石英包体拉曼偏移压力计——一种变质压力计算方法

Raman shifts of quartz inclusions as a geobarometry:A method for calculation of metamorphic pressures

矿物或流体包体可以有效保存寄主矿物生长过程中的化学环境、温度、压力等信息。在高压变质过程中,石榴子石中石英包体的分子振动与环境压力之间具有良好的相关性。根据这一特性,前人提出了石英包体拉曼偏移压力计,其原理是利用显微激光拉曼光谱仪分析石英包体在室温常压下保留的残余压力,再结合石英与寄主矿物的弹性物理特性,恢复石英包体被捕获时的压力,属于矿物物理光谱学压力计,本文介绍了利用石英包体的拉曼位移计算变质压力的基本原理和方法,并对不同方法的适用条件和使用局限做了简要分析。石英包体拉曼偏移压力计是恢复变质岩石形成温度和压力条件的有效方法,具有广泛的应用前景。

It is extremely effective that the mineral or fluid inclusions can preserve the information of either the chemical environment,temperature or pressure,which is during the growth of the host minerals.A good correlation can be proved between the molecular vibration of quartz inclusions in garnet and the ambient pressure,which is during high pressure metamorphism.It has been proposed,a quartz inclusions elastic Raman shift barometer,which is according to this characteristic.The principle is to calibrate the residual pressure by using the microlaser Raman spectrometer analysis of quartz inclusions and then recover the entrapment pressure conditions by combining the elastic modeling of quartz and garnet host.It belongs to the mineral physical spectroscopy barometer.Here,we introduce the basic principle and method of calculating metamorphic pressure by using the Raman shift of quartz inclusion and analyze the applicable conditions and limitations of the difficult method.The quartz inclusion Raman shift barometer is an effective method to restore the formation temperature and pressure of metamorphic rocks and has a wide application prospect.