小兴安岭北东段火山岩型铀成矿地质条件及找矿方向

Metallogenic condition and prospecting orientation of volcanic-type uranium deposits in the northeast district of Xiaoxing'anling Mountains

小兴安岭北东段地处环太平洋成矿域与古亚洲成矿域叠合区,经历了中新生代以来的火山-岩浆作用,是火山热液型铀矿床的有利产出部位。通过分析小兴安岭北东段地质背景、成矿地质条件,对比俄罗斯卡缅努什火山机构拉斯托契卡矿床,提出NE、NW向和SN向的贯通性基底断裂,以及晚中生代火山塌陷盆地和潜火山岩浆活动中心为该区铀成矿有利地段。铀矿化受溢流相霏细岩、流纹岩、流纹斑岩,以及喷发相凝灰岩,火山侵入相霏细斑岩、花岗斑岩、闪长斑岩和闪长玢岩控制。本区的南峦、宁远村、汤源和翠峦等火山塌陷盆地是铀成矿最有远景的盆地。

Located in the overlapping area of Circum-Pacific and Palaeo-Asia metallogenic domain,northeast district of Xiaoxing＇anling Mountains has been effected by Meso-Cenozoic volcano-magmatism,and is believed to be the favorable region of volcanic hydrothermal type uranium deposits.Based on the analysis of geological background,metallogenic condition and the comparison study on Lasituoqika deposit in Kamiannushi volcanic structure of Russia,it is concluded that the overlapped areas of NE,NW and SN striking basement faults,volcanic collapse basin of Late Mesozoic and the center of subvolcanic magmatism are the favorable regions of uranium mineralization.The mineralization is controlled by effusive felsite,rhyolite,rhyolite porphyry,eruptive tuff and intrusive felsite porphyry,granite-porphyry and diorite porphyry.The volcanic collapse basins of Nanluan,Ningyuancun,Tangyuan and Cuiluan are the most propecting areas in this region.