Transition from tholeiitic to alkali basalts via interaction between decarbonated eclogite-derived melts and peridotite
文献类型：期刊论文
| 作者 | Xie, Qiuhong9,10; Zhang, Zhaochong9; Foley, Stephen F.8; Chen, Chunfei8; Cheng, Zhiguo9; Wang, Yu7; Kong, Weiliang6; Lv, Yiwen9; Santosh, M.5,9; Jin, Qizhen4 |
| 刊名 | CHEMICAL GEOLOGY
 |
| 出版日期 | 2023 |
| 卷号 | 621页码:121354 |
| 关键词 | MAGNESIUM ISOTOPE FRACTIONATION ASIAN OROGENIC BELT MANTLE SOURCE CHARACTERISTICS KARAMAY OPHIOLITIC MELANGE NW CHINA IMPLICATIONS MAFIC OCEANIC-CRUST WEST JUNGGAR CARBONATED MANTLE BEARING ECLOGITE PHASE-RELATIONS |
| ISSN号 | 0009-2541 |
| DOI | 10.1016/j.chemgeo.2023.121354 |
| 英文摘要 | Intraplate basalts generally show a geochemical continuum from alkali to tholeiitic basalts. However, the genetic link between these two types of rocks has remained controversial. The Early Jurassic Karamay basalts in the West Junggar terrane, southern Central Asian Orogenic Belt (CAOB), erupted to form a small-volume outcrop in the stable continental intraplate region. The basalts are characterized by aphyric textures without any visible phenocrysts. Thus, they are different from the ubiquitous porphyritic-textured intraplate basalts and have a composition close to that of the mantle-derived primary melt. In contrast to chemically and petrographically well-defined alkali and tholeiitic basalts, the Karamay basalts exhibit transitional compositions spanning from alkali (with normative olivine+nepheline and normative olivine+hypersthene) to tholeiitic (with normative quartz+hypersthene), providing an important case to address the geochemical continuum of intraplate basalts. Similar to the alkali basalts in eastern China, the Karamay basalts have isotopic imprints of sedimentary carbonates, i.e., significantly lighter Mg (δ26Mg = ?0.54‰ to ?0.34‰) and heavier Zn (δ66Zn = 0.36–0.46‰) isotopes than the normal mantle. However, they display initial ((87Sr/86Sr)t ratios of 0.7047–0.7051, positive ΕNd(t) values (3.3–4.2) and positive anomalies of Nb-Ta-Ti-Zr-Hf, which are not expected in the case of incorporation of recycled carbonates. This contradiction can be reconciled by considering a decarbonation reaction between carbonates (i.e., dolomite and magnesite) and co-existing eclogite in the subducted oceanic slab at pressure >5 GPa, leaving light Mg and heavy Zn isotope signatures in the stagnant eclogite residue in the deep mantle. Combining the geochemical compositions of our samples with the geologic evidence, and considering the previous results of melt-peridotite reaction experiments, we conclude that the Karamay basalts might have originated from the interaction of silica-rich tholeiitic melt derived from the recycled decarbonated eclogite with fertile peridotite during its ascent. Our study highlights that intraplate alkali basalts, especially silica-rich ones (e.g., with SiO2>45 wt.%), can be transformed from tholeiitic melts through reaction with peridotite mantle, and demonstrates that deeply recycled oceanic crust stagnated in mantle can serve as a main source for alkaline lavas. ? 2023 Elsevier B.V. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000944713200001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/80247]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 作者单位 | 1.Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, Praha 6; 165 02, Czech Republic 2.BIC Brno, Technology Innovation Transfer Chamber, Purkyňova 648/125, Brno; 61200, Czech Republic 3.Brno University of Technology, Faculty of Civil Engineering, Institute of Geotechnics, Veve?í 95, Brno; 602 00, Czech Republic 4.School of Earth and Space Sciences, University of Science and Technology of China, Hefei; 230026, China 5.Department of Earth Science, University of Adelaide, Adelaide; SA; 5005, Australia 6.PetroChina Research Institute of Petroleum Exploration and Development, Beijing; 100083, China 7.State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou; 510640, China 8.School of Natural Sciences, Macquarie University, North Ryde; NSW, Australia 9.State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing; 100083, China 10.Laboratory of Isotope Geology, Institute of Geology, Chinese Academy of Geological Sciences, Beijing; 100037, China |
| 推荐引用方式 GB/T 7714 | Xie, Qiuhong,Zhang, Zhaochong,Foley, Stephen F.,et al. Transition from tholeiitic to alkali basalts via interaction between decarbonated eclogite-derived melts and peridotite[J]. CHEMICAL GEOLOGY,2023,621:121354. |
| APA | Xie, Qiuhong.,Zhang, Zhaochong.,Foley, Stephen F..,Chen, Chunfei.,Cheng, Zhiguo.,...&Zhu, Xiangkun.(2023).Transition from tholeiitic to alkali basalts via interaction between decarbonated eclogite-derived melts and peridotite.CHEMICAL GEOLOGY,621,121354. |
| MLA | Xie, Qiuhong,et al."Transition from tholeiitic to alkali basalts via interaction between decarbonated eclogite-derived melts and peridotite".CHEMICAL GEOLOGY 621(2023):121354. |
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。