超高压变质岩中柯石英→石英相变研究的进展

柯石英是石英的高压同质多相变体，是超高压变质作用的产物，它是识别超高压变质作用的重要标志矿物。柯石英的发现表明了近地表的岩石随板块运动曾被俯冲至地下大于90km的深度并经受了超高压变质作用。研究柯石英→石英相变过程中的微结构变化，对进一步研究超高压变质作用的机理及超高压变质岩折返过程的动力学机制具有重要意义。本文简述了近年来有关超高压变质岩中柯石英→石英相变研究的一些进展。

Advance of Study on Coesite→Quartz Transition in Ultrahigh Pressure Metamorphic Rocks

Coesite is a polymorph of silica existed in high pressures. Coesite is the result of ultrahigh-pres sure metamorphism. Coesite is an important mineral often used to judge the ultrahigh-pressure metamorphism. The discovery of coesite bearing rocks indicates that the rocks near the Earth' s surface have been subducted to the depth of more than 90 km by plate movements, and experienced ultrahigh-pressure metamorphism there. Understanding the structural changes during the transition from coesite to quartz is very important for studying the mechanism of the ultrahigh-pressure metamorphism and the kinetic mechanism on how the ultrahigh-pressure metamorphic rocks exhumate to the Earth's surface. This paper reviews briefly some advances of the stud ies on the transition from coesite to quartz in ultrahigh pressure metamorphic rocks.