| 布拜图对PACMANUS热液区Si-Fe-Mn-羟基氧化物沉淀条件的指示 |
| |
| 作者姓名： | YANG Baoju ZENG Zhigang WANG Xiaoyuan YIN Xuebo CHEN Shuai |
| |
| 作者单位： | 中国科学院海洋研究所海洋地质与环境重点实验室海底热液活动实验室 青岛 266071;中国科学院大学 北京 100049;中国科学院海洋研究所海洋地质与环境重点实验室海底热液活动实验室 青岛 266071;中国科学院海洋研究所海洋地质与环境重点实验室海底热液活动实验室 青岛 266071;中国科学院海洋研究所海洋地质与环境重点实验室海底热液活动实验室 青岛 266071;中国科学院海洋研究所海洋地质与环境重点实验室海底热液活动实验室 青岛 266071 |
| |
| 基金项目： | The National Key Basic Research Program of China under contract Nos 2013CB429700; the National Special Fund for the 12th Five Year Plan of COMRA under contract Nos DY125-12-R-02 and DY125-12-R-05; the National Natural Science Foundation of China under contract Nos 41325021, 40830849, 40976027 and 41476044; the Shandong Province Natural Science Foundation of China for Distinguished Young Scholars under contract Nos JQ200913; the Strategic Priority Research Program of the Chinese Academy of Sciences under contract No. XDA11030302; the CAS/SAFEA International Partnership Program for Creative Research Teams. |
| |
| 摘 要： | Utilizing Si, Fe and Mn concentrations within the end-member PACMANUS hydrothermal fluid, Si-Fe-MnH_2 O Pourbaix diagrams were constructed at 300°C and 25°C. The Pourbaix diagrams show that the main Si, Fe and Mn oxides species precipitating from the hydrothermal fluid were Si O_2, Fe(OH)_3, Fe_3(OH)_8, Mn_3O_4, and Mn_2O_3 at 25°C. During mixing of hydrothermal fluid with seawater, Si O_2 precipitated earlier than FeMn-oxyhydroxides because of the lower stability boundary. Then Fe(OH)_2 precipitated first, followed by Fe_3(OH)_8 and Fe(OH)_3, and last, small amounts of Mn_3O_4 and Mn_2O_3 precipitated. Fe(OH)_3 was readily deposited in alkaline solution with little influence by Eh. There were many Si-Fe-Mn-concentric particles in the polished sections of the massive precipitates collected from PACMANUS. In the concentric nucleus and ellipsoid, Si oxides precipitated first before the hydrothermal fluid had mixed with seawater. In the concentric nucleus, after the precipitation of Si oxides, the increase of p H and Eh promoted the precipitation of Mn oxides around the Si oxides. In the large ellipsoid, the precipitation of Fe was divided into two periods. In the early period, increase of p H value of hydrothermal fluid produced by low-temperature convection and an input of a small volume of seawater promoted a small amount of Fe(OH)_3 to precipitate in the Si-rich core. In the late period, after complete mixing with seawater and the resultant fluid was close to neutral or slightly alkaline in p H, Fe(OH)_3 was easily precipitated from the solution and distributed around the Si-rich core.
|
| 关 键 词： | Pourbaix图 热液活动区 沉淀条件 氢氧化物 二氧化硅 铁锰 Fe(OH)2 SiO2 |
| 收稿时间： | 2013/7/17 0:00:00 |
| 修稿时间： | 2014/3/26 0:00:00 |
Pourbaix diagrams to decipher precipitation conditions of Si-Fe- Mn-oxyhydroxides at the PACMANUS hydrothermal field |
| |
| YANG Baoju,ZENG Zhigang,WANG Xiaoyuan,YIN Xuebo,CHEN Shuai.Pourbaix diagrams to decipher precipitation conditions of Si-Fe- Mn-oxyhydroxides at the PACMANUS hydrothermal field[J].Acta Oceanologica Sinica,2014,33(12):58-66. |
| |
| Authors: | YANG Baoju ZENG Zhigang WANG Xiaoyuan YIN Xuebo and CHEN Shuai |
| |
| Institution: | 1.Seafloor Hydrothermal Activity Laboratory of the Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;University of Chinese Academy of Sciences, Beijing 100049, China2.Seafloor Hydrothermal Activity Laboratory of the Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China |
| |
| Abstract: | Utilizing Si, Fe and Mn concentrations within the end-member PACMANUS hydrothermal fluid, Si-Fe-Mn- H2O Pourbaix diagrams were constructed at 300℃ and 25℃. The Pourbaix diagrams show that the main Si, Fe and Mn oxides species precipitating from the hydrothermal fluid were SiO2, Fe(OH)3, Fe3(OH)8, Mn3O4, and Mn2O3 at 25℃. During mixing of hydrothermal fluid with seawater, SiO2 precipitated earlier than Fe- Mn-oxyhydroxides because of the lower stability boundary. Then Fe(OH)2 precipitated first, followed by Fe3(OH)8 and Fe(OH)3, and last, small amounts of Mn3O4 and Mn2O3 precipitated. Fe(OH)3 was readily deposited in alkaline solution with little influence by Eh. There were many Si-Fe-Mn-concentric particles in the polished sections of the massive precipitates collected from PACMANUS. In the concentric nucleus and ellipsoid, Si oxides precipitated first before the hydrothermal fluid had mixed with seawater. In the concentric nucleus, after the precipitation of Si oxides, the increase of pH and Eh promoted the precipitation of Mn oxides around the Si oxides. In the large ellipsoid, the precipitation of Fe was divided into two periods. In the early period, increase of pH value of hydrothermal fluid produced by low-temperature convection and an input of a small volume of seawater promoted a small amount of Fe(OH)3 to precipitate in the Si-rich core. In the late period, after complete mixing with seawater and the resultant fluid was close to neutral or slightly alkaline in pH, Fe(OH)3 was easily precipitated from the solution and distributed around the Si-rich core. |
| |
| Keywords: | Si-Fe-Mn-oxyhydroxides PACMANUS hydrothermal field Pourbaix diagrams |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
| 点击此处可从《海洋学报(英文版)》浏览原始摘要信息 |
| 点击此处可从《海洋学报(英文版)》下载免费的PDF全文 |
|
