摘要
沂水南小尧金矿产于沂沭断裂带内汞丹山凸起上,赋矿围岩为古元古代花岗岩。对其形成时代及成因,历来争议颇大,主要认为是与前寒武纪变质热液有关的金矿床。本次研究对南小尧金矿矿石中的锆石用LA-ICPMS法进行单颗粒锆石微区U-Pb年龄测定,获得锆石上交点年龄为(2 438±13)Ma和下交点年龄(116±20)Ma。从区域成矿条件分析,上交点年龄是赋矿围岩的形成年龄,结合南小尧金矿石中的钾长石矿物K-Ar年龄(94.3±1.4)Ma,其下交点年龄基本代表了金矿的形成时间,本区金矿的形成时代应在早白垩世中-晚期。
Nanxiaoyao gold deposit in Yishui County ore-bearing country rocks are Paleoproterozoic granite. is located in Gongdanshan uplift in Yishu fault belt. Its There has always been quite controversial to their forming age. In this study, by using LA-ICPMS method and single grain zircon U-Pb dating, it is gained that the upper intercept age of zircon is （2 438±13） Ma and the lower intercept age is （116±20） Ma. From analysis on regional ore-forming condition, it is regarded that the upper intercept age is the forming age of its country rocks. Combining with K-Ar age of （94.3±1.4） Ma of potassic feldspar in Nanxiaoyao gold deposit, it is regarded that the lower intercept age can represent the gold-forming age. The forming time of the gold deposits in this area should be in early to late period of Cretaceous era.
出处
《地质调查与研究》
2009年第1期1-7,共7页
Geological Survey and Research
基金
山东省地质勘查研究项目:山东省沂沭断裂带构造演化与成矿作用研究(20070018)
