河南省桐柏县破山银矿矿床成因探讨.pdf

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1、Vo1．21。NO．4第21卷第4期中国矿业2012年4月CHINAMININGMAGAZINEApr．2012

2、魄酶河南省桐柏县破山银矿矿床成因探讨张贤良，鞠霞(河南省地质矿产勘查开发局第一地质勘查院，河南南阳473003)摘要：河南省桐柏县破山银矿位处秦岭一大别褶皱系，属围山城金银成矿带西段。矿区出露地层主要为中元古界歪头山组(Ptw)及零星分布的新生界第四系(Q)；矿区位处河前庄倾伏背斜西南翼，构造主要表现为北西向展布的层间滑动断裂带，是区内银矿主要容矿构造；矿体呈不规则似层状、脉状产于层间滑动断裂带中。矿石类型有银矿石、

3、银铅锌矿石和铅锌银矿石三种。本文通过对流体包裹体、同位素地球化学的分析研究认为，矿床可能形成形成于小于5kin的浅部环境；成矿流体属于中一温、低盐度、低密度、富CO的K一SO一型流体；成矿(早)中期以变质流体为主，成矿晚期深度变浅，逐渐演化为以大气水为主；成矿时代为燕山晚期。结合对区域成矿背景及控矿条件的分析认为：破山银矿矿床成因类型应属造山型矿床。关键词：层问滑动断裂带；容矿构造；成矿流体；矿床成因类型；造山型矿床中图分类号：P618．5文献标识码：A文章编号：1004—4051(2012)04—0049—07Discussi

4、onondepositgenesisofposhansilverdepositwhichisinTongbaicounty，HenanprovinceZHANGXian-liang，juXia(TheFirstGeologicalExplorationInstituteofHenanprovincialBureauofGeo-explorationandMineralDevelopment，Nanyang473003，China)Abstract：PoshansilverminewhichisinTongbaicountryof

5、HenanprovincesituatedinQinling—Dabiefoldzone，belongstOthewestsectionofWeiShanchengsilverandgoldmetallogeniebelt．Theexposedstra—tuminminingareamainlyisWaiToushangroupofMeso—proterozoic(Pt2w)andSomescatteredQuaterna—ryofCenozoic(Q)；Miningareasituatedinplunginganticline

6、southwestbranchofHeQianzhuang，geo—logicstructuremainlyisslidingfaultzonesbetweenlayerswhichextendtOthenorthwest，andthisstructureisthemainore—containingstructureofsilvermineinthisarea；orebodyappearsinslidingfaultzonesbe—tweenlayerswithirregularquasilaminateorveinedsha

7、pe．Orehasthreetypesthatissilverore，silver—lead—zincoreandlead—zinc—silverore．Throughtheanalysisresearchonfluidinclusionsandisotopegeochemical，thisarticleconsidersthatthedepositformedintheshallowenvironmentwhichislessthan5kmdepth；ore-formingfluidwasK一SOtypefluidwhichw

8、asintermediatetemperate，lowsalinity，lowdensity，richedinCO2；themetallogenic(early)mid-termmainlywasmetamorphicfluid，thedepthbecamelowerinmetallogenicadvancedstageandevolvedintoatmosphericwaterprimarilygradually．MetallogenicepochwasLate-Yanshanperiod．AccordingtOtheanal

9、ysiswithregionalmetallogenicsettingandore—controllingconditions，theauthorconsidersthatthedepositgenetictypeofposhansilverdepositsho