浅析松辽盆地南部宝林地区姚家组下段多层铀矿化主要控矿因素

Analysis on Main Controlling Factors of Multilayer Uranium Mineralization in Lower Yao-jia Formation in Baolin Area,Southern Songliao Basin

松辽盆地南部宝林地区的工业铀矿化主要产于上白垩统姚家组下段中,铀矿化受层间氧化作用明显,具有多层氧化带与灰色砂体相间产出的特点,部分钻孔中可见多层工业铀矿化,研究认为,区内铀成矿的主要控矿因素是层位、砂体和物理化学界面,其中姚家组下段第一亚层、第二亚层是宝林地区主要找矿目标层,各亚层的隔水层及砂体控制了区内层间氧化带的发育,氧化带与灰色砂体的物理化学边界控制了矿体定位,第一亚层铀矿化具有“上、下氧化,中间成矿”的特点,第二亚层铀矿化具有“多层氧化、多层灰色砂体、多层铀矿化”的特点。

The industrial uranium mineralization in the Baolin area of the southern part of the Songliao Basin mainly occurs in the lower sec-tion of the Yaojia Formation of Upper Cretaceous.Uranium mineralization is obviously controlled by interlayer oxidation,and multi-layer oxidation zone and gray sand body develop alternately.Multi-layer industrial uranium mineralization can also be observed in some boreholes.The study eluci-dates that the main factors controlling the formation of uranium mineralization in the area are horizon,sand body and physico-chemical interface,and the first and second sub-layers of the lower section of the Yaojia Formation are the favorable prospecting targets in the Baolin area.The water-repel-lent layer and sand body of each sublayer control the development of interlayer oxidation zone in the area,and the physicochemical boundary between oxidation zone and gray sand body can be regard as a tool of locating orebody.The uranium mineralization of the first sublayer is characterized by“upper and lower oxidation and intermediate mineralization”,while the uranium mineralization of the second sublayer is characterized by“multi-lay-er oxidation and gray sand body with multi-layer uranium mineralization”.