摘要
冷水沟铜钼金矿床位于南秦岭山阳—柞水矿集区内,是南秦岭晚中生代斑岩-矽卡岩型铜(钼)矿床的代表性矿床之一。冷水沟矿区内除斑岩-矽卡岩型铜钼矿体外,还发育构造蚀变岩型金矿体,但对于铜钼矿化与金矿化之间是否存在成因联系一直存在疑惑。本次通过对斑岩-矽卡岩型铜钼矿体中辉钼矿与构造蚀变岩型金矿体中蚀变钾长石和绢云母分别进行Re-Os和^(40)Ar-^(39)Ar定年,以期能够通过成矿年代学研究来厘定两者之间的成因联系。测试结果显示,斑岩-矽卡岩型铜钼矿体的辉钼矿Re-Os等时线年龄为(147.4±8.4)Ma,构造蚀变岩型金矿体中蚀变钾长石和绢云母^(40)Ar-^(39)Ar年龄约为144 Ma,两者在误差范围内一致,说明铜钼矿体和金矿体均形成于晚侏罗世—早白垩世,是同一成矿作用的产物,并与区域内晚侏罗世—早白垩世岩浆岩具有密切的成因联系。结合区域构造演化特征,本次研究结果显示冷水沟铜钼金矿床形成于晚中生代秦岭造山带构造体制转变的动力学背景。同时,冷水沟地区金矿成矿时代的限定也表明南秦岭地区存在晚侏罗世—早白垩世金矿成矿作用。
Lengshuigou Cu-Mo-Au deposit is located in the Shanyang-Zhashui ore concentration area,and is one of the representative deposits of the Late Mesozoic porphyry-skarn Cu(Mo)deposits in the South Qinling orogenic belt.In addition to the porphyry-skarn Cu-Mo mineralization,structural-altered rock-type Au mineralization in the Lengshuigou deposit is also developed,but there are always doubts about whether there is a genetic connection between Cu-Mo mineralization and Au mineralization.Therefore,Re-Os dating of molybdenite from the porphyry-skarn Cu-Mo mineralization and ^(40)Ar-^(39)Ar dating of altered potassium feldspar and sericite from structural-altered rock-type Au mineralization were carried out,respectively,in order to be able to pass mineralization ages to determine their genetic relationship between the two mineralization types.The results show that the Re-Os isochron age of molybdenite is(147.4±8.4)Ma,the ^(40)Ar-^(39)Ar ages of the altered potassium feldspar and sericite are 144 Ma,and these ages are consistent within the error range.It indicates that the porphyry-skarn Cu-Mo mineralization and structural-altered rock-type Au mineralization were formed in the Late Jurassic-Early Cretaceous,and they are the products of the same mineralization and magmatic events in the South Qinling orogenic belt.Combined with the regional tectonic evolution,the results show that the Lengshuigou Cu-Mo-Au deposit was formed in the background of the tectonic regime transition of the Qinling orogenic belt during the Late Mesozoic.In addition,the metallogenic epoch of Lengshuigou Au mineralization also shows that the Late Jurassic-Early Cretaceous Au mineralization existed in the South Qinling orogenic belt,which has important indicative significance for regional gold exploration.
作者
陈雷
闫臻
刘凯
代军治
郭现轻
聂潇
庞绪勇
Chen Lei;Yan Zhen;Liu Kai;Dai Junzhi;Guo Xianqing;Nie Xiao;Pang Xuyong(Institute of Mineral Resources,Chinese Academy of Geological Sciences/MNR Key Laboratory of Metallogeny and MineralAssessment,Beijing 100037,China;Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China;Shangluo No.713 Party of Northwest Geoexploration Bureau for Nonferrous Metals,Shangluo 726000,Shaanxi,China;Northwest Nonferrous Geology and Mining Group Co.,Ltd.,Xi’an 710054,China;Chinese Academy of Geological Sciences,Beijing 100037,China)
出处
《吉林大学学报（地球科学版）》
CAS
CSCD
北大核心
2023年第3期713-727,共15页
Journal of Jilin University：Earth Science Edition
基金
国家自然科学基金项目(41872092)
中国地质调查局项目(DD20230564,DD20230316)
国家科技支撑计划项目(2011BAB04B05)
