松辽盆地西缘泰康地区四方台组铀成矿特征

近年来,松辽盆地西缘泰康地区四方台组发现了多处铀矿化点,显示该地区具有砂岩型铀矿找矿潜力.通过结合岩心观察、钻孔取样和室内镜下鉴定等方法,对该地区四方台组沉积相特征和构造活动等铀成矿控制条件进行分析.结果表明四方台组沉积相类型主要为三角洲平原和滨-浅湖相,砂岩具有砂体厚度较薄和含砂率较低的特征;盆地构造活动控制了区内铀矿化异常孔位的发育范围,铀矿化部位大多位于烃类等还原性流体渗出改造后的砂岩中.可见该区铀富集作用主要与深部烃类流体上移浅层位发生还原作用有关,受四方台组所发育沉积相类型控制因素较小.

Analysis on uranium metallogenic characteristics of Sifangtai formation in Taikang area, Western Songliao basin

In recent years, several uranium mineralized occurrences have been found in Sifangtai formation of Taikang area in the western margin of the Songliao Basin, which shows that the area has prospecting potential for sandstone type uranium deposits. The methods of core observation, drill hole sampling and microscopic identification have been applied to analyze the controlling factors of uranium mineralization, such as characteristics of sedimentary facies and tectonic activities of Sifangtai formation in the studying area. The research results show that the delta-plain and shallow lake sedimentary facies are mainly developed in the Sifangtai formation. Sandstone is characterized by limited thickness of sand body and low sand mud ratio. The developmental extent of uranium mineralization hole positions are controlled by the tectonic activities of the Songliao Basin. Most of the uranium mineralization sites are located in the sandstones which are seeped and reformed with the reductive hydrocarbon fluid. It is considered that the uranium enrichment in the study area is mainly related to the reducing action in the shallow layer where the deep hydrocarbon fluid moved up, less controlled by the sedimentary facies characteristics of Sifangtai formation.