地质学报（英文版）2004，Vol.78Issue(2)：515-523,9.
Early Paleozoic Magmatism and Gold Mineralization in the Northern Altun, NW China
Early Paleozoic Magmatism and Gold Mineralization in the Northern Altun, NW China
摘要
Abstract
This paper discusses the relationships between granitic magmatism and gold mineralization and the exhumation history of the Dapinggou gold deposit in northern Altun, NW China based on the geochronological data,including zircon U-Pb ages, Rb-Sr isochron age and 40Ar-39Ar dating and MDD modeling data. The main granitic magmatism age in this area is attained from the ID TIMS U-Pb geochronology of zircons from the Kuoshibulak granite,the biggest granite in the northern Altun area, which gives a concordant age of 443±5 Ma in the Late Ordovician. Zircon ID TIMS U-Pb geochronology of the West Dapinggou biotite granite west of the Dapinggou gold deposit gives concordant ages around 485±10 Ma, representing the early stage of Ordovician magmatism. The Rb-Sr isochron age (487±21 Ma) of 6 quartz inclusion samples from quartz veins in this gold deposit is very close to that of the West Dapinggou granite. MDD modeling of step heating 40Ar- 39Ar data of K-feldspar from the same West Dapinggou biotite granite gives a rapid cooling history from 300℃ to 150℃ during 200-185 Ma. According to the age data and the geological setting of this area, we conclude that the Dapinggou gold deposit was formed at the early stage of the Early Paleozoic granitic magmatism in northern Altun, and exhumed in the Early Jurassic due to the normal faulting of the Lapeiquan detachment. The Early Paleozoic magmatism may provide heat source and produce geological fluids, which are very important for gold mineralization. Exhumation in the Mesozoic caused the uplift of the deposit towards the ground surface.关键词
granite, zircon U-Pb chronology, gold deposit, Rb-Sr chronology, exhumation, 40Ar-39Ar dating and MDD modeling, northern AltunKey words
granite, zircon U-Pb chronology, gold deposit, Rb-Sr chronology, exhumation, 40Ar-39Ar dating and MDD modeling, northern Altun分类
天文与地球科学引用本文复制引用
CHEN Xuanhua,WANG Xiaofeng,George GEHRELS,YANG Yi,QIN Hong ,CHEN Zhengle,YANG Feng,CHEN Bailin ,LI Xuezhi..Early Paleozoic Magmatism and Gold Mineralization in the Northern Altun, NW China[J].地质学报（英文版）,2004,78(2):515-523,9.基金项目
The work is an international co-operation research project supported jointly by the National Fundamental Research and Development Projects (2001CB409808 and 01CB71100103) and the National Resource Investigation Project K1.1.2.3 of China. The Continental D （2001CB409808 and 01CB71100103）
