陕西省凤太矿集区柴蚂金矿床碳酸盐矿物的Sm-Nd同位素测年及意义  

Sm-Nd isotopic dating of carbonate minerals from the Chaima gold deposit in the Fengxian-Taibai ore concentration area,Shaanxi Province and its implications

作　　者：刘协鲁 王义天[2] 胡乔青[2] 魏然[2] 王瑞廷 温深文 陈明寿 杨光华 

机构地区：[1]中国地质大学地球科学与资源学院,北京100083 [2]中国地质科学院矿产资源研究所,国土资源部成矿作用和资源评价重点实验室 [3]西北有色地质勘查局 [4]西北有色地质勘查局717总队 [5]西安地质矿产勘查开发院

出　　处：《岩石学报》2014年第1期271-280,共10页Acta Petrologica Sinica

基　　金：中国地质调查局地质调查工作项目(1212011220869);国家自然科学基金项目(41372089);国家"十一五"科技支撑计划课题(2006BAB01A11);中央级公益性科研院所基本科研业务费专项资金项目(K0801)联合资助

摘　　要：柴蚂金矿床位于陕西省凤太矿集区西北部,八卦庙超大型金矿床西侧约0.5km处,二者在成矿地质背景和控矿条件等方面均较为相似。该矿床共划分出5个含矿带,其产出位置受地层和构造联合控制。矿石类型有石英脉型和蚀变岩型,以石英脉型为主。成矿过程可划分为早期石英-碳酸盐阶段、主成矿期石英-碳酸盐-硫化物阶段和晚期石英阶段。本次工作对主成矿阶段的白云石、方解石等碳酸盐矿物进行了Sm-Nd同位素测年研究,获得等时线年龄为203.2±1.6Ma,表明矿床形成于晚三叠世。结合前人对区内金矿、岩浆岩和构造活动的研究认为,柴蚂金矿床是印支末期后碰撞过程中形成的造山型金矿床。The Chaima gold deposit is located on the northwest of the Fengtai ore concentration area in Shaanxi Province and 0. 5km west to the super-large Baguamiao gold deposit. They are similar in metallogenic geological environment and ore-control conditions. There are five ore-bearing zones in this deposit and their occurrence is controlled by lithology and tectonic. The ores are quartz-vein type and altered-rock type,in which the first is the main type. The gold mineralization of Chaima gold deposit could be divided into three stages： the early quartz-carbonate stage,the second and main quartz-carbonate-sulfide stage and the late quartz stage. In this paper,the Sm-Nd isotopic dating is carried out on the calcite and dolomite from the main stage,yielding an isochron age of 203. 2 ± 1. 6Ma,which shows that the deposit formed in Late Triassic. Combined with the previous research on the gold deposits,magmatite and tectonic movements of the area,we suggest that the Chaima gold deposit is an orogenic gold deposit formed after the collision of Qinling in Late Indosinian.

关 键 词：Sm-Nd同位素测年 方解石 柴蚂 凤太矿集区 

分 类 号：P597.3[天文地球—地球化学]