老挝万象平原钾盐矿床控矿构造研究

老挝万象平原钾盐矿层赋存于新近系古新统塔贡组中,主要含钾矿物为光卤石,少量钾石盐.成矿期塔贡组及钾盐矿层主要受北西向的边界断裂及塔贡向斜控制;成矿期后钾盐矿层主要受褶皱(盐向斜、盐背斜)控制.在钾盐矿层沉积后,先在水平应力作用下形成宽缓褶皱.由于向斜部位相对沉降,沉积速度较快,钾盐矿层上部的碎屑岩较厚;而背斜部位相对上...

ORE CONTROL STRUCTURE STUDY ON POTASH DEPOSITS OF VIENTIANE PLAIN IN LAOS

Potash ledge of Vientiane plain in Laos host in Paleocene Tagong group of Neogene System,the principal potassium-bearing minerals are carnallite and a few halosylvite.The Tagong group minerals and potash ledge are controlled by NW bordering fault and Tagong syncline at ore-forming stage,but by potash syncline and anticline after ore-forming stage.The upper part of the potash ledge have thicker clastic rocks for faster sedimention at degressive syncline but have thinner clastic rocks at rising anticline.Some differential loading produced at the potash ledge between anticline and syncline for the density contrast between potash ledge and clastic rocks as well as the different thickness of clastic rocks.Some potash anticlines have formed after ledge incrassation at anticline area for the load plastic flowing to the anticlines at syncline area.For the same reasons,it became more thinner at the syncline ledge,but increased at anticline area,with shallow burying,it caused lacuna at superjacen the succeeding anticline development caused the potash ledge broken after exposing in the fresh water.