塔里木盆地库车坳陷克拉苏构造带新近系铀成矿条件分析OA

Currently,the Ridarik uranium deposit and multiple uranium anomalies has been identified in the Kuqa depression,indicating its favorable uranium mineralization potential.In Kuqa depression,the Kelasu structural belt is a key structural unit along the northern margin of the Tarim basin.However,previous studies have primarily focused on the Mesozoic tectonics and sedimentary evolution,less research was conducted on uranium-related mineralization in the shallow Neogene system.The Neogene system has now become a critical uranium exploration horizon in the Tarim basin.This study focuses on analyzing the geological conditions and mineralization patterns of the Neogene system in the area,providing a theoretical basis for subsequent uranium exploration.Based on the finished research results,seismic datasat,well logging data from more than 10 wells,previous analytical and testing results were integrated with geological methods to analyze the uranium source conditions,structural features,lithological characteristics,sedimentary formation characteristics,redox conditions,and hydrogeological conditions of this structural belt.The results showed that the Kuqa depression in the Tarim basin was close to the southern Tianshan mountains and possessed abundant uranium sources.The salt-overlying structural layer of the Kelasu structural belt mainly developed large sags and linear fold belts,with thrust faults and slope zones,making it a favorable structural belt for sandstone-type uranium metallogenesis.The Dabei member of the Kuqa formation and the Keshen-Kela member,as well as the large Dabei member of the Kangcun formation,mainly develop brown-grayish mudstone interbedded with gray fine sandstone,suggesting the development of a fan delta depositional system.The fan delta plain and front mudstone-sandstone-mudstone structure were developed,making it a favorable facies belt for sandstone-type uranium deposits.The salt-overlying layer of the Kelasu structural belt developed a complete and stable recharge-runoff-discharge system,providing favorable hydrogeological conditions for uranium metallogenesis in the Kelasu structural belt.The reducing substances mainly originate from deep organic matter,supplemented by the reducing substances in the strata themselves,so the oil and gas fault zones should be the main reduction barriers.There may be a uranium metallogenic model in the study area where interlayer oxidation is followed by oil and gas reduction superimposition,with the main prospecting direction being the deep fault zones of the Kuqa formation in the Dabei member and the Keshen-Kela member.