辽北凡河坳拉谷及其对铅-锌矿的控制作用

辽北地区中,上元古宙凡河群,据其总的构造样式;近万 m 厚的沉积—火山建造;厚度巨大的细碧岩及其与硅质岩、英安岩、凝灰岩和火山角砾岩组合;非补偿性和补偿性堆积的双层结构;平行裂陷槽延伸方向的生长性断裂和重力梯级带,以及拉伸角砾岩带、滑塌构造、碳酸盐岩的浊积岩系等,表明凡河群为中、晚元古宙分布于华北地台北缘的坳拉谷沉积。其形成作用可据 Ramberg(1972)的重力不稳定模式来阐明。该坳拉谷构造作用的早期阶段控制了关门山铅—锌矿田的成矿和分布。对该坳拉谷构造及成矿作用的研究无疑对关门山矿田新一轮找矿和靶区分析是有稗益的,同时对整个华北地台北缘构造演化研究也具有一定意义。

FANHE AULACOGEN AND STRUCTURE CONTROLLING LEAD-ZINC ORE DEPOSITS IN NORTHERN LIAONING PROVINCE

Mid-Late Proterozoic Fanhe Group in northern Liaoning, which based on itsgeneral structure form;the distribution of sedimentary-volcanic formation with hugethickness near 10000m;the eruption of thick spilite and the special association ofspilite and silicolites, dacite, tuff and volcanic braccia; double-layered structure ofcompensational sediments and noncompensational sediments;growth faults, gravitygradient zone along extend direction of the aulacogen and the braccia zone of extentionzone, slumping structure;turbidity series of carbonatite etc, indecate that is as aMid-Late proterozoic aulacogen distributed along the northern margin of NorthChina Platform.The formation of Fanhe aulacogen might be stated on basis of non-stationary model of gravity by Ramberg (1972). The mineralization and distributionin guanmenshan Pb-Zn ore field were controlled during early stage of the aulacogenstructure. To study the structure pattern consisted of faults and dikes of diabase isusefull for progenosis of ore deposits. So the study on structure and mineralization ofFanhe aulacogen has important signification not only for finding the new ore-depositsin Guanmenshan and miantime for tectonic evolution of northern margin of NorthChina Platform as well.