| Geochemical and chronological constraints on the mantle plume origin of the Caroline Plateau | |
| Zhang, Guoliang1,2,3,4; Zhang, Ji1,2,5; Wang, Shuai1,2,5; Zhao, Jianxin6 | |
| 2020-05-05 | |
| 发表期刊 | CHEMICAL GEOLOGY
 |
| ISSN | 0009-2541 |
| 卷号 | 540页码:13 |
| 通讯作者 | Zhang, Guoliang(zhangguoliang@qdio.ac.cn) |
| 摘要 | The genesis of an oceanic plateau provides important information on the composition and melting dynamics of the deep mantle. The Caroline Rise, consisting of the West and the East Caroline Ridges, has played an important role in the evolution of the subduction system of the western Pacific; however, the nature and origin of the Caroline Rise are poorly known. Here, on the basis of seafloor sampling, we confirm for the first time that the Caroline Rise represents an oceanic plateau (the Caroline Plateau) that formed as a large igneous province. The Caroline Plateau is connected with the Caroline Seamount Chain to the east, and the seamount chain formed above a deep-rooted hotspot. To investigate the nature of the mantle source of the Caroline Plateau and its genetic relationship with the Caroline Seamount/Island Chain, we age-dated basalt samples from the Caroline Plateau and analyzed their major and trace elements and Sr-Nd-Pb-Hf isotopes. The samples can be classified as alkali or tholeiitic basalt. The tholeiitic basalts (15.62 +/- 3.16 to 19.26 +/- 0.35 Ma) are older than the alkali basalts (8.13 +/- 0.81 Ma) and the volcanics of the Caroline Seamounts/Islands to the east. The tholeiitic basalts have trace element patterns similar to those of basalts of the Ontong Java Plateau. We suggest that the tholeiitic basalts represent the main stage of volcanism on the Caroline Plateau and the alkali basalts the late stage. The alkali basalts of the plateau have isotopic compositions similar to those of the basalts of the Caroline Islands, indicating an origin from the same enriched mantle end-member. The tholeiitic basalts with a MORB-like depleted geochemistry indicate the involvement of depleted components in their mantle source, and the Sr-Nd-Pb-Hf isotope compositions of the tholeiitic basalts can be reproduced by mixing alkali basalt with a depleted MORB mantle component. Based on the relatively low Sm/Yb ratios of the two groups of basalts, the Caroline Plateau is inferred to have formed on a young Caroline Plate with a thin lithosphere. We suggest that the geochemistry and ages of formation of volcanic rocks in the Caroline Plateau/Seamount system can be explained by the activities of the Caroline hotspot. The volcanic rocks of the Caroline Plateau and Islands show increasing alkalinity and Sm/Yb ratios with time, which reflect thickening of the lithosphere and decreasing activity of the Caroline mantle plume. |
| 关键词 | Alkali basalt Age dating Geochemistry Hotspot Mantle plume Caroline Plateau |
| DOI | 10.1016/j.chemgeo.2020.119566 |
| 收录类别 | SCI |
| 语种 | 英语 |
| 资助项目 | National Natural Science Foundation of China[91858206] ; National Natural Science Foundation of China[41876040] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDA220500101] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDA11030103] ; Taishan Scholars Program of Shandong Province ; Senior User Project of RV KEXUE Altis, 1999[KEXUE2018G09] |
| WOS研究方向 | Geochemistry & Geophysics |
| WOS类目 | Geochemistry & Geophysics |
| WOS记录号 | WOS:000525365400003 |
| 出版者 | ELSEVIER |
| 引用统计 | |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://ir.qdio.ac.cn/handle/337002/167203 |
| 专题 | 海洋地质与环境重点实验室 深海极端环境与生命过程研究中心 |
| 通讯作者 | Zhang, Guoliang |
| 作者单位 | 1.Chinese Acad Sci, Ctr Deep Sea Res, Inst Oceanol, Qingdao 266071, Peoples R China 2.Chinese Acad Sci, Key Lab Marine Geol & Environm, Inst Oceanol, Qingdao 266071, Peoples R China 3.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Geol, Qingdao 266000, Peoples R China 4.Chinese Acad Sci, Ctr Ocean Megasci, Qingdao 266071, Peoples R China 5.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 6.Univ Queensland, Ctr Microscopy & Microanal, Radiogen Isotope Lab, Brisbane, Qld 4072, Australia |
| 第一作者单位 | 中国科学院海洋研究所; 中国科学院海洋大科学研究中心 |
| 通讯作者单位 | 中国科学院海洋研究所; 中国科学院海洋大科学研究中心 |
| 推荐引用方式 GB/T 7714 | Zhang, Guoliang,Zhang, Ji,Wang, Shuai,et al. Geochemical and chronological constraints on the mantle plume origin of the Caroline Plateau[J]. CHEMICAL GEOLOGY,2020,540:13. |
| APA | Zhang, Guoliang,Zhang, Ji,Wang, Shuai,&Zhao, Jianxin.(2020).Geochemical and chronological constraints on the mantle plume origin of the Caroline Plateau.CHEMICAL GEOLOGY,540,13. |
| MLA | Zhang, Guoliang,et al."Geochemical and chronological constraints on the mantle plume origin of the Caroline Plateau".CHEMICAL GEOLOGY 540(2020):13. |
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| Geochemical and chro（4419KB） | 期刊论文 | 出版稿 | 限制开放 | CC BY-NC-SA | 浏览 | |
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