文献类型：期刊文献

中文题名：滇东南马卡铅锌钨矿床成因:闪锌矿Rb-Sr、锡石U-Pb定年和硫化物原位硫、铅同位素制约

英文题名：Genesis of the Maka Pb-Zn-W deposit in southeastern Yunnan:Constraints from sphalerite Rb-Sr dating,cassiterite U-Pb dating and in-situ S,Pb isotopes of sulfide

作者：刘明军 杨光树 陈爱兵 温汉捷 燕永锋 杜胜江 李建宽 杨昕宇

第一作者：刘明军

机构：[1]昆明理工大学国土资源工程学院,昆明650093;[2]长安大学地球科学与资源学院,西安710054;[3]贵州理工学院矿业工程学院,贵阳550003

第一机构：昆明理工大学国土资源工程学院,昆明650093

年份：2023

卷号：39

期号：6

起止页码：1861-1879

中文期刊名：岩石学报

外文期刊名：Acta Petrologica Sinica

收录：CSTPCD;;EI(收录号：20233214491360);Scopus;WOS:【SCI-EXPANDED(收录号:WOS:001005970000017)】；北大核心:【北大核心2020】；CSCD:【CSCD2023_2024】；

基金：国家自然科学基金项目(42072094、42162012、41962005)资助。

语种：中文

中文关键词：Rb-Sr同位素;原位S、Pb同位素;矽卡岩;马卡铅锌钨矿床;老君山

外文关键词：Rb-Sr isotope;In situ S,Pb isotopes;Skarn;Maka Pb-Zn-W deposit;Laojunshan

摘要：马卡铅锌钨矿床地处云南省马关县与麻栗坡县的南温河交界处,位于燕山晚期老君山复式花岗岩体北缘。野外地质调查发现,该矿床主要发育矽卡岩型、石英脉型铅锌矿化和萤石石英脉型白钨矿化,但它们的形成机制仍缺乏系统研究。本文通过闪锌矿Rb-Sr、锡石原位U-Pb同位素定年和硫化物原位S、Pb同位素分析,厘定了马卡矿床不同类型铅锌矿化年龄,并探讨了其成矿物质来源及成因机制。矽卡岩型和石英脉型铅锌矿石中闪锌矿分别获得了88.9±1.9Ma(MSWD=4.5)和85.18±0.72Ma(MSWD=1.2)的Rb-Sr等时线年龄,同时获得石英脉型铅锌矿石中锡石LA-ICP-MS U-Pb年龄为84.3±4.7Ma(MSWD=0.66)。结果指示锌、锡矿化时代为晚白垩世,矽卡岩型和石英脉型铅锌矿化分别与该区广泛出露的老君山花岗岩(-90Ma)和花岗斑岩年龄(80-86Ma)一致。矿石硫化物原位硫同位素测试结果显示,δ34S值范围为2.53‰-9.65‰,均值为4.7‰,与老君山花岗岩中硫化物硫同位素组成(4.07‰)相似,表明硫主要来源于老君山花岗岩,少部分源自沉积地层;原位铅同位素组成特征也表明矿石铅主要源自老君山花岗岩。综合研究认为,老君山花岗岩体南北缘地区具有相似的成矿地质条件。马卡矿床的形成主要与燕山晚期老君山复式花岗岩体有关,可能经历了与花岗岩有关的矽卡岩型矿化和与花岗斑岩有关的热液充填、交代成矿过程。
The Maka Pb-Zn-W deposit is located at the northern margin of the Late Yanshanian Laojunshan granite pluton,the junction of Nanwenhe in Maguan County and Malipo County,Yunnan Province.Three different types of mineralization were identified in the Maka deposit,including skarn-type Pb-Zn mineralization,quartz vein-type Pb-Zn mineralization and fluorite-quartz vein-type scheelite mineralization.However,up to now,the mineralization mechanisms and relationships of different types of mineralization are still unclear.This paper reports the Rb-Sr dating and in-situ S,Pb isotopic compositions of sphalerite in different types Pb-Zn orebodies,as well as the in-situ U-Pb dating of cassiterite in quartz vein-type Pb-Zn orebody.The results show that Rb-Sr isochron ages of sphalerite samples from skarn type and quartz vein-type Pb-Zn ores are 88.9±1.9Ma(MSWD=4.5)and 85.18±0.72Ma(MSWD=1.2),respectively.The LA-ICP-MS U-Pb age of cassiterite from the vein-type Pb-Zn ore is 84.3±4.7Ma(MSWD=0.66).These ages indicate that the Pb-Zn(-Sn)mineralization of the Maka deposit were formed in Late Cretaceous,which is highly consistent with the age of widely exposed Laojunshan granite(~90Ma)and granite porphyry(80~86Ma).Theδ34 S values of sulfides from the Pb-Zn ores range from 2.53‰to 9.65‰,with a mean value of 4.7‰,which is similar to the Laojunshan granite porphyry(4.07‰),and lower than the host-strata(17.5‰~25.8‰).The S-Pb isotope data indicate that the ore-forming materials were mainly derived from the Laojunshan granite,with a small amount from the ore-bearing strata.These results suggest that the formation of the Maka deposit is mainly related to the Late Yanshan Laojunshan granitic complex,and the metallogenetic geological conditions in this area are similar to those in the Dulong mining area.The skarn-type Pb-Zn mineralization in the Maka deposit is mainly related to granite,and the quartz vein-type Pb-Zn mineralization is formed by hydrothermal filling and replacement related to granite porphyry.