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应用锆石Ti温度计、榍石Zr温度计和金红石Zr温度计,对大别造山带超高压变质岩进行了地质测温.结合矿物微区元素地球化学和U-Pb同位素年代学研究,成功区分出大陆俯冲带变质过程中不同成因和不同期次生长的副矿物.大别造山带低温/超高压榴辉岩与中温/超高压榴辉岩之间在锆石U-Pb年龄与Ti含量温度关系上存在显著差异,反映大陆地壳在俯冲过程中至少拆离为两个岩片,在大陆俯冲隧道内发生变质脱水乃至部分熔融.花岗片麻岩中岩浆成因榍石经历榴辉岩相变质作用之后仍能给出新元古代U-Pb年龄,进变质生长榍石在经历“热”折返变质作用后仍能记录早三叠世U-Pb年龄,指示榍石U-Pb体系具有较高的扩散封闭温度,可能高于750-800℃.
The zircon temperature Ti thermometer, zircon limestone thermometer and rutile Zr thermometer were used to conduct geologic temperature measurement of the UHP metamorphic rocks in the Dabie orogenic belt.By analyzing the mineralogical and geochemical U-Pb geochronology, Sub-minerals with different genesis and different stages during the subduction zone metamorphism: Relationship between zircon U-Pb ages and Ti content in the Dabie orogenic belt between low-temperature / ultrahigh-pressure eclogites and medium temperature / ultrahigh pressure eclogites There is a significant difference, which shows that the continental crust is divided into at least two strata in the process of subduction, metamorphic dehydration and even partial melting in the subducted tunnel in China.The magmatic origin of the granitic gneiss is still after eclogite facies metamorphism Can give the Neoproterozoic U-Pb ages, and into the metamorphic growth, the Jurassic can still record the Early Triassic U-Pb ages after experiencing “hot ” reentry metamorphism, indicating that the Jurassic U-Pb system has higher Diffusion seal temperature, may be higher than 750-800 ℃.