内蒙古十二吐火山盆地铀矿化特征及成矿预测OA

Shiertu volcanic basin is located at the southern end of Zhalantun volcanic rock-type uranium mineralization prospective belt in Inner Mongolia.It is confined by the regional NE-trending Huanggangliang-Ulanhot fault and the NW-trending Xilamulun river fault.Mesozoic volcanic eruptions were intense and frequent,providing favorable conditions for uranium mineralization.To analyze the uranium metallogenic conditions and predict prospective metallogenic areas,this paper summarized the uranium mineralization characteristics and analyzed the ore-controlling factors by integrating field geological survey,remote sensing interpretation,and airborne radiometric survey data,as well as drilling and trenching data.The research results show that uranium mineralization in Shiertu volcanic basin mainly occurs along NE-trending FS1 fault and NW-trending FS6 fault,and is often found near secondary NE-trending and NW-trending cover faults,volcanic structures,and subvolcanic dykes,or at their intersections and superimpositions.The host rocks are mainly the rhyolite,rhyolitic welded tuff,and acidic subvolcanic rocks of Manketouebo Formation.A comprehensive analysis suggests that uranium mineralization is mainly controlled by a combination of factors such as faults,acidic volcanic rocks,subvolcanic rocks,volcanic structures,and hydrothermal alteration.Uranium mineralization is closely related to hematitization,fluoritization,silicification,and illitization.The uranium mineralization in Shiertu volcanic basin falls into the medium-low temperature hydrothermal type and can be classified into three subtypes based on the occurring location:altered fracture zones,subvolcanic rocks,and interlayered fracture zones.Based on the summarized ore-controlling factors and exploration indicators,one exploration target area and two prospective mineralization areas were predicted for the next exploration.