松辽盆地北部中、新生代构造运动特征及对砂岩型铀矿的控制作用

Mesozoic,Cenozoic tectonic movements and the control on sandstone-hosted uranium deposit in north Songliao basin

松辽盆地北部历经燕山、喜山两期重要的构造运动。燕山期构造运动较为强烈,是松辽盆地北部一些含油气构造形成的重要时期,同时也是砂岩型铀矿成矿的主要时期。喜山期构造运动在松辽盆地内部表现相对较弱,但对铀矿的形成仍然具有控制、调整改造作用。研究认为松辽盆地北部找矿层位主要为下白垩统泉头组、上白垩统青山口组、姚家组、嫩江组,其次为上白垩统四方台组、渐新统依安组。砂岩型铀矿找矿重点区域为西部斜坡区、古中央隆起带和东北隆起区。西斜坡和东北隆起区以寻找层间氧化带型及古河道砂岩型铀矿为主,中央隆起带应注重由反转构造形成的剥蚀天窗地区。

The north Songliao Basin have experienced two major tectonic movements, i.e. Yanshanian movement and Himalayan tectonic movement. Yanshan tectonic movement is relatively strong during which major oil-bearing basins and contemporary sandstone-hosted uranium deposits formed. Himalayan tectonic movement was relatively weak within the basin but also played role in control, adjustment and reconstruction of formation of uranium deposit. Studies show that uranium ore exploration in the northern basin should target to Early Cretaceous Quantouformation, Late Cretaceous Qingshankou formation, Yaojia formation, Nenjiangformtion, then Late Cretaceous Sifangtai formation, Oligocene Yianformation and to the western slope and paleo-uplifts in central and northeast of the north Songliao basin. In the west slope and northeast uplifts exploration is concentrated on the interformation oxidation zone-hosted uranium deposit and sandstone-hosted uranium deposit occurring in paleo-river beds and in windows in reversed stratigraphic units in the central uplifts.