中国火山岩型铀矿的主要地质特征  

Principal geological characteristics of the volcanic-type uranium deposits in China

作　　者：方锡珩[1] 

机构地区：[1]核工业北京地质研究院,北京100029

出　　处：《铀矿地质》2009年第2期98-104,共7页Uranium Geology

摘　　要：火山岩型铀矿主要分布于环太平洋的中、新生代多金属成矿带,产于以酸性岩或碱性岩为主的陆相火山岩系中,据对火山岩的87Sr/86Sr含量初始比值测定、火山岩的稀土元素分布模式和火山岩中的熔融包体测温研究,推测火山岩浆是硅铝壳高温大部分熔融的产物,并不同程度受到地幔物质的混染。火山喷发受区域大断裂带控制,形成喷发岩带。火山喷发岩带可进一步划分为几条喷发亚带,喷发亚带则由一系列的火山活动中心组成。火山岩型铀矿均产于断陷红盆旁侧,或在其附近存在基性脉岩群,显示铀矿化与深部构造岩浆活动存在成因联系,适中的剥蚀程度是重要的找矿前提。The volcanic-type uranium deposits in China distribute in two gigantic active belts, that is, circum-Pacific belt and latitudinal structure belt crossing Europe-Asia. The volcanic-type uranium deposits occur in continental volcanics, which are mainly composed of acid or alkali volcanics. Based on the study of ^87 Sr/^88 Sr initial ratio, REE distribution pattern and melt inclusion thermometry of volcanics, it is found that volcanic magma originated mainly from high-temperature melt of sialsphere and they were propably contaiminated partially by mantle materials. The volcanic eruption was controlled by regional fault and formed eruption belt, the beld can be divided into several sub-beh which was comprised by a serial eruption centres. The volcanic-type uranium deposits occur by the side of down-faulted red basin or associated with basic swarm. This means that the uranium mineralization is related to deep tectonics-mag- matism. The paper proposes that the moderate erosion of volcanic belt is an important precondition to find uranium deposits.

关 键 词：火山岩型铀矿床 陆相火山岩带 火山活动中心 断陷红盆 

分 类 号：P619.14[天文地球—矿床学]