Geochronology,geochemical characteristics and tectonic setting of the Yunfeng rock mass in Jilin Province
The Yunfeng rock mass is located in the Yalu River fault metallogenic belt of important non-fer-rous metal and precious metal,eastern part of Jilin Province.The petrology,geochemistry,geochronology,and zircon U-Pb dating of the Yunfeng pluton are studied.The main lithology is K-feldspar granite.LA-ICP-MS zircon U-Pb dating of the rock,concordant age of(120.9+1.8)Ma,indicates that the rock mass was formed in Early Cretaceous(later than the activity time of the Yalu River fault).The Yunfeng K-feldspar granite is rich in SiO2,K2O,poor in Al2O3,enriched in Rb and other large ion lithophile elements,depleted in P,Ti,Sr and other elements,depleted in heavy rare earth elements,and obviously depleted in Eu,which belongs to typical non-orogenic A-type granite.The magma source is shallow and dominated by crust-derived materials,indicating that the strata may be affected by the collision of the Pacific plate subducting westward to the Eurasian plate,with a strong collision extensional tectonic background.The tectonic process of crustal extension-thinning occurs locally near the fault zone,and the magma rises and condenses along the formed fault channel.
A-type granitezircon U-Pb ageearly CretaceousYalu River faultYunfeng rock massJilin
万方数据
维普
