Early Palaeozoic intracontinental orogeny in South China Block: Insights from migmatites and potassic mafic rocks in southern Guangdong
文献类型：期刊论文
| 作者 | Jia, Xiaohui; Wu, Jun; Tang, Gongjian |
| 刊名 | INTERNATIONAL GEOLOGY REVIEW
 |
| 出版日期 | 2023 |
| 卷号 | 65期号:21页码:3412-3434 |
| 关键词 | PRECAMBRIAN CONTINENTAL-CRUST I-TYPE GRANITE U-PB AGES CATHAYSIA BLOCK HF ISOTOPES ULTRAPOTASSIC ROCKS VOLCANIC-ROCKS YUNKAI MASSIF CALC-ALKALINE PERALUMINOUS GRANITES |
| ISSN号 | 0020-6814 |
| DOI | 10.1080/00206814.2023.2188493 |
| 英文摘要 | The early Palaeozoic orogen in South China is considered as one of the typical examples of intraplate orogens in the world. However, the nature of the orogen, for example, the onset time and the timing of tectonic transition from syn-orogenic compression to post-orogenic extension, are still controversial. Here, we present new zircon U-Pb age and Hf isotope data, and whole-rock geochemical and Sr-Nd isotopic data for migmatites and potassic mafic rocks in southern Guangdong, from the Cathaysia Block, South China. Migmatites consist of metatexite and diatexite, including various amounts of palaeosome, melanosome, and leucosome. Leucosomes from metatexite and diatexite/migmatite granite samples yield consistent U-Pb ages of 451.5 +/- 2.0 Ma to 458 +/- 16 Ma, respectively. Zircon U-Pb dating from two potassic plutons yield consistent crystallization ages of 451-446 Ma. Our new results of field investigation, mineralogy and microstructures, geochronology, and geochemical compositions demonstrate that the protoliths of migmatites are metasedimentary rocks, while metatexites and diatexites are the products of variable degrees of partial melting of the protolith. The potassic rocks have SiO2 contents ranging from 52.5 to 60.2 wt.%, high K2O/Na2O ratios (0.7-1.3), with MgO contents of 3.0-6.2 wt.% and Mg number of 42-57. They have enriched Sr-Nd-Hf isotopic compositions with (Sr-87/Sr-86)(i) ratios of 0.7085-0.7151, e(Nd)(t) values of -9.9 to -6.2, and epsilon(Hf) (t) values of -10.5 to -5.3, indicating that they were generated from an enriched mantle source modified by ancient oceanic subducted sediments. Regional crustal anatexis occurred at about 451 Ma, and the timescale from crustal anatexis to melt homogenization and accumulation spans over an interval of similar to 15 Myr. The association of migmatites and the potassic rocks may form in post-orogenic extension setting. Thus, we suggest that the tectonic transition from syn-orogenic compression to post-orogenic extension occurred by the Late Ordovician (ca. 451-446 Ma) for the early Palaeozoic orogen in South China. |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000950121800001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/80382]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | Jia, Xiaohui,Wu, Jun,Tang, Gongjian. Early Palaeozoic intracontinental orogeny in South China Block: Insights from migmatites and potassic mafic rocks in southern Guangdong[J]. INTERNATIONAL GEOLOGY REVIEW,2023,65(21):3412-3434. |
| APA | Jia, Xiaohui,Wu, Jun,&Tang, Gongjian.(2023).Early Palaeozoic intracontinental orogeny in South China Block: Insights from migmatites and potassic mafic rocks in southern Guangdong.INTERNATIONAL GEOLOGY REVIEW,65(21),3412-3434. |
| MLA | Jia, Xiaohui,et al."Early Palaeozoic intracontinental orogeny in South China Block: Insights from migmatites and potassic mafic rocks in southern Guangdong".INTERNATIONAL GEOLOGY REVIEW 65.21(2023):3412-3434. |
入库方式： OAI收割
来源：广州地球化学研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。