老挝东泰钾盐矿区矿床控矿因素探析

Primary Study on Orecontrolling Factors of Sylvine Mining Areas in Dongtai of Laos

摘要:

通过对区域地质、构造和岩相古地理的研究，从成矿阶段的角度，将控矿因素分为背景控矿因素、沉积控矿因素、改造控矿因素。得出：背景因素为区域性盆地沉积环境形成条件；沉积控矿因素直接控制了工区石盐矿层的层理形态；改造控矿因素中，局部构造对矿层的改造是矿区盐层多呈背斜分布且轴部较两翼矿层大幅变厚的原因，钾石盐出现在光卤石矿层顶部是因为上部裂隙水或者封存的老卤水向下侵蚀光卤石矿层顶部，溶蚀了溶解度相对较大的MgCl2,而溶解度相对较小的KCl被保留下来,从而多在上盐层光卤石矿顶部形成再生或次生钾石盐矿。

Abstract:

Through study on regional geology, structure and lithofacies paleogeography, from the aspect of mineralization, orecontrolling factors can be divided into background of orecontrolling factors, deposition orecontrolling factors and transformation orecontrolling factors. It is concluded that background orecontrolling factors are the forming conditions for sedimentary environment of regional basins; deposition orecontrolling factors directly control the bedding patterns of the rock salt layers; while in transformation orecontrolling factors, the transformation of local structures to layers will cause the saltbed distributed in anticline, and the saltbed in axis partis are thicker than in the wings. Sylvite occurred on the top of carnallitebed, because the upper fracture water or old brine eroded carnallitebed from the top to down part, and eroded MgCl2 with relative high solubility, while KCl with relative low solubility was preserved. Thus, recrystallized or secondary crystallized halite had been formed on the top of carnallite bed.