Studies On The Preparation Of Nano Amorphous And Intermediate Metastable Phase Of α-Quartz-Graphite And Their High Pressure Synthesis And Phase Transition

Based on the pressure and temperature of experimental transformation ofα-SiO2 to coesite and stishovite and graphite to diamond under high static pressure (HSP), a conjecture that the coesite , stishovite and diamond in the Earth's crust (COSIEC) was formed during the process of a plate subducting into the upper-mantle (coesite :about 90 km, diamond:about130km, stishovite: about400km ), and then exhuming back to the Earth's surface has been made. This hypothesis of plate subduction-exhumation has been put forward to explain the formation of the coesite, stishovite and diamond existing in the Earth's surface in zones of building mountain of the Earth plates. In labs, much work on the synthesis of coesite, stishovite and diamond by a HSP and high temperature, including the effect of the initial state of materials on the synthesis of coesite,...