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对汉诺坝含石榴石下地壳-上地幔包体中主要矿物核部至边部的化学组成进行了详细的电子探针分析。核部至边部的温度-压力变化表明麻粒岩包体记录了增温、增压作用;核部温度>930℃的地幔包体表现出降温、降压特征,核部温度<930℃的地幔包体的温度-压力变化不明显。这些包体记录的最终压力主要为0.9～1.5 GPa。个别麻粒岩包体向榴辉岩相过渡的岩石学特征可能属于增温、增压过程中麻粒岩向榴辉岩转变的中间产物。综合已有研究,我们认为这些包体记录的温度-压力变化反映了它们被玄武岩捕获前经历的一次重要的岩石圈减薄作用及之前的岩石圈加厚作用。
The chemical composition of the core to the edge of the major minerals in the Hannuoba-containing garnet lower crust-upper mantle crust was analyzed electronically in detail. The temperature-pressure changes from core to margin indicate that the granulite inclusions recorded warming and supercharging effects. The mantle inclusions with core temperature> 930 ℃ exhibited cooling and depressurization characteristics. The core temperature <930 ℃ The temperature-pressure changes of the mantle inclusions are not obvious. The final pressure recorded by these inclusions is mainly 0.9-1.5 GPa. The petrological characteristics of the transition from individual granulite inclusions to eclogite facies may belong to the intermediate products of granulites transitioning to eclogites during warming and pressurization. Based on the previous studies, we believe that the temperature-pressure changes recorded by these inclusions reflect an important lithospheric thinning that they experienced before basaltic trapping and their previous lithospheric thickening.