矿物包裹体弹性拉曼频移温压计原理及其地质应用

与目前广泛存在的传统热力学温压计相比,矿物包裹体拉曼弹性温压计是一种独立于化学平衡之外的基于力学平衡的新型温压计。其原理是利用激光拉曼频移标定矿物包裹体在常压条件下储存的残余应力,结合包裹体与寄主两相矿物弹性物理特性,可准确恢复包裹体捕获时的温度和压力条件,是一个潜在的优质温压计。作为新发展起来的技术和方法,越来越多地引起地质学家的关注,但是目前大量的研究还集中于对该温压计自身的推演和校正,而对于天然样品的研究还相对缺乏。近来年,学者们成功地将拉曼弹性矿物温压计应用到各类天然样品的研究中。有限的研究表明拉曼弹性矿物温压计具有较大的应用范围,不仅是一个潜在的优质地质温压计,而且可广泛应用于恢复俯冲带受后期热事件强烈改造的高压-超高压变质信息,进而示踪地球早期俯冲带演化的动力学过程。因此矿物包裹体拉曼弹性温压计具有广泛的地质用途和应用前景。

Principle and geological applicability of the Raman elastic geothermobarometry for mineral inclusion systems

Compared with conventional geothermobarometries, the Raman elastic geotherobarometry for host-inclusion systems is a new method, independent of the chemical equilibrium between coexisting minerals. The residual pressure measured by pressure-dependent Raman spectra of mineral inclusions is combined with elastic modeling to determine the entrapment P and T conditions for a single inclusion in a host mineral. As a newly developed technology and method, the Raman elastic geothermobarometry has gained much attention and potential application; however, a lot of research is still focused on different deduction and calibrations for the geothermobarometry. Research for natural samples is still relatively lacking at present. In recent years, it has prompted applications to geological problems as well as ongoing tests of its validity. The results show that the Raman elastic geothermobarometry can provide new constraints on P-T conditions of multistage metamorphism and tectonic evolution, especially later thermal overprinting due to the continuous re-equilibration of rock-forming and accessory minerals.