高温高压条件下蛇纹岩电导率的测定结果及其在地震研究中的意义①

地震 ›› 1998, Vol. 18 ›› Issue (S1): 53-57.

高温高压条件下蛇纹岩电导率的测定结果及其在地震研究中的意义^①

高平

中国北京 100029 中国地震局地质研究所

收稿日期:1998-06-03 修回日期:1998-06-23 出版日期:1998-10-20 发布日期:2022-09-30
作者简介:高平,女,1941年1月出生,副研究员,主要从事热力学和高温高压岩石物理性质等研究工作。
基金资助:
①中国地震局地质研究所论著98C0003

THE CONDUCTIVITY OF SERPENTINE AT HIGH PRESSURE AND HIGH TEMPERATURE AND ITS SIGNIFICANCE IN EARTHQUAKE RESEARCH

Gao Ping

Institute of Geology, CSB, Beijing 100029, China

Received:1998-06-03 Revised:1998-06-23 Online:1998-10-20 Published:2022-09-30

摘要/Abstract

摘要： 通过高温高压实验测量蛇纹岩在不同温压条件下的电导率,压力从200MPa到1100MPa,温度从100℃到1100℃实验表明,在1 GPa压力范围内,蛇纹石大约在650~700℃范围发生脱水反应。蛇纹石脱水导致电导率升高。其机理是自由水的出现可使岩石周围物质溶解,使得其中离子数量增加,因此会使电导率增大。蛇纹石作为-种重要含水矿物在俯冲带究竟可以被带到地球内部哪个深度,将取决于蛇纹石脱水反应的P-T条件和俯冲带的热结构。水的出现可以使周围岩石在较低温度下,提前出现部分熔融乃至熔融。因此,蛇纹石脱水发生的深度范围能够很好的解释岛弧岩浆的成因及火山热管的来源。并可能是地幔水的重要来源。蛇纹石水解所产生的体积和能量的变化还可能是深层地震发生的重要原因之一。

关键词: 电导率, 高温高压试验, 蛇纹岩

Abstract: The conductivity of serpentine has been experimentally measured at pressure of 200 MPa to 1100 MPa and temperature of 100°C to 1100°C. The results show that within the pressure range of 1 GPa, the dehydration occurs at 650°C to 700°C for serpentine and dehydration causes the increase of conductivity. The mechanism of the conductivity increase is the free water associated with dissolution of surrounding materials. Serpentine is one of the important water-bearing minerals. What depth can it be brought to during subducting of plate? It depends on the P-T conditions of its dehydration and the thermal structure of subduction belt. The emergency of free water can also lead to the occurrence of partial melting or melting at lower temperature. This may explain the genesis of island-arc-magma and the source of volcanic thermotube. The changes of volume and energy during dehydration of serpentine may be one of the important causes for deep seismicity.

Key words: Electric conductivity, High pressure and high temperature test, Serpentine

高平. 高温高压条件下蛇纹岩电导率的测定结果及其在地震研究中的意义^①[J]. 地震, 1998, 18(S1): 53-57.

Gao Ping. THE CONDUCTIVITY OF SERPENTINE AT HIGH PRESSURE AND HIGH TEMPERATURE AND ITS SIGNIFICANCE IN EARTHQUAKE RESEARCH[J]. EARTHQUAKE, 1998, 18(S1): 53-57.