松辽盆地中-新生代构造-沉积演化及其对铀成矿地控制作用OACSTPCD

Songliao Basin is a large fault-depression composite sedimentary basin.The composite evolution and filling produced the favorable geological background and metallogenic conditions for uranium mineralization.The structure-filling characteristics of the basin was studied to deepen the understanding of uranium metallogenic mechanism.Based on the study of the structure-filling characteristics of Songliao Basin,this paper summarized the basin-forming dynamics,preliminarily recovered the shapes and features of prototype basin,and identified the structural-sedimentary evolution characteristics and cover types.The study result showed that the basin mainly experienced two stages of basin formation,the Early Cretaceous rift(fault-depression)and the Late Cretaceous depression,resulted in the formation of filling structure of the lower fault and the upper depression,and three sets of favorable formations of upper red and lower black vertically.The Meso-Cenozoic evolution of the basin can be divided into six stages,in which the Paleocene-Eocene(E1-E2)basin developed uplift and denudation under the background of compression,and the deep ore-forming fluid was exuded and reworked on the mineralization with large scale and compromised the main ore-forming period of the basin.