摘要
文章通过同位素稀释热电离质谱(ID_TIMS)锆石U_Pb法、Rb_Sr等时线法和钾长石40Ar/39Ar测年与MDD模拟得到的数据,分析了阿尔金山北缘地区花岗岩浆活动的主要时期、与阿尔金北缘大平沟金矿有关的花岗岩形成年龄、大平沟金矿可能的成矿时代以及剥露作用时代等问题,探讨了早古生代岩浆活动与金成矿作用之间的关系以及金矿床的剥露历史。Rb_Sr等时线法给出大平沟金矿石英流体包裹体等时线年龄为(487±21)Ma,与阿尔金山早古生代岩浆活动的时代一致,代表了大平沟金矿床的成矿年龄。大平沟金矿的剥露作用发生在早侏罗世拉配泉断裂伸展作用时期。
The relationship between granitic magmatism and gold mineralization and the exhumation history of the Dapinggou gold deposit in northern Altun Mountains of Northwest China are discussed in this paper based on such geochronological data as zircon U_Pb ages, Rb_Sr isochron ages, 40 Ar/ 39 Ar dating and MDD modeling data. The Rb_Sr isochron age 〔(487±21) Ma〕 of 6 quartz inclusion samples from quartz veins in this gold deposit is very close to the age of West Dapinggou granite dated before. According to the age data and the geological setting of this area, the authors conclude that the Dapinggou gold deposit was formed at the early stage of the Early Paleozoic granitic magmatism in northern Altun Mountains and exhumed in Early Jurassic due to the normal faulting of Lapeiquan detachment. The Early Paleozoic magmatism might have provided heat source and produced geological fluid, which was very important for the gold mineralization. The exhumation process in Mesozoic made the gold deposit uplifted to a near_surface position.
出处
《矿床地质》
CAS
CSCD
北大核心
2004年第4期464-472,共9页
Mineral Deposits
基金
国家基础研究发展规划项目(编号2001CB409808和01CB71100103)
国土资源大调查项目(编号K1.1.2.3)的资助
