幔枝构造成矿理论及其找矿实践  

Metallogenic Theory of Mantle Branch Structure and Its Prospecting Practices

作　　者：牛树银 陈超 张福祥 孙爱群 王丰翔 马宝军 张建珍 李凤友 王宝德 许传诗 NIU Shu-yin;CHEN Chao;ZHANG Fu-xiang;SUN Ai-qun;WANG Feng-xiang;MA Bao-jun;ZHANG Jian-zhen;LI Feng-you;WANG Bao-de;XU Chuan-shi(Hebei GEO University,Shijiazhuang 050031,China;Chengde geological team,Chengde 067000,China)

机构地区：[1]河北地质大学,河北石家庄050031 [2]承德市地质队,河北承德067000

出　　处：《河北地质大学学报》2022年第2期1-22,共22页Journal of Hebei Geo University

基　　金：河北省自然科学基金面上项目(D2019403015);河北省高等学校科学技术研究项目(ZD2019003);河北省“三三三人才工程”项目(A202001014);公益性行业科研专项经费项目(200911007);国土资源部重点实验室项目(2013001);国家自然科学基金(40872137)。

摘　　要：幔枝构造是地幔热柱的第三级构造单元,是地幔热柱多级演化在岩石圈浅部的综合表现形式,是重要的成矿控矿构造。研究认为,燕山运动以来,华北东部地区进入了地幔热柱演化阶段,在众多成矿控矿因素中,区域性韧脆性和脆韧性剪切带以及区域性深断裂构造应是成矿作用的主导性因素,它们不仅是成矿流体的运移通道,而且往往成为重要的成矿储矿构造。地球在重力均衡作用和分异作用下,一直进行着物质的垂向分异和水平运动。重力分异作用使地球物质形成地核—地幔—地壳等结构分层,热力作用则使地球物质发生垂向上下运动。由于地球的核—幔界面是液态外核与塑性态下地幔之间存在的过渡(康氏面D")层,两者之间具有巨大的密度差、压力差、温度差、速度差等,从而导致地球物质的热—冷物质循环,在洋壳离散区形成的岩浆上涌带和板块汇聚区形成的俯冲带,构成四维物质循环;陆壳上则形成地幔热柱—地幔冷柱间的物质交换。与此同时,深源含矿流体通过地幔热柱—地幔亚柱—幔枝构造—有利构造扩容带,迁移到幔枝构造的脆韧性—韧脆性主、次级剪切带,侵入岩体的内、外接触带,密集的构造裂隙带,各种脉岩与围岩的接触带等有利部位集聚成矿。华北东部是我国黄金成矿集中区,多个省份黄金地质找矿均取得了重大进展。金矿的形成过程可以概括为:强烈的岩浆—变质杂岩上涌(隆)—上部盖层向外拆离滑脱—断裂构造体系转制—幔枝构造逐渐形成—含矿流体沿断裂快速贯入—成矿物质冷却结晶,形成区域性大型—超大型金矿(区)带。本文仅选研究实例:区域性成矿集聚区—大兴安岭多金属矿的成矿控矿;典型金矿矿床解剖—中山沟金矿构造成矿控矿找矿断裂构造控矿分析—郭家岭幔枝构造及其成矿控矿。探讨成矿作用,总结成矿规律,归纳成矿As an important ore-forming and ore-controlling structure, the mantle branch structure is a third class structural unit and a concrete representation on the crust surface during the multi-stage evolution of mantle plume. It shows that the eastern part of North China has entered the mantle plume evolution stage since the Yanshan movement. Among many ore-forming and orecontrolling factors, regional ductile-brittle and brittle-ductile shear zones as well as regional deep faults should be the dominant factors, which are not only the migration channel for ore-forming fluids, but also often become important ore-forming and oredepositing structures. Under the action of gravity balance and differentiation, the earth’s materials has been differentiating vertically and moving horizontally. Gravity differentiation makes it form structural stratification such as core, mantle and crust, while thermal action makes it move vertically up or down. Because of a huge difference in density, pressure, temperature and velocity between the liquid outer core and the plastic lower mantle, this can easily form a mantle plume and lead to the hot and the cold cycle of the earth’s materials, and constitute a four-dimensional material cycle, which form magma upwelling zone in divergent area and subduction zone in convergence area in the ocean crust, while in the continental crust, form the material exchange between mantle hot plume and mantle cold plume. At the same time, the deep source ore-bearing fluid migrated through the mantle plume—sub mantle plume—branch structure—favorable structural expansion zone, and finally accumulated and mineralized in various favorable structural sections of mantle branch structure, such as brittle-ductile and ductile-brittle primary and secondary shear zones, in the inner and outer contact zones of intrusive rock mass, dense structural fracture zones, and the contact zones between various vein rocks and surrounding rocks.The eastern part of North China is a gold metallogenic concentration area in Ch

关 键 词：幔枝构造 地幔热柱 成矿作用 控矿构造 储矿构造 成矿规律 找矿方向 

分 类 号：P542.5[天文地球—构造地质学] P613[天文地球—地质学]