【摘要】 本文以采自大麻坪地区汉诺坝玄武岩中的二辉橄榄岩包体为初始实验物料,在压力1.0～3.0 GPa、温度1350～1550℃条件下进行了部分熔融实验,对实验产物进行了岩相学研究和电子探针成分分析。二辉橄榄岩在1350℃开始熔融,在实验的温度压力范围内,熔融程度为10%～30%。随熔融程度的升高,部分熔融后残余岩石倾向于向富镁、低铁、低钙、低硅的趋势演化,而部分熔融产生的熔体则倾向于富镁、富铁、低铝、低硅的趋势演化。在岩石化学图解上本次实验中二辉橄榄岩部分熔融产生的熔体化学组成与汉诺坝地区拉斑玄武岩的组成相近。随熔融程度升高,熔体具有从苦橄质→玄武质演化的趋势。更多还原

【Abstract】 We performed an experimental study on partial melting of Da-Ma-Ping lherzolite under pressure 1.0~3.0 GPa and temperature 1350~1550 ℃.Experimental products were researched using petrographic microscope and analysed using electron microprobe.We determined the solidus temperatures and pressures and compositions for solid residues and melts.Lherzolites begin melting at 1350 ℃.Degrees of partial melting are 10%~30%.With increasing degree of melting,the compositions of solid residues have a trend with increasing Mg,low Fe,Ca,and Si and compositions of melts varying with increasing Mg,Fe,low Ca,and Si.Chemical composition of melts produced by melting of lherzolite are similar to those of tholeiites in Hannuoba area.Melts in these experiments have a trend evolving from picritic to basaltic composition with increasing degrees of melting.更多还原