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运用Brey等人和Bertrand等人矿物温压计,计算了甘肃西秦岭新生代钾霞橄黄长岩中石榴石二辉橄榄岩和石榴石二辉岩包体的平衡温压条件.计算结果表明,石榴石二辉橄榄岩和石榴石二辉岩的稳定温度、压力范围分别为1172～1266℃,2.9～3.6GPa和1169～1248℃,2.8～3.2 GPa.两类包体稳定的压力范围均达到或超出尖晶石相橄榄岩稳定的压力条件(2.0～3.0 GPa),进入石榴石相橄榄岩的稳定区.包体的平衡温度达到或超过大洋地温线,并与实验确定的造山作用后岩石圈伸展条件下钾霞橄黄长岩浆的起源温度一致.因此,西秦岭新生代地幔的热状态具有发生钾霞橄黄长岩岩浆作用的条件.包体的岩石矿物学研究及温压计算显示,石榴石二辉岩与石榴石二辉橄榄岩同为本区地幔的组成,因此都可能成为钾霞橄黄长岩的源区岩石.
The temperature and pressure conditions of garnet lherzolite and garnet-dipeptide inclusions of the Cenozoic Kaxiaopriffite in western Qinling of Gansu were calculated by using the thermometers of Brey et al. And Bertrand et al. The calculated results show that the temperature and pressure of garnet lherzolite and The stable temperature and pressure range of garnet-dipenes range from 1172 to 1266 ℃, from 2.9 to 3.6GPa and from 1169 to 1248 ℃, respectively, and from 2.8 to 3.2 GPa.The stable pressure ranges of both types of inclusions reach or exceed the stability of spinel-peridotite (2.0 ~ 3.0 GPa) into the stable zone of garnet peridotite.The equilibrium temperature of the inclusions reached or exceeded the oceanic geothermal line, and compared with the experimental orogenic lithospheric extension, Therefore, the thermal state of the Cenozoic mantle in the West Qinling has the potential for magmatism of Kashupa fossils.The rock mineralogy and temperature-pressure calculation of the enclaves show that the garnet-dike and garnet lherzolites are the same The composition of the mantle in this area may therefore all become the source rocks of the kashupa feldspar.