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柯石英是超高压变质作用的直接标志.柴北缘副片麻岩的锆石中已报道有柯石英包体的存在,但在榴辉岩中还没有发现柯石英保存.通过详细的岩相学观察和拉曼光谱的测定,在柴北缘阿尔茨托山(都兰超高压变质单元南带)的榴辉岩中发现柯石英,这些柯石英在石榴子石中呈包体分布,部分被具有栅状结构的石英替代.这是柴北缘地区首次在榴辉岩中发现柯石英,也与榴辉岩670~730℃和2.7~3.25GPa的温压估算相符合.除柴北缘都兰超高压单元之外,柴北缘其他单元的榴辉岩及相关岩石中还没有发现柯石英及其假象,是否柴北缘普遍经历过超高压变质作用还需进一步研究.
Coke quartz is a direct indicator of UHP metamorphism.Corite inclusions have been reported in the zircons of the paragneiss in the northern margin of the Qaidam.Besides, no coesite has been found in the eclogites.According to detailed petrography Observation and Raman spectroscopy, the coesite was found in the eclogites of the Altun Mountains in the northern Qaidam basin (the southern belt of the Dulan UHP metamorphic unit). These coesite are encrusted in garnet and are partially characterized by Which is the first time that the coesite is found in the eclogite in the northern Qaidam and also coincides with the temperature prediction of the eclogite at 670 ~ 730 ℃ and 2.7 ~ 3.25GPa. In addition to the Dulan UHP In addition, the coesite and its illusion have not been found in other units of eclogites and related rocks in the northern Qaidam Basin. Whether the UHP metamorphism is generally experienced in the northern margin of the Qaidam Basin needs further study.