Method for determining mineralization age of sandstone-type uranium ore in basin

Abstract

The invention discloses a method for determining a mineralization age of a sandstone-type uranium ore in a basin, belonging to the technical field of sandstone-type uranium ore in the basin. The method for determining the mineralization age of the sandstone-type uranium ore in the basin comprises the following steps: step (1), selecting a deposit and a target layer to determine a stratigraphic aget0 of an ore-bearing construction; step (2), collecting an ore sample; step (3), performing polished thin section grinding on the ore samples; step (4), performing particle size statistics on the polished thin section; step (5), breaking the samples according to the particle size level classification result, and dividing the samples according to the particle levels; step (6), performing total rock U-Pb isotopic dating on the classified samples with different particle size levels, and performing isochron age calculation meanwhile; and step (7), determining the uranium mineralization age according to the isochron age and the stratigraphic age t0. The method for determining the mineralization age of the sandstone-type uranium ore in the basin disclosed by the invention can accurately determine the formation age of the basin sandstone-type uranium ore, and eliminate the influence of the uranium-containing debris particles in the sandstone to the greatest extent, thereby maximally approaching the true formation age of the uranium ore.

Description

technical field [0001] The invention belongs to the technical field of sandstone-type uranium deposits in basins, and in particular relates to a method for determining the ore-forming age of sandstone-type uranium deposits in sedimentary basins. Background technique [0002] The precise determination of metallogenic age is a golden key to understand the metallogenic regularity of ore deposits and predict the prospecting target area. However, the metallogenic chronology of sandstone-type uranium deposits in the basin is currently facing enormous difficulties and challenges, and it is a world problem that needs to be solved urgently. This is mainly because the ore-forming system of this type of deposit is completely open, and the uranium ore is subjected to continuous destruction and transformation. At the same time, the grade of sandstone-type uranium deposits is usually low (industrial grade 0.01%), and the size of new (secondary) uranium minerals is generally only 0.n—n (μ...

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