贵州福泉牛场向斜勘查区铌钽矿床地质特征及勘探前景分析
Geological characteristics and exploration prospect of niobium tantalum deposit in Niuchang syncline exploration area, Fuquan, Guizhou
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摘要:
针对福泉牛场向斜勘查区二叠系吴家坪组底部凝灰岩层段,运用野外地质调查、样品采集及元素分析等工作方法,对勘查区地质背景、铌钽矿床的含矿层位、矿体特征、矿体成因及勘探前景等开展研究分析。通过分析可知:①勘查区内含矿层系位于海相沉积的吴家坪组底部凝灰岩层段,为风化壳型沉积铌钽矿床,通过与上覆地层及下伏地层对比,勘查区内铌钽矿含矿层系测井曲线表现为放射性异常,幅值显著高于邻近岩石,赋存稳定,厚度变化为0.60~8.51 m,平均为2.80 m,实验初步显示区内铌钽矿主要以(Ta, Nb)2O5形式存在,12个钻孔样品的测试(Ta, Nb)2O5平均含量为0.024 0%,高于最低工业品位的0.016%;②勘查区内铌钽矿赋存层位潜力较大,开展进一步勘探工作十分必要。同时,勘查区内铌钽矿体的发现也表明区域上海相沉积区特定的地质、地球化学环境中可能同样富集该矿床,因此在贵州东部海相含煤沉积区可以扩大勘查范围,以期发现更大规模的铌钽矿体。
Abstract:In view of the tuff layer at the bottom of the Permian Wujiaping Formation in the Niuchang syncline exploration area of Fuquan, field geological survey, sample collection and element analysis are used to study and analyze the geological background, ore-bearing strata, ore body characteristics, ore genesis and exploration prospect of niobium and tantalum deposits in the exploration area.The following conclusions can be drawn from the analysis.The ore-bearing strata in the study area are located in the tuff layer at the bottom of Wujiaping Formation, which is a weathered crust-type sedimentary niobium-tantalum deposit.Compared with the overlying and underlying strata, the logging curve of niobium-tantalum ore-bearing strata in the study area shows abnormal radioactivity, the amplitude is significantly higher than that of adjacent rocks, and the occurrence is stable.The thickness change is 0.60-8.51 m, with an average of 2.80 m.The experiment shows that the niobium-tantalum ore in the study area mainly exists in the form of (Ta, Nb)2O5.The average content of (Ta, Nb)2O5 in 12 borehole samples is 0.024 0%, which is higher than 0.016% of the lowest industrial grade.The occurrence horizon of niobium and tantalum ore in this area has great potential, and it is necessary to carry out further exploration.At the same time, the discovery of niobium and tantalum ore bodies in this area also shows that the deposit may also be enriched in the specific geological and geochemical environment of the regional marine sedimentary area.Therefore, the exploration scope can be expanded in the marine coal-bearing sedimentary area in eastern Guizhou, in order to find more large-scale niobium and tantalum ore bodies.