Application Of Seismic Exploration In Sandstone-type Uranium Deposit In Anle Sag,Songliao Basin

In Songliao basin,The breakthroughs in uranium exploration are mainly concentrated in the southwest,especially in Qianjiadian sag and Dalin sag.But in the east of Jiamatu bulge,the research level is relatively low in Anle sag.Geological information show that Anle sag is similar to Qianjiadian sag in uranium source conditions,sedimentary environment and fault structure,and has good uranium metallogenic potential.Based on the comprehensive analysis of geological information and using seismic exploration technology,this paper analyzes the uranium metallogenic conditions through the research of Stratigraphic division,fracture identification,sand body delineation and sedimentary facies analysis,and draws the following conclusions.1)Characteristics of Yaojia formationYaojia formation is widely distributed in the research area.From southwest to northeast,the thickness of stratum is increased from 150m to 800m;the roof of Yaojia formation is distributed in wide and gentle sheet shape from southwest to northeast,shallow in southwest and deep in Northeast,and the buried depth is between 250m and1250m;the floor of Yaojia formation is affected by the basement,and the fluctuation of the floor is complex,and the buried depth is between 400m and 2000m.In the central of the research area,braided fluvial sand body is developed in Yaojia formation.The sand body is thickness,and it has the structure of mud sand interbedding which provides a good storage space for uranium mineralization.2)Structural featuresThrough the comparative analysis of the characteristics of in phase axis,the fault distinguishing marks are established,such as dislocation,number mutation,bifurcation distortion,shape mutation,reflection disorder and the appearance of abnormal waves.,shape mutation or reflection disorder,the occurrence of reflection disorder and abnormal wave.Ten normal faults were interpreted.Among them,fault F₁?F₆ was formed in the early Late Cretaceous and lasted for a long time,which was a large fault cutting through the basement in the research area.Fault F₂,F₃ and F₅ were basin controlling faults,which controlled the distribution of basement.Fault F₇?F₁₀ was small faults formed in Nenjiang period,which affected the sedimentary thickness of Yaojia formation and Nenjiang Formation locally.Many groups of faults provide channels for deep reducing fluid,so the uranium metallogenic environment is superior.3)Characteristics of sedimentary faciesAccording to the characteristics of seismic facies,the sedimentary facies of K₂y¹ are divided.The river bed subfacies are mainly distributed in the middle of the research area,and can be further divided into core beach microfacies and edge beach microfacies according to the characteristics of seismic facies.The core beach microfacies are generally distributed in north-south and north-north-east directions.According to the characteristics of seismic wave group,three main channels can be delineated.Among them,the main channel in the east of F₂ fault is the most widely developed,about 10 km at the widest;thick sand body is developed in some parts of the beach microfacies,with interbedded structure of mud and sand,which can be used as secondary prospecting horizon in the research area for exploration.