Recycled Carbonate-Bearing Silicate Sediments in the Sources of Circum-Mediterranean K-Rich Lavas: Evidence From Mg-Zn Isotopic Decoupling
文献类型：期刊论文
| 作者 | Shu, Zi-Tan; Liu, Sheng-Ao; Prelevic, Dejan; Foley, Stephen; Wang, Yu F.; Cvetkovic, Vladica; Li, Shuguang |
| 刊名 | JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
 |
| 出版日期 | 2023 |
| 卷号 | 128期号:3页码:e2022JB025135 |
| 关键词 | ULTRAPOTASSIC IGNEOUS ROCKS MANTLE SOURCE VOLCANIC-ROCKS PETROLOGICAL CHARACTERIZATION LITHOSPHERIC MANTLE SOURCE COMPONENTS TRACE-ELEMENTS MAFIC ROCKS ZINC FRACTIONATION |
| ISSN号 | 2169-9313 |
| DOI | 10.1029/2022JB025135 |
| 英文摘要 | The high flux of subaerial volcanic CO2 emissions around the circum-Mediterranean region requires the involvement of an unusually carbon-rich reservoir, but the origin of which is still unclear. Here, we aim to resolve this problem by analyzing Mg and Zn isotopes for the widely distributed mafic potassic to ultrapotassic lavas in this region. These K-rich lavas have lower delta Mg-26 but similar delta Zn-66 compared to mid-ocean ridge basalts (MORB). No known magmatic processes can explain the isotopic data, which must therefore be characteristics of the mantle sources. Recycled carbonate sediments are capable of explaining the low delta Mg-26, but they typically also have high delta Zn-66. Thus, the low delta Mg-26 but unfractionated delta Zn-66 of these K-rich lavas define Mg-Zn isotopic decoupling which has not yet been observed for other types of mantle-derived lavas. The carbonate-bearing silicate sediments analyzed here possess low delta Mg-26 and MORB-like delta Zn-66, which can account for the Mg-Zn isotopic decoupling. Therefore, the nature of recycled materials (carbonates vs. carbonate-bearing silicate sediments) in the mantle can be distinguished by the coupling or decoupling of Mg and Zn isotopes of mantle-derived magmas. The input flux of carbon from the sediments to the lithospheric mantle is estimated to be similar to 8.1 Mt/yr, and similar to 22.4 Mt/yr of CO2 emissions are predicted, which fit well with the observed output flux of 20.1 +/- 13.4 Mt/yr. Our results demonstrate that recycled crustal carbon stored in the lithospheric mantle is an important source for the extensive subaerial volcanic CO2 emissions in the circum-Mediterranean region. Plain Language Summary Extensive volcanic CO2 emissions around the circum-Mediterranean region constitute a significant proportion of the global total, but the source of this carbon-rich reservoir is unclear. We analyze Mg and Zn isotopes for the widespread, lithospheric mantle-derived K-rich lavas in this region and find that they have lower Mg but similar Zn isotopic data compared to mid-ocean ridge basalts. This Mg-Zn isotopic feature is defined as Mg-Zn isotopic decoupling and explained as resulting from recycled carbonate-bearing sediments in their mantle sources. Thus, the lithospheric mantle beneath the circum-Mediterranean region is carbon-rich, providing an important source for the extensive volcanic CO2 emissions. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000940326000001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/80392]  |
| 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 | Shu, Zi-Tan,Liu, Sheng-Ao,Prelevic, Dejan,et al. Recycled Carbonate-Bearing Silicate Sediments in the Sources of Circum-Mediterranean K-Rich Lavas: Evidence From Mg-Zn Isotopic Decoupling[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2023,128(3):e2022JB025135. |
| APA | Shu, Zi-Tan.,Liu, Sheng-Ao.,Prelevic, Dejan.,Foley, Stephen.,Wang, Yu F..,...&Li, Shuguang.(2023).Recycled Carbonate-Bearing Silicate Sediments in the Sources of Circum-Mediterranean K-Rich Lavas: Evidence From Mg-Zn Isotopic Decoupling.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,128(3),e2022JB025135. |
| MLA | Shu, Zi-Tan,et al."Recycled Carbonate-Bearing Silicate Sediments in the Sources of Circum-Mediterranean K-Rich Lavas: Evidence From Mg-Zn Isotopic Decoupling".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 128.3(2023):e2022JB025135. |
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。