赣南大埠重稀土矿床矿化富集规律与控矿因素研究

Study on the Ore-controlling Factors and the Mineralization and Enrichment Features of Dabu HREE Deposit,Southern Jiangxi Province

大埠花岗岩体风化壳中离子型稀土资源潜力大,被赣州市政府认定为赣南5个重稀土重点勘查区之一;大埠重稀土矿床是已查明的与该岩体相关的主要稀土矿床,研究其矿化富集规律和控矿因素对进一步找矿勘探工作具有重要意义。对大埠重稀土矿床探矿浅井品位和厚度资料及数字地形的统计和分形分析表明,矿体的品位和厚度主要受原岩的稀土总含量及地形地貌控制,地形多重分形幅宽Δα可以作为一种可靠的量化指标指示矿化富集规律,但难于精确地刻画矿化富集的空间分布;这是因为离子型稀土床的矿化富集是内、外生各种地质作用及环境因素和人类活动综合作用的结果。就某一矿区而言,矿体的品位和厚度虽然总体上受原岩的稀土总含量和地形地貌控制,但坡向、景观配置、母岩物质组成和结构的不均一性及人类活动等对矿体局部品位和厚度也有重要影响。

The weathered crust of Dabu granite rock body is considered to have great REE resource potential, and has been determined to be one of the five key HREE exploration areas in Southern Jiangxi Province by Ganzhou civic government. The study on the ore - controlling factors and the mineralization and enrichment features of Dabu HREE deposit is of great importance for the further exploration as it is the main proved REE deposit. By statistical and fractal analysis of grade and thickness data of orebody achieved by shallow shaft and digital terrain data of the deposit, it is suggested that the grade and thickness of orcbody are primary controlled by total REE content of parent rock and topography, and the width △α of topographical multi - fractal might serve as a reliable quantitative index for mineralization and enrichment, but it is difficult to predict accurately the spaeial distribution of mineralization and enrichment, for the mineralization and enrichment of ion absorption type REE deposit is a result of combined action of various kinds of endogenie and exogenous geologic processes, environment factors and human activities. As far as a single mining area concerned, the grade and thickness of orebody are primary controlled by total REE content of parent rock and topography, but slope aspect, landscape configuration, compositional and textural unevenness of parent rock and human activities have important effects on local grade and thickness of Orebody.