【摘要】 <正> 河北汉诺坝碱性玄武岩中的尖晶石二辉橄榄岩包体是一种粗粒结构的岩石。在其主要造岩矿物——橄榄石和二辉石矿物的颗粒之间,发现一种呈板状或填隙状的褐色含水细粒矿物集合体。这种集合体主要由含水镁硅酸盐和橄榄石的高压相——林伍德石(Ringwoodite)组成,其次分散着细粒的金红石和少量尖晶石等,组成了一种极为少见的含水高压矿物组合。更多还原

【Abstract】 A brown fine-grained mineral assemblage in the form of plate and stuffingwas found in the Hannuoba spinel-lherzolite. A series of measurements, inclu-ding X-ray powder diffraction,infrared spectrometry,DTA and electron micro-probe analysis,were made on this assemblage. The results show that the assem-blage consists of the following minerals: hydrous magnesio-silicate minerals,metamorphic chrysotile,ringwoodite, spinel,rutile,forsterite etc. This is a high-pressure hydrous mineral association never reported in lherzolite elsewhere.Based on the compositions and distribution features of the minerals, it issuggested that the fine-grained mineral assemblage was derived from phlogopite,which had been formed early in the upper mantle and was hydrolyzed duringpartial melting.更多还原