华东地区燕山期花岗质岩浆与成矿作用关系研究

发布时间：2018-02-28 19:49

本文关键词： 成矿作用岩浆活动成矿带燕山期华东地区　出处：《岩石学报》2017年05期 　论文类型：期刊论文

【摘要】：华东地区是我国重要的钨、铜、铁、钼、金、银、铀、铅、锌等多种金属矿产的产业基地。本文系统总结了华东地区钦杭成矿带和武夷山成矿带等重要多金属成矿带的燕山期岩浆活动与成矿作用的时空演化规律,提出燕山期区域成岩成矿作用可划分为早、晚两期四个阶段。(1)燕山早期早阶段(180~165Ma),以I型花岗岩及埃达克质岩石为主,主要分布在钦杭结合带东段以及武夷山成矿带的闽西南坳陷区内,形成一系列斑岩型及矽卡岩型铜铅锌银多金属矿床;其中埃达克质岩是俯冲板块挤压环境下加厚(或拆沉)下地壳重熔的产物;(2)燕山早期晚阶段(165~140Ma),以S型花岗岩以及钨锡、铌钽矿床为主,主要分布于南岭成矿带,另有少量非埃达克质I型花岗岩;(3)燕山晚期早阶段(145~120Ma),为区域由挤压向伸展过渡的构造转换期,在古太平洋板块斜向俯冲所导致的大规模伸展背景下,产生了S型与I-A型花岗岩共生的局面,其中S型火山-侵入杂岩与火山热液型铀铅锌矿床关系密切;在钦杭结合带东段一线出现A型花岗岩以及伴生的钨锡铌钽矿化,其年龄(135~125Ma)略晚于S型火山-侵入杂岩,在武夷山地区岩石类型则以I型为主,并与矽卡岩型以及石英脉型钨锡铁钼矿有关;(4)燕山晚期晚阶段(120~90Ma),在强烈的伸展背景以及俯冲带向洋迁移作用下,成岩成矿事件集中在武夷山以东的沿海地区,以出现晶洞花岗岩、过碱性花岗岩等高温、浅成、高分异花岗岩类为特征,但金属成矿作用则大多与富钾的I型花岗岩类有关,在多个矿集区内形成大量的浅成低温热液型铜金银矿床。钦杭成矿带和武夷成矿带之间的成岩-成矿时空差异性主要受控于古太平洋板块俯冲过程及基底物质组成。
[Abstract]:East China is the important tungsten, copper, iron, molybdenum, gold, silver, uranium, lead, This paper systematically summarizes the temporal and spatial evolution laws of Yanshanian magmatic activity and mineralization of important polymetallic metallogenic belts such as Qinghang metallogenic belt and Wuyishan metallogenic belt in East China. It is suggested that the regional diagenesis and mineralization of Yanshanian period can be divided into four stages, I. e., early Yanshanian early stage and early Yanshanian early stage, which are mainly composed of I-type granite and adakitic rocks. A series of porphyry and skarn copper-lead-zinc-silver polymetallic deposits were formed in the eastern part of Qinghang joint belt and in the southwest Fujian depression of Wuyishan metallogenic belt. Among them, Adakite is the product of thickening (or delamination) of the lower crust remelting in the compressional environment of the subduction plate. (2) the early Yanshanian late stage (1655) 140Maan, mainly composed of S-type granite and tungsten, tin, niobium and tantalum deposits, mainly distributed in the Nanling metallogenic belt. There is also a small amount of non-Adakitic I-type granitoids in the late Yanshanian early stage, I. e., the early Yanshanian stage, which is a tectonic transition period from compressional to extensional, in a large extensional setting caused by the oblique subduction of the paleo-Pacific plate, and there is also a small amount of non-adakitic I-type granitoids. There is a symbiosis between S-type and I-A type granite, in which S-type volcanic-intrusive complex is closely related to volcanic hydrothermal type uranium, lead-zinc deposit, A-type granite and associated tungsten, tin, niobium and tantalum mineralization occur in the eastern part of Qinghang joint belt. The age of 125Ma is slightly later than that of S-type volcano-intrusive complex, and I type is the main rock type in Wuyishan area. And related to skarn type and quartz vein type tungsten, tin, iron and molybdenum deposit, the late Yanshanian late Yanshanian stage is 120 ~ 90 Ma. Under the strong extensional setting and the subduction zone migration to the ocean, the diagenetic and metallogenic events are concentrated in the coastal area east of Wuyi Mountain. It is characterized by the appearance of granites with crystal caverns, peralkalic granites and other high-temperature, epigenetic and high-grade isomorphic granites, but most of the metal-metallogenic processes are related to the K-rich I-type granites. A large number of epithermal copper gold and silver deposits were formed in several ore concentration areas. The diagenesis and metallogenic space-time differences between Qinghang metallogenic belt and Wuyi metallogenic belt are mainly controlled by the subduction process of paleo-Pacific plate and the composition of basement material.
【作者单位】：中国地质调查局南京地质调查中心;
【基金】：中国地质调查局项目(121201102000150009-10、12120113065500)资助
【分类号】：P588.121;P611

【相似文献】