湘南红旗岭锡多金属矿床地质特征及Ar-Ar同位素年代学研究  

Geological characteristics and 40 Ar-39 Ar geochronology of the Hongqiling tin deposit in southern Hunan Province

作　　者：袁顺达[1] 刘晓菲[2] 王旭东[1] 吴胜华[1,2] 原垭斌[2] 李雪凯[2] 王铁柱[2] 

机构地区：[1]中国地质科学院矿产资源研究所,国土资源部成矿作用与矿产资源评价重点实验室 [2]中国地质大学,北京100083

出　　处：《岩石学报》2012年第12期3787-3797,共11页Acta Petrologica Sinica

基　　金：国家重点基础研究973项目(2012CB416704);中央级公益性科研院所基本业务费专项资金(K1204);国家自然科学基金项目(40903020;41173052);公益性行业基金(200911007-11)联合资助

摘　　要：红旗岭锡多金属矿床是湖南东坡矿田代表性的脉状矿床,亦是湖南省最大的脉状锡矿,并与同一断裂带上相邻的枞树板和南风坳等脉状铅锌银矿构成了一套Sn-W-Pb-Zn-Ag矿床组合。在已有研究的基础上,我们对该矿床进行了高精度白云母Ar-Ar测年,获得坪年龄为153.3±1.0Ma,相应的等时线年龄为153.6±1.5Ma(MSWD=0.55),反等时线年龄为153.5±1.5Ma(MSWD=2.1)。这些年龄数据明显早于相同矿石类型石英流体包裹体的Rb-Sr等时线年龄(143.1±8.7Ma)及相伴产出的花岗斑岩钾长石40Ar-39Ar年龄(144±3Ma),而与千里山岩体主体相锆石SHRIMPU-Pb年龄(155～151Ma)及与之相关的柿竹园矿床(151.0±3.5Ma)和金船塘矿床(158.8±6.6Ma)矽卡岩型矿床的Re-Os等时线年龄在误差范围内相一致,指示区内脉状矿床亦与千里山岩体存在密切的时空关系。综合已有的研究认为,高热花岗岩浆的高分异演化是区内多金属元素巨量堆积成矿的物质基础,不同的围岩性质及构造条件则可能制约了不同的矿化过程,从而形成不同的矿床组合。当围岩为泥盆系碳酸盐岩时,形成一套接触带矽卡岩-云英岩-大理岩型钨锡钼铋铅锌矿和远端脉状铅锌银矿床组合,而当围岩为震旦系碎屑岩时,沿构造通道(断裂带)发育一套脉状钨锡多金属矿和远端脉状铅锌银矿床组合。The Hongqiling tin-polymetallic deposit is a typical lode-type deposit from the Dongpo ore field,which is also the largest lode-type tin deposit in Hunan Province.Both the Hongqiling tin deposit and the adjacent Congshuban and Nanfeng＇ao lead-zinc-silver deposits controlled by the same NE-trending fault zone compose a lode-type Sn-W-Pb-Zn-Ag continuum ore system.In this study,high-precision Ar-Ar dating on muscovite collected from the Hongqiling deposit has been carried out,and yielded a well-defined 40Ar/39Ar plateau age of 153.3±1.0Ma,with an isochron age of 153.6±1.5Ma（MSWD=0.55） and an inverse isochron age of 153.5±1.5Ma（MSWD=2.1）.These new geochronlogical ages are significant older than the Rb-Sr isochron age（143.1±8.7Ma） of fluid inclusions in quartz from the quartz vein-type ore and the K-feldspar 40Ar-39Ar age（144±3Ma） of the granite porphyry,but is consistent with the SHRIMP zircon U-Pb ages（155~151Ma） of the Qianlishan granites,and with the molybdenite Re-Os ages of the Shizhuyuan（151.0±3.5Ma） and the Jinchuantang（158.8±6.6Ma） skarn type ore deposits within error,indicating that the mineralizations of lode-type ore deposits in this area are also spatially and temporally related to the Qianlishan granite pluton.Combining with previous studies,we proposed that highly fractionated and high heat producing（HHP） granitic magma provided mainly ore-forming materials for super-accumulation of multi-metals to form several（super-） giant polymetallic deposits in this area,and different physicochemical properties of wallrock and geological structure conditions controlled the mineralization styles to form different ore deposit system.Skarn-greisen type W-Sn-Mo-Bi-Pb-Zn polymetallic deposits are commonly developed in the contact zone between the Qianlishan granite pluton and the Devonian carbonate country rock,associated with Pb-Zn-Ag vein deposits occurring in distal zone of skarn.While lode-type Sn-W-Pb-Zn-Ag deposits controlled by NE-trending fault zones are mainly hoste

关 键 词：Ar-Ar测年 白云母 红旗岭脉状锡矿 湖南 

分 类 号：P597.3[天文地球—地球化学] P618.44[天文地球—地质学]