摘要
黄崖口铅锌矿位于白银矿田外围,一直被认为与小铁山铅锌矿成矿特征类似,是白银矿区外围找矿的重点地段之一。通过对黄崖口铅锌矿区与成矿密切相关的变酸性火山岩LA-ICP-MS锆石U-Pb同位素测年,获得铅锌矿赋矿岩系变流纹岩的形成年龄为(507.6±1.8)Ma(MSWD=0.23,Points=23),属于中寒武世。该年龄可代表黄崖口铅锌矿的形成时代,故认为黄崖口铅锌矿形成于中寒武世。结合前人研究成果,白银铜多金属矿形成时代为(467.1±2.2)~(465.0±3.7)Ma,属于中奥陶世,黄崖口铅锌矿的形成时代早于白银铜多金属矿。因此,初步提出白银铜多金属矿田及外围具有多期成矿特征,该认识对白银矿田外围找矿具有重要指示意义。
Huangyakou lead-zinc deposit is located outside Baiyin orefield,being the main prospecting mining areas.Its metallogenic characteristics have long been considered to be similar to that of Xiaotieshan lead-zinc deposit.Through the LA-ICP-MS zircon U-Pb isotope dating of the meta-acid volcanic rocks in Huangyakou lead-zinc deposit,the age of meta-rhyolite is(507.6±1.8)Ma(MSWD=0.23,Points=23),belonging to the Middle Cambrian.This is also the formation age of Huangyakou lead-zinc deposit.On the basis of previous research,it is held that Baiyin copper polymetallic ore is formed in(467.1±2.2)-(465.0±3.7)Ma which belongs to the Middle Ordovician.There for,Huangyakou lead-zinc deposit was formed earlier than Baiyin copper polymetallic ore.It is proposed that Baiyin copper polymetallic orefield and its periphery are multi-stage metallogenic,which has some implications in the prospecting of the Baiyin orefield.
作者
段忠志
何世平
计波
时超
王立轩
魏小燕
DUAN Zhongzhi;HE Shiping;JI Bo;SHI Chao;WANG Lixuan;WEI Xiaoyan(Chincse Academy of Geological Seciences,Beijing 100037,China;China University of Goscience(Beijing),Reijing 100083,China;Xian Center of Greological Survey,China Geological Survey,Xi'an 710054,Shaanxi,China)
出处
《西北地质》
CAS
CSCD
北大核心
2021年第2期30-42,共13页
Northwestern Geology
基金
中国地质调查局“商丹—大柴旦地区区域地质调查”(DD20190069)二级项目下设“甘肃白银一带J48E021008、J48E022009、I48E022010三幅专项地质调查”子项目。
