沂水南小尧金矿锆石U-Pb同位素特征及其地质意义

U-Pb Isotopic Geo-chronological Characteristics and Implications of Zircon in Nanxiaoyao Gold Deposit in Yishui

摘要:

沂水南小尧金矿产于沂沭断裂带汞丹山凸起上，赋矿围岩为古元古代花岗岩。通过对南小尧金矿矿石中的锆石采用LA-CPMS法进行单颗粒锆石微区U-Pb同位素年龄测定，获得锆石谐和年龄（2438±13）Ma的结果，为赋矿围岩的形成年龄；而下交点（116±20）Ma大致为金矿的形成年龄。结合南小尧金矿石中钾长石矿物K-Ar年龄为（94.29±1.38）Ma的结果分析，本区金矿的形成时代应在早白垩世中晚期。

Abstract:

Nanxiaoyao gold deposit in Yishui county locates in Gongdanshan uplift in Yishu fault belt. Its ore-bearing country rocks are Paleoproterozoic granite. There has always been many controversy to their forming age. In this study, by using LA-CPMS method an