二连盆地马尼特坳陷西部砂岩型铀矿成矿的沉积学背景  

Sedimentary Backgrounds of Sandstone-type Uranium Deposits in Western Manite Depression of Erlian Basin

作　　者：鲁超[1,2] 彭云彪[1,2] 刘鑫扬 焦养泉[1] 杨建新[2] 陈法正[2] 申科峰[2] 李荣林[2] 

机构地区：[1]中国地质大学资源学院,湖北武汉430074 [2]核工业208大队,内蒙古包头014010 [3]中核集团地矿事业部,北京100013

出　　处：《铀矿地质》2013年第6期336-343,共8页Uranium Geology

基　　金：核工业208大队铀矿生产科研项目"二连盆地马尼特坳陷下白垩统赛汉组沉积体系分析及其与铀成矿关系"资助

摘　　要：在二连盆地马尼特坳陷西部巴彦乌拉地区,有关赛汉组上段砂岩型铀矿储矿砂体的成因目前存有争议。笔者通过地震剖面、钻孔岩心分析和砂分散体系制图,对赛汉组上段进行了成因分析。研究发现,赛汉组具有特征的断坳转换期构造背景并由此决定了其优质铀储层的发育;赛汉组上段并非传统认识上的纵向辫状河成因,而是剥蚀残留的多个侧向上源自巴音宝力格隆起物源区的辫状河三角洲体系的集合体;构造反转和剥蚀作用对赛汉组地层进行了强烈改造,辫状河三角洲遭受强烈剥蚀,保存了具有多个朵状分割性的带状砂体,形成构造天窗和氧化带并发育铀矿化;砂体的平面非均质性控制了铀成矿作用,砂分散体系的变异部位、沉积相变部位是成矿的有利区域。It is very controversial about the genesis of the sand bodies which host sandstone-type uranium deposits in upper Saihan formation in Bayanwula area of western Manite depression. According to seismic section research, drilling core analysis and mapping of sand distribution, the upper Saihan formation shew typical tectonic background from fault depression to sag and determined the development of highquality uranium reservoir. The upper Saihan formation was not formed by braided stream in the longitudinal axis as traditional recognition. In fact, it is a aggregate of multi-braided deltas with the source from Bayinbaolige uplift which was denuded. Later structral inversion and denudation strongly reformed the Saihan formation, the braided delta suffered strong denudation, some sandbody was remained in multiple flower-shaped strip as the structral fenster in which oxidation was developed with uranium mineralization. Plane heterogeneous of sand body controls uranium mineralization, the variation parts of sand distributed system and sedimentary faces are the favourable region for uranium mineralization.

关 键 词：砂岩型铀矿 剥蚀作用 赛汉组上段 沉积体系 巴彦乌拉 

分 类 号：P612[天文地球—矿床学]