Petrogenesis of highly fractionated rhyolites in the southwestern Okinawa Trough: Constraints from whole-rock geochemistry data and Sr-Nd-Pb-O isotopes
文献类型：期刊论文
| 作者 | Chen, Zuxing1,3; Zeng, Zhigang1,2; Yin, Xuebo1; Wang, Xiaoyuan1,2; Zhang, Yuxiang1,3; Chen, Shuai1; Shu, Yunchao1,3; Guo, Kun1; Li, Xiaohui1,3 |
| 刊名 | GEOLOGICAL JOURNAL
 |
| 出版日期 | 2019 |
| 卷号 | 54期号:1页码:316-332 |
| ISSN号 | 0072-1050 |
| 关键词 | fractional crystallization magma chamber magma mixing rhyolite southwestern Okinawa Trough Sr-Nd-Pb-O isotopes |
| DOI | 10.1002/gj.3179 |
| 通讯作者 | Zeng, Zhigang(zgzeng@ms.qdio.ac.cn) |
| 英文摘要 | In the southwestern Okinawa Trough, a cluster of approximate 70 submarine volcanoes is located at the cross back-arc volcanic trail (CBVT), with the eruptive products dominated by rhyolites. New whole-rock major and trace element and Sr-Nd-Pb-O isotopic data and previously available geochemistry data of volcanic rocks from this region are presented to determine the petrogenesis of these rhyolites. The rhyolites have high SiO2 (>70.01 wt.%), K2O + Na2O (6.71-7.16 wt.%) contents and differentiation index (DI) values (DI > 93), and are metaluminous to weakly peraluminous (A/CNK = 0.99-1.11) and medium-K calc-alkaline in composition. The relatively low 10(4)*Ga/Al (2.06-2.17) and FeO*/MgO ratios (4.50-6.62), as well as Zr (91-174 ppm) and Zr + Ce + Nb + Y (175-271) contents suggest that the rhyolites, which contain hornblende, are generally similar to those of typical highly fractionated I-type granitoids. The rhyolites show arc-related features such as enrichment in LILEs (Rb, Ba, K), Th, U, Pb, and LREEs ((La/Yb)(N) = 6.21-6.74) and strong depletion in HFSEs (Nb, Ta, P, Ti) with both nearly identical and more enriched isotopic compositions, including epsilon Nd (from -3.2 to -3.5), Sr-87/Sr-86 ratios (0.705552 to 0.705713), delta O-18 values (+8.1 parts per thousand to +8.6 parts per thousand), and Pb isotopic compositions (Pb-206/Pb-204 = 18.568-18.589, Pb-207/Pb-204 = 15.641-15.656, and Pb-208/Pb-204 = 38.848-38.904). Based on these characteristics, we propose that subduction-related basalt magma and crust-derived magma mixed and homogenized within a shallow magma chamber with a homogeneous "base-level" isotopic signature of >0 center dot 7055 (Sr-87/Sr-86) and > -3 (epsilon Nd). This magma would have then experienced the extensive fractional crystallization of minerals, including plagioclase, hornblende, apatite, sphene, and Fe-Ti oxides, to form the CBVT rhyolites. Our geochemical interpretation of the existence of a long-lived, convecting magma chamber beneath the CBVT is also consistent with seismic tomography results. |
| 资助项目 | National Basic Research Program of China[2013CB429700] ; National Natural Science Foundation of China[41325021] ; National Program on Global Change and Air-Sea Interaction[GASI-GEOGE-02] ; International Partnership Program of Chinese Academy of Sciences[133137KYSB20170003] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDA11030302] ; Special Fund for the Taishan Scholar Program of Shandong Province[ts201511061] ; National Special Fund for the 13th Five Year Plan of COMRA[DY135-G2-1-02] ; Qingdao National Laboratory for Marine Science and Technology[2015ASTP-0S17] ; Qingdao National Laboratory for Marine Science and Technology[2015ASKJ03] ; Innovative Talent Promotion Program[2012RA2191] ; Science and Technology Development Program of Shandong Province[2013GRC31502] ; National High Level Talent Special Support Program ; CAS/SAFEA International Partnership Program for Creative Research Teams ; Qingdao Collaborative Innovation Center of Marine Science and Technology |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| 出版者 | WILEY |
| WOS记录号 | WOS:000455038100021 |
| 源URL | [http://ir.qdio.ac.cn/handle/337002/160644]  |
| 专题 | 海洋研究所_海洋地质与环境重点实验室 |
| 通讯作者 | Zeng, Zhigang |
| 作者单位 | 1.Chinese Acad Sci, Inst Oceanol, Seafloor Hydrothermal Act Lab, Key Lab Marine Geol & Environm, Qingdao 266071, Shandong, Peoples R China 2.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Mineral Resources, Qingdao, Shandong, Peoples R China 3.Univ Chinese Acad Sci, Beijing, Peoples R China |
| 推荐引用方式 GB/T 7714 | Chen, Zuxing,Zeng, Zhigang,Yin, Xuebo,et al. Petrogenesis of highly fractionated rhyolites in the southwestern Okinawa Trough: Constraints from whole-rock geochemistry data and Sr-Nd-Pb-O isotopes[J]. GEOLOGICAL JOURNAL,2019,54(1):316-332. |
| APA | Chen, Zuxing.,Zeng, Zhigang.,Yin, Xuebo.,Wang, Xiaoyuan.,Zhang, Yuxiang.,...&Li, Xiaohui.(2019).Petrogenesis of highly fractionated rhyolites in the southwestern Okinawa Trough: Constraints from whole-rock geochemistry data and Sr-Nd-Pb-O isotopes.GEOLOGICAL JOURNAL,54(1),316-332. |
| MLA | Chen, Zuxing,et al."Petrogenesis of highly fractionated rhyolites in the southwestern Okinawa Trough: Constraints from whole-rock geochemistry data and Sr-Nd-Pb-O isotopes".GEOLOGICAL JOURNAL 54.1(2019):316-332. |
入库方式： OAI收割
来源：海洋研究所
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