【摘要】 本文基于航空放射性K能谱数据再开发,结合野外地质调查、显微岩石学、元素地球化学等手段,分析并探讨了相山火山盆地航空放射性钾增量异常特征及其地质成因。研究表明,相山地区钾增量正值域与负值域呈NE带状相间分布,其空间延伸方位与地层的走向不一致,表现出跨地质单元现象,反映了增量场受断裂构造控制以及成岩后热液改造的基本属性。不同地质体钾含量存在差异,然而与正常未蚀变岩石比较,与铀成矿作用相关的水云母化蚀变岩石中的钾增量值表现出相对降低的趋势。钾增量亏损场(带)的形成与成矿流体在蚀变过程中具有"去钾"作用相关,是水云母交代钾长石作用的结果。铀矿床的定位与钾增量相对亏损场(带)具有良好的对应关系。根据钾增量相对亏损场可以大致圈定水云母化蚀变场,进而确定成矿流体活动范围,为铀成矿远景预测提供较为可靠的信息。更多还原

【Abstract】 This work is based on the redevelopment of K spectrometer data of airborne radioactivity,combination with field geological surveys,microscopic petrography,elemental geochemistry and isotope geochemistry and other means. The purpose is to analyze the incremental anomaly characteristics of airborne radioactivity in the Xiangshan area,Jiangxi Province and their geologic genesis. Research shows that positive and negative values of potassium increments show a NE trending belt-like pattern. Its strike is inconsistent with the formation trend,showing a phenomenon of crossing-geologic units,generally reflecting the basic attribute of the incremental field controlled by fault structure and post-diagenesis hydrothermal reformation. There are differences of potassium content in varied geologic bodies. However,compared with the normal unaltered rock,the potassium incremental values in the hydromicatizational altered rock,which is associated with the uranium mineralization,exhibit a relatively lowering tendency. The formation of the potassium incremental field is associated with the role of de-potassium ore-forming fluids in the process of alteration,which is the result of hydromica replacing K-feldspar. There is a good corresponding relationship between the location of the uranium deposit and the relative depleted field( zone) of potassium incremental values. According to this field,the hydromicatizational altered field can be roughly delineated,and the scope of the ore-forming fluid activity can be further determined,which provide more reliable information for prediction of uranium metallogenic prospect.更多还原