Origin of the Ediacaran Weng'an and Kaiyang phosphorite deposits in the Nanhua basin, SW China | |
Haiying Yang; Jiafei Xiao; Yong Xia; Zhuojun Xie; Qinping Tan; Jianbin Xu; Haiyan Guo; Shan He; Shengwei Wu | |
刊名 | Journal of Asian Earth Sciences |
2019 | |
卷号 | 182页码:1-24 |
关键词 | Phosphorite apatite ediacaran doushantuo Formation central Guizhou |
英文摘要 | The Weng’an and Kaiyang phosphorite deposits are located in Central Guizhou, southwestern China, and formed within the Sinian (Ediacaran) Doushantuo Formation. A systematic investigation of the geology, mineralogy, and geochemistry of these phosphorites was conducted to constrain the redox environment, origin, and genetic mechanisms of Ediacaran phosphorite. In the lower ore layer (layer A), the phosphate minerals are mainly globular phosphate intraclasts, which are characterized by special sedimentary and reworking textures, including microgranular sedimentary, isopachous cement, shrinkage crack, and spongy texture. The phosphate minerals from the upper layer (layer B) have microbial phosphate components, namely embryo- and algae-like microfossils. These phosphatic microfossils have biological structures, and both consist of interior structure and isopachous wall. The P2O5 concentration of phosphorites in layer A reach 32.31%, somewhat higher than that in layer B (28.7%), whereas the P content in globular phosphate intraclasts (40.05%) resemble that of the microbial phosphate component (41.19%). Rocks from layer A have “left-inclining” post-Archean Australian shale (PAAS)–normalized rare earth element (REE) distributions, with higher Ce anomalies (Ceanom) ranging from –0.12 to –0.01 (average –0.07). In contrast, rocks from layer B have “hat-shaped” PAAS–normalized REE distributions, with lower Ceanom ranging from –0.32 to –0.23 (average –0.28). These geochemical characteristics suggest that hydrothermal fluids mixed with normal seawater might have contributed to metallogenesis, and the redox environment transitioned from anoxic to oxic from layer A to B. We conclude that the lower Doushantuo globular intraclasts formed by the mechanical reworking of previous phosphatic sediments, which were dominated by the strong mechanical power of seawater. The upper Doushantuo microbial phosphorite, on the other hand, formed by microbially mediated accretionary growth. |
语种 | 英语 |
内容类型 | 期刊论文 |
源URL | [http://ir.gyig.ac.cn/handle/42920512-1/10839] |
专题 | 地球化学研究所_矿床地球化学国家重点实验室 |
作者单位 | 1.State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China 2.University of Chinese Academy of Sciences, Beijing 101408, China 3.University of Chinese Academy of Sciences, Beijing 101408, China |
推荐引用方式 GB/T 7714 | Haiying Yang;Jiafei Xiao;Yong Xia;Zhuojun Xie;Qinping Tan;Jianbin Xu;Haiyan Guo;Shan He;Shengwei Wu. Origin of the Ediacaran Weng'an and Kaiyang phosphorite deposits in the Nanhua basin, SW China[J]. Journal of Asian Earth Sciences,2019,182:1-24. |
APA | Haiying Yang;Jiafei Xiao;Yong Xia;Zhuojun Xie;Qinping Tan;Jianbin Xu;Haiyan Guo;Shan He;Shengwei Wu.(2019).Origin of the Ediacaran Weng'an and Kaiyang phosphorite deposits in the Nanhua basin, SW China.Journal of Asian Earth Sciences,182,1-24. |
MLA | Haiying Yang;Jiafei Xiao;Yong Xia;Zhuojun Xie;Qinping Tan;Jianbin Xu;Haiyan Guo;Shan He;Shengwei Wu."Origin of the Ediacaran Weng'an and Kaiyang phosphorite deposits in the Nanhua basin, SW China".Journal of Asian Earth Sciences 182(2019):1-24. |
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