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木兰山低温高压变质岩中的石英脉及其围岩的矿物组成、变质结构和界面特征的光学显微镜和电子探针研究表明,该石英脉为同构造重结晶脉,经历过低温高压变质作用,其变质温度压力条件与围岩矿物的形成条件相同。透射电镜亚微米纳米尺度分析表明,该石英脉中存在一种已部分转变成α-石英纳米晶的SiO2非晶相,且观察到类似于柯石英假象的胀裂现象。并认为SiO2非晶相的形成及其变化特征可能是大别山高压超高压变质带南缘蓝片岩的一次俯冲和快速折返过程的超显微证据。
The study on the mineral composition, metamorphic structure and interface characteristics of quartz veins and their surrounding rocks in the Mulanshan low-temperature and high-pressure metamorphic rocks shows that the quartz veins are isomorphic recrystallization veins, experienced the metamorphism of low temperature and high pressure, The metamorphic temperature and pressure conditions are the same as those for the formation of surrounding rock minerals. Transmission electron microscopy nanoscale analysis shows that there is a SiO2 amorphous phase partially transformed into α-quartz nanocrystal in the quartz vein, and a phenomenon similar to that of coesite is observed. It is also believed that the formation and variation of SiO2 amorphous phase may be the evidence of subduction and rapid reentry of the blue schist at the southern margin of the UHP metamorphic belt in the Dabie Mountains.