大兴安岭地区铅锌多金属矿床时空分布、地质特征及成因  

Geology and Genesis of Lead-Zinc Polymetallic Deposits in the Great Xing’an Range

作　　者：吕新彪[1,2] 杨俊声 范谢均 魏巍[1] 梅微[1] 阮班晓[1] 王祥东[2,3] 衮民汕 LüXinbiao;Yang Junsheng;Fan Xiejun;Wei Wei;Mei Wei;Ruan Banxiao;Wang Xiangdong;Gun Minshan(Institute of Geological Survey,China University of Geosciences,Wuhan 430074,China;School of Earth Resources,China University of Geosciences,Wuhan 430074,China;Wuhan Center of Geological Survey CGS,Wuhan 430205,China;Guizhou Non-Ferrous Metals and Nuclear Industry Geological Exploration Bureau,Guiyang 550005,China)

机构地区：[1]中国地质大学地质调查研究院,湖北武汉430074 [2]中国地质大学资源学院,湖北武汉430074 [3]中国地质调查局武汉地质调查中心,湖北武汉430205 [4]贵州省有色金属和核工业地质勘查局,贵州贵阳550005

出　　处：《地球科学》2020年第12期4399-4427,共29页Earth Science

基　　金：内蒙古地勘基金项目(Nos.NMKD2014-23,NMKD2010-3)。

摘　　要：随着近年来找矿工作的不断突破,大兴安岭地区的铅锌多金属矿床在矿化元素组合、矿床时空分布、成因类型等方面逐渐显示出复杂性和多样性特征.为了进一步探究该地区铅锌多金属矿床的差异性及其内在因素,在前期对白音诺尔、拜仁达坝、维拉斯托、浩布高和边家大院等铅锌多金属矿床研究基础上,结合区内前人对中型以上铅锌多金属矿床的资料和成果,重点讨论了区域上中生代与岩浆作用有关的铅锌多金属矿床成矿背景、共性特征和成矿时空规律,获得了以下主要认识:(1)大部分矿床空间上大致以北、中、南近平行的三条NE向矿带展布,其中一南带矿床尤为密集;(2)时间上可分为中-晚三叠世与晚侏罗-早白垩世两期,且后者的矿床数量占大多数,多期次成矿的现象较为普遍;(3)成因类型上,北矿带主要为浅成低温热液型矿床,中、南成矿带则以矽卡岩型和岩浆热液脉型最为重要;(4)在晚侏罗-早白垩世区域范围内的拉伸环境下,大规模的中酸性岩浆侵入活动是大兴安岭地区最重要岩浆-热事件,形成了多种类型的铅锌多金属矿床,其中的高分异花岗岩与南带富锡铅锌多金属成矿的关系密切;(5)F、Mn元素相关的蚀变与矿化具有较为强烈的空间联系;(6)S同位素显示北带矿床的S来源主要为相关的火山-次火山岩,中带矿床S主要来自成矿岩浆,而南带矿床除岩浆外,围岩地层对S也有一定贡献;(7)Pb同位素数据显示其主要为造山带混合铅来源,与晚侏罗-早白垩世时期大兴安岭地区后造山伸展构造环境有关;(8)H-O同位素数据表明区域矿床的成矿流体来源较为相似,浅成低温热液型矿床流体中大气降水比重较大,而矽卡岩型和岩浆热液脉型矿床则主要为岩浆水,大气降水则在成矿晚期加入.As breakthrough achieved in recent exploration, lead-zinc polymetallic deposits in the Great Xing’an Range have shown complexity and differences in aspects of mineralized elements, temporal-spatial distribution, genesis and so on. For a further inspection of the variation and its internal causes, data from medium-large sized deposits are compiled and compared in this study.Main conclusions are summarized:(1) these deposits formed three parallel NE trending belts with a higher intensity in the southern belt;(2) two major phases of mineralization are recognized as in the Middle-Late Triassic(less important) and the predominant Late Jurassic-Early Cretaceous, superimposed mineralization is also notable;(3) epithermal deposit is representative in the northern belt, while skarn-and magmatic hydrothermal vein-types are more common in the middle and the southern belts;(4) under the Late Jurassic-Early Cretaceous extensional environment, enormous acidic-intermediate magma emplacement affected the whole Great Xing’an Range, leading to the formation of various lead-zinc polymetallic deposits, among which tin-rich ones in the southern belt exhibit genetic links to highly differentiated magma;(5) strong spatial association between the fluorine-, manganese-related alteration and mineralization is noticed;(6) deposits in the northern, middle and southern belts have their sulfur sourced from genetically related volcanic-subvolcanic rocks, ore-related magma and a combination of magma and country rocks;(7) Pb isotope data indicate that most deposits have a mixed lead source from orogeny, probably due to similar regional post-orogenic background in the Late Jurassic-Early Cretaceous;(8) as suggested by H-O isotopic data, meteoric water contributes more for fluid source in epithermal deposits, despite a more crucial role of magmatic water in skarn-and magmatic hydrothermal vein-type deposits.

关 键 词：大兴安岭成矿带 铅锌多金属矿床 燕山期成矿 矿床成因 成矿模式 

分 类 号：P611[天文地球—矿床学]