东准卡姆斯特地区中侏罗—渐新世古气候环境分析及对砂岩型铀矿的影响

砂岩型铀矿属沉积盆地内表生水渗入成矿类型,古气候条件、沉积环境对含矿建造的形成、后生改造及铀元素的富集成矿等具重要影响。本次研究主要对该区内多个钻孔不同层位、不同颜色岩石系统采样测试,据测试结果对卡姆斯特地区不同地质时期岩石地球化学特征及古气候条件、沉积环境进行研究,并探讨古气候条件对该区铀元素迁移富集的影响。本次共采取234件侏罗—新近系岩石样品,开展常、微量元素分析、有机碳含量分析及粘土矿物相对含量分析。结果表明,从中侏罗世西山窑期至古近纪中晚期研究区气候总体为温湿-干旱,中侏罗世头屯河期早期沿袭了温湿气候,后期逐渐向干旱转变,为一个气候过渡期,有利于卡姆斯特地区与氧化带相关铀成矿作用的发育。

Middle Jurassic-Oligocene Paleoclimate Environment and its Influence on Mineralization of Sandstone-type Uranium Deposit in Kamuster Area,Eastern of the Junggar Basin

The sandstone-type uranium deposit belongs to the type of the mineralization that sedimentary basin in which the surface water infiltrates for mineralizing,the paleoclimatic conditions and depositional environment have important effects on the construction of ore-bearing, the epigenetic alteration and the enrichment of uranium elements for mineralization. In this study, the systematic sampling and testing of rock samples from different layers and various color rock systems in multiple boreholes in this area were carried out.According to the test results, the geochemical characteristics of rocks formed in different geological periods,paleoclimatic conditions and sedimentary environment in Kamuster area were studied, and the influence of paleoclimatic conditions on the migration and enrichment of uranium elements in this area was discussed.In this study, a total of 234 Jurassic-neogene rock samples were taken for the analysis of ordinary and trace elements,organic carbon content and relative content of clay minerals.The results show that the area from the Xishanyao period in middle Jurassic to the middle-late paleogene had a climate that is generally by temperature humiditydrought, the early of Toutunhe period in middle Jurassic followed humid climate,which gradually became drought in the late and it was a transitional climate that is benefit to the development of regional uranium mineralization is associated with the oxidation zone in this area.