内蒙古东乌旗1017高地银铅锌矿床地质地球化学特征及成因初探  

Geological and Geochemical Characteristics and Genesis of Silver-Lead-Zinc Deposit at 1017 Highland in Dong Ujimqin Banner,Inner Mongolia

作　　者：贾丽琼[1,2,3] 王治华[1,4] 徐文艺[3] 王梁[1,4] 李翾[5] 常春郊[4] 

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国地质大学地质过程与矿产资源国家重点实验室,北京100083 [3]中国地质科学院矿产资源研究所,国土资源部成矿作用与资源评价重点实验室,北京100037 [4]武警黄金地质研究所,河北廊坊065000 [5]武警黄金第四支队,辽宁辽阳111000

出　　处：《地质与勘探》2014年第3期550-563,共14页Geology and Exploration

基　　金：中国地质调查局矿产资源远景调查评价项目(编号1212011085263;1212011120292)联合资助

摘　　要：对内蒙古东乌珠穆沁旗1017高地银铅锌矿流体包裹体和同位素地球化学进行了研究。流体包裹体研究显示,从成矿早期到主成矿期,流体温度逐渐降低(从303℃~134℃到247℃~121℃),盐度也在逐渐降低(从13.2%~7.2%到13.0%~4.5%),流体密度变化不太大(从0.97 g/cm3~0.81g/cm3到0.99 g/cm3~0.89 g/cm3),流体压力较低(0.33 MPa^8.19MPa),表明该矿床具有浅成、中低温、中低盐度热液成矿特征。激光拉曼光谱分析显示包裹体气液相成分主要为H2O。氢、氧同位素组成表明,成矿流体早期以岩浆水为主,晚期可能有大气降水的参与。硫、铅同位素分析表明,成矿物质来源于深源岩浆与地层的混合。铅同位素也反映出成矿金属主要来源于地幔岩浆作用,并有壳源铅的混染,且与围岩阿钦楚鲁岩体具有相似的特征。基于野外地质观察,H、O、S、Pb同位素及成岩成矿年龄的对比,认为矿床的形成与阿钦楚鲁岩体密切相关,阿钦楚鲁岩体提供了成矿的物质和流体来源。1017高地银铅锌矿床为岩浆热液型脉状矿床。This work focuses on fluid inclusions and isotope geochemistry analysis of the silver-lead-zinc ore deposit at 1017 highland in Dongwuqi, Inner Mongolia. Fluid inclusion analysis indicates that the temperature and salinity of ore-forming fluid decreased gradually( temperature from 303℃ ~ 134℃ to 247℃ ~ 121℃,salinity from 13. 2% ~ 7. 2% to 13. 0% ~ 4. 5%) from the early to the main mineralization stage while the density kept constant basically( 0. 97 g / cm3~ 0. 81g / cm3to 0. 99 g / cm3~ 0. 89 g / cm3) and the ore-forming pressure was low( 0. 33 MPa ~8. 19MPa). It is thus determined that low-and-medium temperature,low-and-medium salinity,and low pressure characterize the deposit. The Laser Raman data of the ore-forming fluid inclusions shows that it is rich in H2O in gas phase and liquid phase. Hydrogen and oxygen isotope analysis suggests that the ore-forming fluid was dominated by magmatic water in the early stage and could be mixed with meteoric water in the late stage. The compositions of sulfur isotope and lead isotope imply that the metallogenic materials of the deposit derived from the deep magma mixing with strata. The composition of lead isotope also shows that the lead of the deposit derived from the mantle magmatism with contaminated crust-source lead,and it is similar to its wall rocks,Aqinchulu granite. Based on the field geological investigation and comparing with hydrogen,oxygen,sulfur,lead isotope and ages of ore-forming and rock-forming,it is concluded that the formation of this deposit has a close relationship with Aqinchulu granite and the intrusion offered the ore-forming fluid and materials. The 1017 highland silver-lead-zinc ore deposit is a magmatic hydrothermal vein type of deposits.

关 键 词：流体包裹体 同位素地球化学 岩浆热液 1017高地 内蒙古 

分 类 号：P618.52[天文地球—矿床学] P618.4[天文地球—地质学]