内蒙古多伦山间盆地砂岩型铀矿新发现及找矿前景

核工业二〇八大队在内蒙古东南部中生代火山岩区多伦山间盆地首次发现了砂岩型工业铀矿化。为了揭示其铀矿化类型、铀成矿条件、成矿作用及找矿前景，在盆地内开展了野外地质、微观特征、岩石学、矿物学、地球化学及矿化规律等方面的研究，并讨论了新发现的砂岩型铀矿化特征及成矿条件。认为多伦盆地中生代强烈的火山活动与基底塌陷为含铀建造的形成提供了良好的构造环境，广泛分布的酸性火山岩提供了充足的铀源，目的层砂体疏松透水、厚度适中（约40 m），利于含氧含铀水的持续渗入，且具有完整的氧化还原分带性，利于铀成矿。根据已有勘查成果，结合盆地演化及区域山间盆地的广泛分布，认为多伦山间盆地具有较好的铀找矿前景，深部可能存在富厚矿体，下一步铀矿勘查应重视多伦古河道两侧的边滩沉积。 

New discovery and prospecting prospect of sandstone type uranium deposits in Duolun Intermountain Basin,Inner Mongolia

This paper reports the first discovery of sandstone type industrial uranium mineralization in the Duolun Intermountain Basin in the Mesozoic volcanic rock area of Southeast Inner Mongolia by No.208 Geological Party, CNNC.In order to understand the type of uranium mineralization, uranium metallogenic conditions, mineralization and prospecting prospects, the field geological phenomena, microscopic characteristics, petrology, mineralogy, geochemistry and mineralization patterns were studied in the basin.This paper discusses the characteristics and metallogenic conditions of the newly discovered sandstone type uranium mineralization.The strong Mesozoic volcanic activity and basement subsidence in Duolun Basin provided a good tectonic environment for the formation of uranium bearing formations.The widely distributed acidic volcanic rocks provide abundant uranium sources.The sand body of the target layer is loose and permeable, with moderate thickness (about 40 m), which is conducive to the continuous infiltration of oxygen-containing and uranium-containing water, and has complete oxidation-reduction zoning.All these are favorable for uranium mineralization.According to the existing exploration results, combined with the basin evolution and the wide distribution of regional Intermountain Basins, it is considered that the Duolun Intermountain Basin has a good prospecting prospect for uranium, and there may be rich and thick ore bodies in the deep.In the next step of uranium exploration, attention should be paid to the lacustrine deposits and beach deposits on both sides of the Duolun ancient river.