Paterson高温高压流变仪及其在岩石流变学中的应用

Paterson Gas-Medium High-Pressure High-Temperature Testing System and its Applications in Rheology of Rocks

地球作为一个动态体系,其内部岩石在各种物理化学条件下变形,形成各种地质构造。在过去的几十年里,得益于相关测试分析手段的不断发展,地球材料的流变学研究取得了许多实验突破,加深了人类对地壳和上地幔岩石变形行为的理解。本文对实验岩石变形装置的技术发展做了扼要的回顾,重点介绍了Paterson高温高压流变仪(HPT)。HPT是一台内部加热气体介质高温(可达～1500℃)高压(高达700MPa)三轴变形装置,与固态介质的Griggs装置相比,更能对温度、围压、差应力和应变进行高精度的测量,从而获得高质量的力学数据。选择不同的驱动系统,HPT可以在压缩、拉伸和扭转模式下进行各种类型的测试,如恒定应变速率,蠕变(恒定应力)和松弛实验等。利用该装置上的孔隙流体模块,还可以自动控制孔隙流体压力并测量进出样品孔隙流体的体积,从而测定实验变形过程中样品的体积变化。因此,HPT是研究矿物岩石的力学行为和物理性质的最佳装置。本文还对HPT在解决各种关键的地质与地球物理问题,如多相岩石的流变学和断裂力学、部分熔融的形成和萃取、脆-韧性转变、动态重结晶和晶格优选定向的发育,以及变形岩石的地震波性质等方面的应用进行了简要的总结。中国科学院广州地球化学研究所最近安装的HPT是目前中国唯一的一台同类仪器,为中国引入了地球科学领域的一项新的高技术,必然会对构造地质学和地球动力学实验研究产生积极的作用。

The Earth is a dynamic system in which rocks deform under various physical and chemical conditions.A continuous improvement of the related testing and analysis techniques during the past decades has enabled the rheology of the Earth materials to be studied successfully in the laboratory and made important advances in the interpretation of natural deformation and structure in the crust and upper mantle.The goal of this paper is to provide a succinct overview on technical developments of experimental rock deformation equipment with a particular focus on the Paterson High-Pressure High-Temperature Testing System（HPT）.The HPT is an internally-heated gas-confining medium high temperature（up to ～1500℃） and high pressure（up to 700MPa） triaxial deformation apparatus.Unlike the solid-medium Griggs apparatus,the HPT can measure temperature,confine pressure,differential stress and strain with great accuracy and precision so that high quality mechanical data can be obtained.The HPT allows various types of tests to be carried out in compression,extension and torsion：constant strain rate,creep（constant stress）,relaxation,etc.,depending on the capabilities of the actuator system fitted.Using the pore fluid system equipped with the apparatus,one can also automatically control the pore fluid pressure and measure the volume of pore fluid entering or leaving the specimen,and subsequently the volume change of the specimen during an experimental deformation.The apparatus is regarded as the most powerful testing tool in the research of mechanical behavior and physical properties of minerals and rocks.This paper also provides a brief summary for the applications of the HPT to address various important geological and geophysical problems such as rheology and fracture mechanics of polyphase rocks,formation and extraction of partial melt,brittle-ductile transition,dynamic recrystallization and development of lattice preferred orientation,and seismic properties of deformed rocks.The recent installation of a HPT in the Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,introduces to China a new high technology in the Earth Sciences,and promises to have a large positive impact on the experimental studies of structural geology,tectonics and geodynamics.