| Strontium isotopes reveal weathering processes in lateritic covers in southern China with implications for paleogeographic reconstructions | |
| Xiao Wei; Shijie Wang; Hongbing Ji; Zhenhua Shi | |
| 2018 | |
| Source Publication | Plos One
 |
| Volume | 13Issue:1Pages:1-25 |
| Abstract | The isotope ratios of Sr are useful tracers for studying parent material sources, weathering processes, and biogeochemical cycling. Mineralogical and geochemical investigations of two lateritic weathering covers, in an area close to the Tropic of Cancer (Guangxi Province, southern China), were undertaken to study the regional weathering processes and Sr isotopic sources. We found that weathering and decomposition of Rb-and Sr-bearing minerals change the Sr isotopic composition in weathering products (lateritic soils). Weathering of illite lowered the Sr-87/Sr-86 ratio whereas dissolving and leaching of carbonate minerals increased the Sr-87/Sr-86 ratio. An Fe nodular horizon is widely developed on the top of the weathering covers in the studied area and it differs from the lateritic soil horizon in mineral composition, construction, and elemental concentration. Furthermore, both Fe2O3 and P2O5 (concentrations) are negatively correlated with the Sr-87/Sr-86 ratios, suggesting fixation of apatite by Fe oxides is a controlling factor of the Sr isotopic composition in the Fe nodular horizon. The Sr-87/Sr-86 and Nb/Sr ratios imply the contents and proportions of Fe nodules and clay are critical in controlling the changes of Sr isotopic composition in the Fe nodular horizon. The two stages of the weathering process of carbonate rocks are revealed by the Sr-87/Sr-86 versus Nb/Sr diagram. The Sr-87/Sr-86 and Rb/Sr ratios suggest that Sr isotopes in the weathering covers within the studied area are derived mainly from parent rock weathering and that the contributions from allothogenic Sr isotopes are limited. A comparison of Sr isotopic composition signatures in the weathering covers of the studied area and Guizhou Province provided insight into the Sr isotopic source and paleogeographic evolution of southern China. From the Permian to the Triassic, the continental fragment sources of the South China sedimentary basin changed significantly. In the Permian, Southern China presented the paleogeographic pattern that the north was higher (in elevation) than the south. |
| Indexed By | SCI |
| Language | 英语 |
| Document Type | 期刊论文 |
| Identifier | http://ir.gyig.ac.cn/handle/42920512-1/8654 |
| Collection | 环境地球化学国家重点实验室 |
| Affiliation | 1.State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China 2.College of Agriculture, Guizhou University, Guiyang, China 3.Puding Karst Ecosystem Research Station, Chinese Academy of Sciences, Puding, China 4.Civil and environmental engineering school, University of Science and Technology Beijing, Beijing, China 5.Guizhou Geological Survey, Guiyang, China |
| Recommended Citation GB/T 7714 | Xiao Wei；Shijie Wang；Hongbing Ji；Zhenhua Shi. Strontium isotopes reveal weathering processes in lateritic covers in southern China with implications for paleogeographic reconstructions[J]. Plos One,2018,13(1):1-25. |
| APA | Xiao Wei；Shijie Wang；Hongbing Ji；Zhenhua Shi.(2018).Strontium isotopes reveal weathering processes in lateritic covers in southern China with implications for paleogeographic reconstructions.Plos One,13(1),1-25. |
| MLA | Xiao Wei；Shijie Wang；Hongbing Ji；Zhenhua Shi."Strontium isotopes reveal weathering processes in lateritic covers in southern China with implications for paleogeographic reconstructions".Plos One 13.1(2018):1-25. |
| Files in This Item: | ||||||
| File Name/Size | DocType | Version | Access | License | ||
| Strontium isotopes r（12251KB） | 期刊论文 | 作者接受稿 | 开放获取 | CC BY-NC-SA | View Application Full Text | |
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Edit Comment