新疆伊犁盆地蒙其古尔地区下侏罗统三工河组沉积相及其与铀矿化的关系

发布时间：2019-06-12 19:03

【摘要】：新疆伊犁盆地蒙其古尔矿床是近年来发现的大型砂岩型铀矿床。以下侏罗统三工河组为主要研究层位,通过岩性特征、沉积构造和沉积序列分析及露头描述和剖面对比,从沉积学的角度解释蒙其古尔矿区铀矿化的发育条件和成矿机制。研究认为,蒙其古尔地区三工河组以扇三角洲前缘沉积为主,水下分流河道、分流间湾、水下决口扇等为主要沉积微相类型,河口砂坝不发育。该沉积微相对研究区铀矿化的影响主要体现在4个方面:(1)砂体的连通性为成矿流体提供运移空间;(2)水下分流河道微相是控制氧化带发育及矿体富集程度的主要影响因素;(3)沉积微相变化导致的砂体变异部位是矿体厚度、宽度与富集程度增大的主要原因;(4)由决口扇形成的泥岩天窗是越流形成的关键因素之一。
[Abstract]:The Mengqiguer deposit in Yili Basin, Xinjiang, is a large sandstone-type uranium deposit discovered in recent years. The following Jurassic Sangonghe formation is the main research horizon. Through lithologic characteristics, sedimentary structure and sedimentary sequence analysis, outcrop description and profile comparison, the development conditions and metallogenic mechanism of uranium mineralization in Mengqiguer mining area are explained from the point of view of sedimentology. It is considered that the Sangonghe formation in Mengqiguer area is dominated by fan Delta front deposition, underwater shunt channel, intershunt bay, underwater crevasse fan and so on, and the estuary sand bar is not developed. The influence of the sedimentary microphase on the uranium mineralization in the study area is mainly reflected in four aspects: (1) the connectivity of the sand body provides the migration space for the ore-forming fluid; (2) the underwater shunt channel microphase is the main influencing factor to control the development of the oxidation zone and the enrichment degree of the orebody; (3) the variation of the sand body caused by the change of the sedimentary microphase is the main reason for the increase of the thickness, width and enrichment degree of the orebody; (4) mudstone skylight formed by crevasse fan is one of the key factors in the formation of overcurrent.
【作者单位】：东华理工大学地球科学学院;中核集团核工业二一六大队;
【基金】：国家重点基础研究发展规划(973计划)(编号:2015CB453002) 整装勘查关键基础地质研究计划项目(编号:12120114007601)共同资助~~
【分类号】：P619.14;P534.52

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