湘东南燕山早期钨锡与铅锌多金属矿床组合形成的构造-岩浆动力学机制  

Tectonic-Magmatic Mechanisms of the Two Types of Early Yanshanian W-Sn-Polymetallic and Pb-Zn-Polymetallic Deposit Assemblages in Southeast Hunan

作　　者：柏道远[1] 周亮 王先辉 张晓阳 马铁球 

机构地区：[1]中国地质大学,武汉430074 [2]湖南地质研究院,湘潭411100

出　　处：《地质学报》2007年第9期1238-1247,共10页Acta Geologica Sinica

基　　金：中国地质调查局区域地质调查项目(编号200213000035);湖南省地质勘查局"湘东南中生代构造演化与成矿"项目资助的成果

摘　　要：湘东南地区燕山早期与花岗岩体相关的矿床总体可分为中高温的钨锡多金属和中低温的铅锌多金属两类矿床组合。结合岩石大地构造学研究成果和区域构造演化背景,分别对两类矿床组合的温度条件以及矿床、构造、岩浆岩之间的相关性产生的原因进行分析,提出两类矿床组合形成的构造-岩浆动力学机制:①茶郴断裂南东隆起区和断裂北西拗陷区内的局部隆起地带岩石圈厚度较大,由于更强烈的岩石圈拆沉引发更大规模的岩浆活动,形成规模较大的中深成岩体,提供长时间高温条件,造成W、Sn等亲花岗岩元素的高程度、大规模富集,从而导致中高温的钨锡多金属矿床的形成。②茶郴断裂北西拗陷区因岩石圈较薄,岩石圈拆沉及其引起的热扰动作用较弱,产生小规模岩浆活动,因而缺乏W、Sn等元素的大规模富集,而Pb、Zn、Cu等元素则源源不断地运移到地表,加之缺乏长时间高温条件,导致大规模的中低温铅锌多金属矿床的形成,而中高温的钨锡多金属矿床缺乏。上述不同构造背景下的岩浆-成矿过程的差异,导致湘东南钨锡多金属和铅锌多金属两类矿床组合的形成。The deposits related to Early Yanshanian granitic bodies in southeast Hunan can be divided into two types of deposit assemblages, namely mid-high temperature W-Sn-polymetallic deposit assemblages and mid-low temperature Pb-Zn-polymetallic deposit assemblages.Combining with petrological-geotectonica achievements and tectonic evolution setting, the authors studied the temperature situations, and the correlation among deposit, tectonic and magmatic rocks, finally put forward tectonic-magmatic mechanisms of the two types of deposit assemblages.①In the upwelling region to the east of the Chaling-Chenzhou fault and the local upwelling places of the down-warping region to the west of the fault, the lithosphere was thicker, violenter lithospheric delamination caused larger-scale magmatisms, and large mid-deep plutons formed. These processes made incompatible elements such as W and Sn, etc. concentrate highly in large scale, and provided long time high temperature condition, which caused the mid-high temperature W-Sn-polymetallic deposits. ②In the down-warping region to the west of the Chaling-Chenzhou fault, the lithosphere was thinner, lithospheric delamination and thermal activities are weaker, and magmatisms scale was smaller, which caused the lack of large-scale richness of W and Sn, etc., and Pb, Zn and Cu etc. moved to near the earth＇s surface. These processes and the lack of continuous high temperature condition caused the froming of large-scale mid-low temperature Pb-Zn-polymetallic deposits and the lack of mid-high temperature W-Sn-polymetallic deposits. Above different magmatic-metallogenetic processes in different tectonic settings caused the forming of the two types of W-Sn-polymetallic and Pb-Zn-polymetallic deposit assemblage.

关 键 词：燕山早期 钨锡多金属矿床 铅锌多金属矿床 构造-岩浆动力学机制 湘东南 

分 类 号：P618.4[天文地球—矿床学]