构造对松辽盆地北部林甸—富裕地区四方台组砂岩型铀成矿的控制作用OA

In recent years,new progress has been made in the exploration for sandstone-type uranium deposits in Lindian-Fuyu area of northern Songliao Basin.A lot of uranium mineralization occurrences have been discovered in the target layer of Sifangtai Formation,indicating promising exploration potential.Therefore,studying the relationship between tectonic evolution and uranium mineralization holds significant practical importance for guiding regional mineral exploration.Based on a comparative analysis of borehole profiles,seismic sections,geophysical logging data,and the regional tectonic evolutionary history.This study proposed that Meso-Cenozoic tectonic-sedimentary evolution of northern Songliao Basin experienced five stages:rift faulting,thermal subsidence depression,compressional uplift,uplift and denudation,and differential subsidence.During Late Jurassic,influenced by the rapid northwest-subduction of Izanagi Plate,early intruded granitic bodies underwent rapid uplift,providing the provenance for uranium-rich sedimentary formations in the basin.From the end of Nenjiang Formation to the end of Sifangtai Formation,tectonic inversion controlled the development and distribution of sedimentary facies within the target horizon.Fluvial sedimentation occurred along early low-lying areas such as Yi'an and Wuyuer depressions,forming north-south trending lenticular sand bodies,which later served as migration pathways and depositional spaces for oxidizing fluids and uranium mineralization.From the end of Mingshui Formation to the end of Paleogene,structural activity controlled the formation of denudation windows and the location/direction of post-genetic ore-forming fluid processes,while also playing a positive role in enhancing the reducing capacity of the sand bodies.Mineralization mainly occurred during this period.Since Oligocene,differential subsidence of the basin and oil-gas exudation along faults have played a role in preserving the sandstone-type uranium deposits.Considering the uranium source,lithology-lithofacies,and post-genetic alteration characteristics of the study area,it is concluded that this area possesses significant metallogenic potential.