Diverse source materials contributed to a secular increase in 518O for the Paleo-Mesoproterozoic A2-type granites
文献类型：期刊论文
| 作者 | Lu, Gui-Mei2; Xu, Yi-Gang2; Wang, Wei3; Spencer, Christopher J.1; Roberts, Nick M. W.5; Condie, Kent C.4 |
| 刊名 | EARTH AND PLANETARY SCIENCE LETTERS
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| 出版日期 | 2024-09-15 |
| 卷号 | 642页码:9 |
| 关键词 | A 2-type granites Collisional orogen Great Proterozoic Accretionary Orogen Yangtze Block Paleo-Mesoproterozoic |
| ISSN号 | 0012-821X |
| DOI | 10.1016/j.epsl.2024.118885 |
| 英文摘要 | The elevation of 518O in zircon through Earth history has been previously identified as being coeval with the assembly of post-Archean supercontinents. This was interpreted to result from the increasing incorporation of high-518O sediments into magmas due to enhanced crustal thickening and reworking during supercontinent assembly. However, little attention has been paid to the variations of 518O in igneous rocks during the extensional phases of the supercontinent cycle. Given the scarcity of early Paleoproterozoic granites due to the ca. 2.3-2.2 Ga tectono-magmatic lull, we first report a suite of ca. 2.25 Ga granites from the SW Yangtze Block by providing zircon U-Pb-Hf-O isotopes, whole-rock geochemical, and Sm-Nd isotopic analyses to constrain their petrogenesis. The results demonstrate that they are A2-type granite and originated from the partial melting of Meso-Neoarchean igneous crust in a post-collision extensional setting. Integrating these data with a global compilation of Paleo-Mesoproterozoic A2-type granites allows us to further explore secular changes in elemental and isotopic compositions of these granite types. The A2-type granites in this study exhibit mantle-like zircon 518O values, in accord with those from the compiled pre-1.85 Ga A2-type granites. Additionally, the data show a secular increase in zircon 518O for the compiled Paleo-Mesoproterozoic A2-type granites. Similar increasing trends are also observed in various compositional proxies that imply the increasing addition of mafic igneous rocks into magma sources that are likely associated with the back-arc extensional settings of the Great Proterozoic Accretionary Orogen (GPAO). Considering that the compiled post-1.8 Ga A2-type granites have depleted Nd-Hf isotopes, we posit that they were mainly derived from mafic rocks with arc-like geochemical compositions. In this context, the secular increase in zircon 518O for the post-1.8 Ga A2-type granites might reflect the increasing assimilation of altered oceanic crust into the back-arc and inboard magmatic systems of retreating accretionary orogens. In contrast, the compiled ca. 1.85 Ga A2-type granites possess non-radiogenic Hf and elevated O isotopes, indicative of the incorporation of ancient sediments in their magma sources. We suggest that they are most likely generated in a post-collision extensional setting associated with the very early stages of assembly of the Columbia/Nuna supercontinent. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001274315700001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/78168]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 通讯作者 | Lu, Gui-Mei; Xu, Yi-Gang |
| 作者单位 | 1.Queens Univ, Dept Geol Sci & Geol Engn, Kingston, ON K7L 2N8, Canada 2.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China 3.China Univ Geosci, Sch Earth Sci, State Key Lab Geol Proc & Mineral Resources, Wuhan 430074, Peoples R China 4.New Mexico Inst Min & Technol, Dept Earth & Environm Sci, Socorro, NM 87801 USA 5.British Geol Survey, Geochronol & Tracers Facil, Nottingham NG12 5GG, England |
| 推荐引用方式 GB/T 7714 | Lu, Gui-Mei,Xu, Yi-Gang,Wang, Wei,et al. Diverse source materials contributed to a secular increase in 518O for the Paleo-Mesoproterozoic A2-type granites[J]. EARTH AND PLANETARY SCIENCE LETTERS,2024,642:9. |
| APA | Lu, Gui-Mei,Xu, Yi-Gang,Wang, Wei,Spencer, Christopher J.,Roberts, Nick M. W.,&Condie, Kent C..(2024).Diverse source materials contributed to a secular increase in 518O for the Paleo-Mesoproterozoic A2-type granites.EARTH AND PLANETARY SCIENCE LETTERS,642,9. |
| MLA | Lu, Gui-Mei,et al."Diverse source materials contributed to a secular increase in 518O for the Paleo-Mesoproterozoic A2-type granites".EARTH AND PLANETARY SCIENCE LETTERS 642(2024):9. |
入库方式： OAI收割
来源：广州地球化学研究所
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