The controlling effect of Cenozoic tectonic evolution on the mineralization of sandstone-type uranium deposits in the Songliao Basin: evidence from apatite fission tracks

This paper undertakes a systematic study of 13 samples from 4 boreholes in the northern Songliao Basin by conducting apatite fission track tests. The study shows that the Cenozoic tectonic evolution of the Songliao Basin has a controlling effect on the sandstone-type uranium deposits. According to the thirteen AFT tests, the northern area of the Songliao Basin experienced three major rapid tectonic uplifts since late Cretaceous: 1) from the Late Cretaceous to Eocene (71~48 Ma), the whole northern basin experienced a major uplift at an average rate of 8~56 m/Ma; 2) From the Early Oligocene to Miocene (36~18 Ma), the northern basin underwent a differential uplift at an average rate of 24~49 m/Ma, the second uplift showed slightly lower intensity and was of shorter duration than the first one; 3) since Miocene (18~0 Ma), there was a weak tectonic and a slow uplift at an average of 2~19 m/Ma. The three tectonic uplifts were closely related to the subduction rate and moving direction of the Pacific plate. Based on the data from previous low temperature thermal chronology study as well as the research on the metallochronology of the Qianjiadian sandstone-type uranium deposit in the southern Songliao Basin, the tectonic uplifts since Cenozoic were accompanied by subsequent formation of sandstone-type uranium deposits. This indicates that the sandstone-type uranium mineralization is closely related to Cenozoic tectonic evolution, particularly to the tectonic uplift in the late Miocene, and the mineralization process continues to the present. © 2020, Science Press. All right reserved.