摘要
Abstract
Subvolcanic rocks outcropped around the basin margin in northern Xiangshan ore field are mostly in irregular band and zonal structure.The intrusion is mainly occurred in the Late phase of Yans-han,that is the late stage of twice volcanic-eruptive cycle.The three subvolcanic belts are roughly paral-lel to each other which were controlled by fault and volcanic structures and occurred as dike,apophysis, sill and lacolith in the shape of elongate zone and semi-ring.The main rock types of subvolcanic rocks are porphyritic granite and granite porphyry which belong to S-type granites in genesis.Study on chemical composition shew that the rock is low in SiO 2 ,P2 O 5 ,Na2 O,MgO,MnO and Al2 O 3 content and high in TiO 2 ,FeO,Fe2 O 3 ,CaO,K2 O content.Uranium mineralization and subvolcanic rocks is closely re-lated in space ,time and genesis.The forming mechanism is that subvolcanic magma with the minerali-zation fluid rose from deep to shallow and formed volcanic in the end of eruption while the ore-forming fluid continued to move up along the volcanic edifice and faulted structure,and uranium was enriched and deposited by extracting,diffusing and metasomatism.关键词
相山火山盆地/次火山岩/铀成矿Key words
Xiangshan volcanic basin/subvolcanic rocks/uranium mineralization分类
天文与地球科学
