鄂尔多斯盆地西缘惠安堡地区构造地质及铀成矿特征

Structural Geology and Mineralization of Uranium Deposits in the Huianpu Area,West of Ordos Basin

文章论述了鄂尔多斯盆地西缘大地构造背景、盆地构造单元的划分,以及西缘褶断带和马家滩段构造地质特征。以构造相对活动地区的相对稳定地段为铀矿找矿总体指导思想和部暑思路,笔者通过多年的铀矿地质勘查和研究,提出了逆冲推覆构造前缘带为铀成矿的有利地段。明确指出区内存在两期层间氧化作用,即早期以红色氧化为主,形成古氧化带;晚期以黄色氧化为主。两期层间氧化作用均对铀成矿有控制作用。早期红色氧化砂岩经历了逆冲推覆、抬升剥蚀、叠合埋深及断块分隔等后期改造作用;晚期黄色氧化作用沿背斜两翼发育,倾向于继承早期红色氧化并对其进行叠加改造。初步总结了区内的铀成矿特征及成矿规律。

The thesis discussed the geotectonie setting of west Ordos basin, classification of structural units, fault-fold belt and structural feature of Majiatan region. Finding the stable segment in the strong structural activiation region was used as the overall guidance for the uranium research and exploration, the fore part of an over thrust nappe belt was proposed as the favorable segment for uranium mineralization in the west of Ordos basin after several years research and exploration. Two oxidation layers of red and yellow colour was identified which the earlier oxidation was red and later oxidation alteration was yellow. The uranium ore was controlled by these two oxidation layers. The early red oxidized sandsone was experienced post-reformation such as thrust pushover, liftting, erosion and burry, block fault separation, the late yellow oxidation tended to inherit the early red oxidation and carried on the superposition modification distributed along the both wings of anticline. The thesis summarized the uranium features and metallogenic pattern which can be used as the guidance for uranium exploration in the basin.