Disequilibrium melting of recycled phosphate-rich crust in Yunkai Massif, South China
文献类型：期刊论文
| 作者 | Ma, Zhiwang2,4; Guo, Feng1,3,4; Zhao, Liang1,4; Huang, Xin1,4; Wen, Yaqian1,4; Zhang, Feng1,4 |
| 刊名 | LITHOS
 |
| 出版日期 | 2024-06-01 |
| 卷号 | 474页码:16 |
| 关键词 | Disequilibrium melting Apatite geochemistry Phase equilibrium modeling Caledonian S-type granites Yunkai Massif |
| ISSN号 | 0024-4937 |
| DOI | 10.1016/j.lithos.2024.107592 |
| 英文摘要 | We conduct a comprehensive study including bulk -rock and mineral geochemical analyses, Rhyolite-MELTS and phase equilibrium modeling on Caledonian (422-436 Ma) granitic plutons from the Yangchun region of Yunkai Massif, South China, aiming to estimate the melting P-T-H 2 O conditions and decipher the mechanism for crustal anatexis. These rocks are typical S -type granites with presence of muscovite and garnet, resembling those plutons in the European Variscan Belt. The Rhyolite-MELTS modeling yields a crystallization sequence of quartz, plagioclase, K -feldspar, biotite and muscovite. Apatite shows homogeneous texture and occurs as columnar euhedral to subhedral crystal hosted in plagioclase and mica. Further Nd isotope analyses on apatite yield highly nonradiogenic Nd compositions with an e Nd (t) from -14.3 to -8.2 and a T DM2 Nd range of 1.83-2.33 Ga, which are obviously less radiogenic than the bulk -rock e Nd (t) (-8.4 - -7.1) and T DM2 Nd (1.75-1.85 Ga). The zircon crystals span a wide e Hf (t) range from -13.0 to +0.8 and T DM2 Hf range of 1.36-2.22 Ga. The remarkable Nd isotopic difference between the bulk granite and apatite, systematic bulk -rock e Nd (t) variations against SiO 2 , P 2 O 5 and Sm/Nd, and the large e Hf (t) variation of zircon in these S -type granites are likely attributed to disequilibrium melting of Proterozoic heterogeneous crust, during which residual garnet and apatite had been variably entrained in the anatectic melt. Further phase equilibrium modeling indicates that the melting conditions of Yangchun S -type granites include metasedimentary protoliths, -5.0 wt% water, P = 6-7 kbar, T = 700-800 degrees C, with a geothermal gradient of 35-40 degrees C/km. The estimated residual apatite and garnet are 0.07-0.10 wt% and 3.8-9.0 wt% in the protoliths, respectively. The combined results therefore suggest a relatively hot crust across the Yunkai Massif, probably due to mantle upwelling and crustal extension during early to middle Silurian. |
| WOS研究方向 | Geochemistry & Geophysics ; Mineralogy |
| 语种 | 英语 |
| WOS记录号 | WOS:001218545500001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/76994]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 通讯作者 | Guo, Feng |
| 作者单位 | 1.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing 100049, Peoples R China 2.Nanjing Univ, Sch Earth Sci & Engn, State Key Lab Mineral Deposits Res, Nanjing 210023, Peoples R China 3.Chinese Acad Sci, Excellence Ctr Deep Earth Sci, Guangzhou 510640, Peoples R China 4.Chinese Acad Sci, State Key Lab Isotope Geochem, Guangzhou Inst Geochem, Guangzhou 510640, Peoples R China |
| 推荐引用方式 GB/T 7714 | Ma, Zhiwang,Guo, Feng,Zhao, Liang,et al. Disequilibrium melting of recycled phosphate-rich crust in Yunkai Massif, South China[J]. LITHOS,2024,474:16. |
| APA | Ma, Zhiwang,Guo, Feng,Zhao, Liang,Huang, Xin,Wen, Yaqian,&Zhang, Feng.(2024).Disequilibrium melting of recycled phosphate-rich crust in Yunkai Massif, South China.LITHOS,474,16. |
| MLA | Ma, Zhiwang,et al."Disequilibrium melting of recycled phosphate-rich crust in Yunkai Massif, South China".LITHOS 474(2024):16. |
入库方式： OAI收割
来源：广州地球化学研究所
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