二连盆地反转构造与砂岩型铀矿成矿作用  

Inversion Structure and Its Relationship with Sandstone Type Uranium Metallization in Erlian Basin

作　　者：刘武生[1] 赵兴齐[1] 康世虎[2] 史清平[1] 张梓楠[1] 

机构地区：[1]核工业北京地质研究院中核集团铀资源勘查与评价技术重点实验室,北京100029 [2]核工业208大队,内蒙古包头014010

出　　处：《铀矿地质》2018年第2期81-89,共9页Uranium Geology

基　　金：中核集团龙腾二期"北方重点盆地砂岩型铀矿资源扩大与靶区优选"项目;中核集团集中研发项目"二连盆地深部层位铀成矿关键地质问题研究与靶区优选"(编号:地LTD1601-1)联合资助

摘　　要：笔者将二连盆地的形成与演化划分为初始断陷(J1-2)与反转期(J3)、强烈断陷(K1a-K1t)与反转期(K1s1)、坳陷(K1s2)与强烈反转期(K2e-E2y)等3个断陷(坳陷)沉积作用与反转作用期的交替演化过程。在不同的反转构造期,其反转类型、反转形态和反转程度不一。研究发现,在反转背斜构造核部、反转鼻状构造及强烈反转单斜构造部位,赛汉组下段主要发育潜水氧化带型铀矿化;而在反转背斜构造的两翼、较强烈和中等程度的反转单斜构造部位,赛汉组上段古河道内发育潜水-层间氧化带型铀矿化;在微弱反转构造区,砂岩型铀矿的成矿作用不发育。据此,通过磷灰石裂变径迹反演和镜质体反射率反演,估算了赛汉晚期以来的剥蚀厚度,查明二连盆地反转构造的强弱分布,提出有利于砂岩型铀矿成矿的区段。In this paper, the formation and involution of Erlian basin was divided into 3 alternative stages： initial faulting（J1-2） and initial inverse（J3） stage, intense faulting（K1 a-K1 t） and inverse（K1 s1） stage, depression（K1 s2）and intense inversion（K2-E2）. The inversion type, shape and intensity are different in different inversion stage. It can be inferred that inversion structure core of anticline, inversion nose structure and intense monocline inversion structure in the lower member of Saihan formation were favor to develop phreatic oxidation sandstone uranium. Inversion structure limbs of anticline, sub-intense and moderate monocline inversion structure were favor to develop phreatic-interlayer oxidation sandstone uranium in paleo-channel of the upper member of Saihan formation. However, poor uranium mineralization were developed in slight inversion structure areas.Therefore, apatite fission track and vitrinite reflectance method were used to estimate the erosion thickness and distribution of inversion structure intensity since Saihan formation in Erlian basin, and favorable mineralization zones for sandstone uranium were proposed.

关 键 词：二连盆地 反转构造 砂岩型铀矿 潜水氧化 层间氧化 

分 类 号：P612[天文地球—矿床学]