昆嵛山混合杂岩体的地质特征及成因

昆嵛山混合岩体是胶东东部出露面积最大的岩体,是金牛山金矿带的寄主岩体。野外地质特征以及同位素年代学的研究,确定岩体形成于134.3Ma。但是,在元古代,胶东地区还曾受到栖霞运动的影响,广泛地发生了区域变质作用。岩石学、岩石化学、地球化学等方面的研究结果,表明混合岩的原岩是上地壳沉积岩与来源下地壳或上地幔的火山岩的混合物,岩体由交代-重熔作用形成。混合岩对原岩的许多性质具有明显的继承性。岩体的形成是受牟平—即墨深断裂控制。断裂长期活动所引起的变质作用,混合岩化作用以及成矿作用等地质特征已成为我国东部中生代活动大陆边缘的重要特征之一。

THE GENESIS AND GEOLOGICAL FEATURES OF KUNYUSHAN MIGMATITE COMPLEX

Kunyushan migmatite complex was formed at 134.3 Ma. But, owing to the Qixia movement, extensive regional metamorphism took place in Jiaodong in the Proterozoic Era. According to the study on petrology, petrochemistry, geochemistry, etc., it is suggested that migmatites were formed by metasomatism-remelting; their orginal rock is a mixture of sedimentary rocks from the upper crust and volcanic rocks from the lower crust or upper mantle. Kunyushan complex was controlled by the Mopin-Jimo deep fault. Longterm activity of the deep fault generated metamorphism, migmatization and mineralization, which have become one of the most important features of the Mesozoic active continental margin in East China.