中国科学技术大学学报 ›› 2017, Vol. 47 ›› Issue (2): 155-162.DOI: 10.3969/j.issn.0253-2778.2017.02.006

• 原创论文 • 上一篇    下一篇

硅酸盐熔体电导率实验研究及其对地球内部熔融的启示

倪怀玮   

  1. 中国科学院壳幔物质与环境重点实验室,中国科学技术大学地球和空间科学学院,安徽合肥 230026
  • 收稿日期:2016-09-26 修回日期:2016-10-26 出版日期:2017-02-28 发布日期:2017-02-28
  • 通讯作者: 倪怀玮
  • 作者简介:倪怀玮(通讯作者),1981年生,中国科学技术大学地球和空间科学学院教授,中组部“青年千人计划”入选者和国家自然科学基金委优秀青年科学基金获得者.2002年本科毕业于中国科学技术大学,2009年获美国密歇根大学博士学位,2009~2012年任德国拜罗伊特大学BGI研究所博士后.研究领域为实验岩石学和地球化学动力学,主要从事硅酸盐熔体和流体的物理化学性质以及地球内部挥发分方面的实验、计算和理论研究,在Reviews of Geophysics,Earth and Planetary Science Letters,Geochimica et Cosmochimica Acta等国际期刊发表SCI论文20余篇,主持中国科学院B类先导专项子课题和多项国家自然科学基金项目.E-mail: hwni@ustc.edu.cn
  • 基金资助:
    国家自然科学基金(41322015,41402041),中央高校基本科研业务费专项资金

Experimental investigation of electrical conductivity of silicate melts: Implications for melting in Earth’s interior

NI Huaiwei   

  1. CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China
  • Received:2016-09-26 Revised:2016-10-26 Online:2017-02-28 Published:2017-02-28

摘要: 由于硅酸盐熔体的电导率比固相矿物显著提高,地球内部的熔融区域(如岩浆房)在大地电磁测深获得的电性结构中表现出电导率异常.为了制约这些区域的物理化学条件(如熔体比例和熔体的水含量),迫切需要不同成分硅酸盐熔体在各种温度、压力和水含量条件下的电导率测量数据.本文总结了硅酸盐熔体电导率实验研究的进展,指出Na离子和水的含量是影响熔体电导率的关键因素,并以大洋软流圈低速带和长白山天池火山岩浆房为例介绍了实验结果的应用.未来潜在的前沿研究方向包括测量超临界流体(可视为一种高度富水的特殊硅酸盐熔体)的电导率,以及利用电导率突变确定岩石的熔融温度.

关键词: 硅酸盐熔体, 电导率, 部分熔融, 岩浆房

Abstract: As silicate melts are electrically more conductive than solid minerals, molten zones in Earth’s interior, such as magma chambers, show anomalies in electrical structure inversed from magnetotelluric survey. To constrain the physicochemical conditions, such as melt fraction and H2O concentration in the melt, of the molten zones, experimental data are urgently needed as to the electrical conductivity of the various silicate melts at different temperatures, pressures and H2O concentrations. This paper reviews the progress in experimental studies of electrical conductivity of silicate melts. The concentration of Na+ and that of H2O are the key factors in controlling electrical conductivity. Two applications include the oceanic asthenospheric low-velocity zone and the magma chamber beneath the Tianchi Volcano, Changbai Mountain. Potential future research directions include electrical investigation of supercritical fluids, which could be deemed as a special type of H2O-rich silicate melt, and determination of melting temperature by using jump in electrical conductivity as an index.

Key words: silicate melt, electrical conductivity, partial melting, magma chamber