【摘要】 位于中国河北省张家口以北的汉诺坝玄武岩,由两类岩性不同的玄武岩组成,它们相间成层、相伴互生,构成变化规律的岩性旋回。两类岩石的一系列稀土元素特征数值和分配型式都表现出既不相同又有变化规律的特征。它们都是上地幔物质部分熔融的产物,据部分熔融定量模式计算认为,本区碱性系列玄武岩和拉斑系列玄武岩分别是上地幔处于不同部位的,既较深处的榴石二辉橄榄岩和其上部的铬尖晶石二辉橄榄岩的低度熔融的产物。更多还原

【Abstract】 Hannorpa Basalts, located at the north of Zhangjiakou,Hebei Province consist of two kinds of basalts of different chemical compositions. These, two kinds of basalts are interbeded and closely associated with each other, and thus give rise to a lithological cycle marked by regular variation in compositions. The characteristic values and the types of distribution of the rare earth elements in both two kinds of basalts show different features but possess a regular variation. They are all the partly melted products of upper mantle materials. The calculation with the formula of part-melting quantitative model suggests that the alkaline basalts and the tholeiitic basalts are the lower grade partly melted products of garnet iherzolite (the lower level)and spinel iherzolite (the overling level) respectively in the upper mantle.更多还原