北山南部柳园地区古生代-早中生代大陆地壳增生过程中的岩浆活动与成矿效应

Magmatism and Its Metallogenetic Effects during the Paleozoic-Triassic Continental Crustal Construction in the Liuyuan Area,South Beishan,NW China

北山造山带地处中亚造山带南缘。古生代时期板块构造体制下古亚洲洋的裂解-扩展-消亡与汇聚大陆边缘的俯冲-碰撞-伸展循环造就了其大陆地壳增生与再造演化的基本背景,并形成了一系列记录这些因果演变连续过程的岩浆侵入与喷发事件。在系统总结最近几年积累的年代学和岩石地球化学资料的基础上,以一些带有特定过程印记的标志性岩浆事件为纲领,表征这些古生代岩浆作用形成过程中的地球动力学演变,揭示其所记录的北山南部的多阶段增生与再造演化机制,并初步探讨有利地球动力学过程制约下的岩浆活动引起的成矿效应。

The Beishan orogenic belt, locating in the south of the Central Asian orogenic belt（CAOB）, witnesses a panoramic scenario of continental crustal accretion and reworking in the model of plate tectonics during the Paleozoic-Triassic. It is driven by rifting-spreading-extinction cycle of paleo-oceans and subduction-collision-extension processes at convergent plate margin, with a series of the associated magmatic events. The generation of syn-and post-orogenic granitoids represents horizontal （lateral） and vertical crustal growth. Based on an overview on the geochronological and geochemical data concerning the Paleozoic magmatic rocks from the Liuyuan area, the paper outlines the evolved geodynamic scenarios inherent in these magmatic sequences, reveals multi-stage crustal accretion and reworking mechanism during the Paleozoie continental construction in south Beishan belt and promises magmatic and tectonic reservoirs for metallogenesis.