蒙古国东部查夫‒萨尔希特铅锌多金属矿区含矿岩体岩石地球化学、年代学特征及其地质意义  

Petrogeochemistry,U-Pb Chronology and Geological Significance of Ore-bearing Plutons in the Chav-Salkhit Lead-zinc Polymetallic Ore Region,Eastern Mongolia

作　　者：石传军 张运迎 张帅[1] 范羽 张君伍 张义波[1] 孟祥熙 汲鹏 田雨 SHI Chuanjun;ZHANG Yunying;ZHANG Shuai;FAN Yu;ZHANG Junwu;ZHANG Yibo;MENG Xiangxi;JI Peng;TIAN Yu(Mongolia Zhengyuan Co.,Ltd.,Shandong Bureau of China Metallurgical Geology Bureau,Jinan 250000,Shandong,China;South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,Guangdong,China)

机构地区：[1]中国冶金地质总局山东局蒙古正元有限责任公司,山东济南250000 [2]中国科学院南海海洋研究所,广东广州510301

出　　处：《大地构造与成矿学》2025年第2期418-436,I0021-I0023,共22页Geotectonica et Metallogenia

基　　金：中国冶金地质总局山东局科学研究项目(SDYJ-KY202008)资助。

摘　　要：为探讨蒙古国东部查夫‒萨尔希特铅锌多金属矿区含矿岩体形成的地球动力学背景,本文选取查夫、萨尔希特和曼顿三处铅锌多金属矿床的含矿岩体开展锆石U-Pb年代学和元素地球化学研究。年代学结果显示,查夫铅锌矿床含矿辉长闪长岩的年龄为195.6±1.5 Ma(早侏罗世),萨尔希特和曼顿铅锌银多金属矿床含矿花岗闪长岩的年龄分别为262.3±1.8 Ma~256.8±1.5 Ma和253.2±1.7 Ma(中‒晚二叠世),形成时代早于其成矿年龄,因此含矿岩体主要作为矿体的含矿围岩。地球化学特征显示,查夫、萨尔希特、曼顿等岩体均属于钙碱性系列侵入岩,岩石富钙、碱,富集轻稀土元素和大离子亲石元素(Rb、K),亏损高场强元素(Nb、Ta),弱Eu负异常。此外,所有中酸性岩石富含角闪石,属于I型花岗岩类。地球化学特征表明这些中酸性岩浆主要起源于下地壳重熔,成岩作用发生于蒙古‒鄂霍茨克板块南向俯冲的活动大陆边缘火山弧环境。To investigate the geodynamic processes of ore-bearing plutons in the Chav-Salkhit lead-zinc polymetallic metallogenic district,zircon U-Pb dating and geochemical analyses were carried out on ore-bearing plutons in the Chav,Salkhit,and Manton deposits.Our results indicate that the ore-bearing gabbro-diorite in the Chav lead-zinc deposit was crystallized at 195.6±1.5 Ma(the Early Jurassic),while the ore-bearing granodiorites in the Salkhit and Manton lead-zinc-silver polymetallic deposits were crystallized at 256.8±1.5 Ma to 262.3±1.8 Ma and 253.2±1.7 Ma(the Middle to Late Permian).The obtained formation ages are consistently younger than the previously reported mineralization ages,indicating that the ore-bearing plutons represent the ore-hosting wall rocks.Geochemical analyses revealed that the Chav,Salkhit,and Manton plutons are characterized by:(1)belonging to the calc-alkaline series;(2)being enriched in calcium,alkali,light rare earth elements,and large ion lithophile elements(Rb,K);(3)being depleted in high field strength elements(Nb and Ta);(4)exhibiting weak Eu negative anomalies.Furthermore,all intermediate-acidic rocks contained abundant amphibole and were classified as I-type granites.These geochemical features suggest that the intermediate-acidic magmas were predominantly derived from lower crustal melting in response to southward subduction of the Mongolia-Okhotsk plate beneath the active continental margin.

关 键 词：蒙古‒鄂霍茨克构造带 查夫‒萨尔希特矿区 含矿岩体 锆石U-PB年代学 

分 类 号：P595[天文地球—地球化学]