |
| 通讯作者 | wqiang@gig.ac.cn |
| 中文摘要 | The Gangdese Belt in southern Tibet (GBST) is a major Cu-Au-Mo mineralization zone that mostly formed after the India-Asia collision in association with the small-volume, though widespread, Miocene (18-10 Ma) adakitic porphyries. Cu-Au mineralization has scarcely been found in the regional Jurassic-Early Tertiary batholiths related to subduction of the Neo-Tethyan oceanic plate. Here, we report petrological, zircon geochronological and geochemical data for Late Cretaceous (similar to 90 Ma) intrusive rocks that contain Cu-Au mineralization from the Kelu area in the GBST. These rocks consist of quartz monzonites and diorites. The quartz monzonites, with SiO2 of 58-59 wt.% and Na2O/K2O of 1.1-1.2, are geochemically similar to slab-derived adakites characterized by apparent depletions in heavy rare earth elements (e.g., Yb = 1.4-1.5 ppm) and Y (16-18 ppm) contents, positive Sr but negative Nb and Ti anomalies on multi-element variation diagrams. They have relatively low (Sr-87/Sr-86)(i) (0.7038-0.7039) ratios and high epsilon(Nd)(t) (+3.4 to +3.9) and in situ zircon epsilon(Hf)(t) (+9.3 to +15.8) values. The diorites exhibit high Mg-numbers (0.57-0.61) similar to those of magnesian andesites, and have (Sr-87/Sr-86)(i) (0.7040-0.7041) and epsilon(Nd)(t) (+3.0 to +4.4) values similar to those of the quartz monzonites. We suggest that the quartz monzonitic magmas were most likely generated by partial melting of the subducted Neo-Tethyan basaltic oceanic crust and minor associated oceanic sediments, with subsequent melt-mantle interaction, and the dioritic magmas were mainly derived by the interaction between slab melts and mantle wedge peridotites, with fractionation of apatite and hornblende. These slab-derived adakitic magmas have high oxygen fugacity that may have facilitated Cu-Au mineralization. The close association of the Late Cretaceous adakitic intrusive rocks and Cu-Au mineralization in the Kelu area suggests that the arc magmatic rocks in the GBST may have higher potential than previously thought for Cu-Au mineralization. (C) 2012 Elsevier Ltd. All rights reserved. |
| 学科主题 | Geosciences, Multidisciplinary |
| 语种 | 英语 |
| WOS记录号 | WOS:000306246700008 |
| 公开日期 | 2013-08-28 |
| 源URL | [http://ir.scsio.ac.cn/handle/344004/10327]  |
| 专题 | 南海海洋研究所_中科院边缘海地质重点实验室 |
| 推荐引用方式 GB/T 7714 | Jiang, ZQ,Wang, Q,Li, ZX,et al. Late Cretaceous (ca. 90 Ma) adakitic intrusive rocks in the Kelu area, Gangdese Belt (southern Tibet): Slab melting and implications for Cu-Au mineralization[J]. JOURNAL OF ASIAN EARTH SCIENCES,2012,53:67-81. |
| APA | Jiang, ZQ.,Wang, Q.,Li, ZX.,Wyman, DA.,Tang, GJ.,...&Yang, YH.(2012).Late Cretaceous (ca. 90 Ma) adakitic intrusive rocks in the Kelu area, Gangdese Belt (southern Tibet): Slab melting and implications for Cu-Au mineralization.JOURNAL OF ASIAN EARTH SCIENCES,53,67-81. |
| MLA | Jiang, ZQ,et al."Late Cretaceous (ca. 90 Ma) adakitic intrusive rocks in the Kelu area, Gangdese Belt (southern Tibet): Slab melting and implications for Cu-Au mineralization".JOURNAL OF ASIAN EARTH SCIENCES 53(2012):67-81. |
入库方式： OAI收割
来源：南海海洋研究所
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