陕甘宁盆地北部下白垩统潜水氧化带型铀矿成矿远景研究

A Study on Uranium Metallogenetic Propects of Ground Water Oxidation Zone Type in the Lower Cretaceous,North Shanganning Basin

陕甘宁盆地的北部下白垩统出露相当广泛。下白垩统沉积之后 ,伴随有大面积的垂直隆升。根据沉积地层的岩性岩相特征、新构造运动的表现形式 ,可以区分出K2 -E2 以及N1 -现代两个主要的氧化剥蚀作用期。在这两个氧化剥蚀作用期间 ,产生了大规模的面状氧化作用。有意思的是根据石油钻孔的γ测井资料和实地调研证实 :这种氧化作用所形成的潜水氧化带都与铀矿化有关。同时 ,现代陕甘宁盆地北部所呈现出的高原型自流水盆地的水动力特征 ,暗示出在陕甘宁盆地的北部下白垩统中浅部层位 (一般 >2 0 0m)中的铀矿化以潜水氧化带型为主。

Lower Cretaceous is developped well in the north part of Shanganningbasin. The area was widly uplifting vertically after their deposited .Based on the features of lithology, lithophase and Neotectonic forms, twomain periods of oxdation\|erosion of K2\|E1 and N1\|present can be distinguished. During these two periods, large scale horizontal oxidationwere occured. It is significant that the groud watre oxidation related tothe uranium minerlization and has be proved by the field investigation andthe data of γ\|logging in drillhole for oil. Meanwhile, according to thehydrodynmic fetures of present Shanganning plateau type artesian basin ,itseems that uranium minerlization main related to the ground water oxidationin the upper parts of the Lower Cretaceous.