【摘要】 花岗岩的壳幔混合物源成因及花岗岩中暗色微粒包体的成因信息是地质学关注的重要研究对象,但至今还没有适用于花岗岩中暗色微粒包体这种基性矿物组合的压力计。依据Patino Douce模拟壳幔岩浆混合过程的试验岩石学研究资料,发现具有基性矿物组合的暗色微粒包体中单斜辉石的Na、Al含量与压力密切相关,得出了压力与单斜辉石中的Na2O含量、Al2O3含量、硬玉分子摩尔分数、契尔马克辉石分子摩尔分数、硬玉分子与契尔马克辉石分子摩尔分数之和的线性关系,以及压力与斜方辉石中Al2O3含量的线性关系,进而得出适用于壳幔混合物源成因花岗岩中暗色微粒包体的有效地质压力计。这一压力计为了解壳幔混合物源成因花岗岩浆形成的深度提供了研究手段。将地质压力计应用于西秦岭天水地区车河花岗岩体及其中的暗色微粒包体研究,对了解壳幔混合作用形成的花岗岩等深部地质问题具有重要意义。更多还原

【Abstract】 The origin of granite from crust-mantle mixed source and the genesis information of mafic microgranular enclaves(MMEs)in this kind of granite are important objects for geological studies.However,there is no geobarometer for the MMEs which have mafic mineral assemblage.According to the research materials of experimental petrology for simulating the process of crustmantle magma mixing by Patino Douce,it is discovered that the contents of Na and Al in clinopyroxene from the MMEs are closely correlated to pressure.It yields linear relationship between pressure and the content of Na2 O,the content of Al2O3,the mole fraction of jadeite,the mole fraction of Tschermak pyroxene molecule and the mole fraction of jadeite and Tschermak pyroxene molecule.There is also linear relationship between pressure and the content of Al2O3 in orthopyroxene.Then,the efficient geobarometer applied to the MMEs in granite originated from crust-mantle mixed source is educed. This geobarometer provides a research mean for understanding the formation depth of the granitic magma originated from crust-mantle mixed source.The geobarometer to the MMEs is applied to Chehe granitic pluton in Tianshui area ofWest Qinling.The significance of this geobarometer is understanding granite originated from crust-mantle mixed source and other deep geological problems.更多还原