沽源-红山子地区中生代火山作用与铀成矿关系

摘要

Based on the time of Mesozoic volcanism, the characteristic of major and trace element, and REE pattern of the volcanic rocks in Guyuan-Hongshanzi area, The Mesozoic volcanism can be divided into the early cycle and later cycle during the Early Cretaceous, and it's magma series is classified in two sub-series, one is alkaline series of trachyte dominated and another is subalkaline series of rhyolite dominated. The relations between Mesozoic volcanism and uranium mineralization is mainly shown in four aspects: (1) Uranium mineralization controlled by the coexist of two magma series; ( 2) Uranium mineralization controlled by superhypabyssal porphyry body in later cycle volcanism during the Early Cretaceous; (3) The porphyry body close to uranium mineralization, bearing the genesis characteristics of crust-mantle action; and (4) High Si and K content in the chemical composition of the mineralization volcanic rocks.%根据沽源-红山子地段中生代火山作用的时间，火山岩的主量元素、微量元素、稀土元素构成等特点，笔者将区内火山活动划分为早白垩世早期和早白垩世晚期两个旋回，将火山岩划分为以粗面质岩石为主的碱性系列和以流纹质岩石为主的亚碱性系列。本区中生代岩浆作用与铀成矿的关系主要表现在：(1)铀成矿受多岩浆系列共存地段控制；(2)铀成矿受晚期岩浆旋回的超浅成酸性斑岩体控制；(3)与铀成矿密切的斑岩体表现为壳幔作用的成因特点；(4)成矿火山岩表现出高硅和高钾的化学成分特点。