新疆现代盐湖的含钾特征及塔里木盆地的成钾远景

THE POTASSIUM-BEARING CHARACTERISTICS OF MODERN SALT LAKES AND POTASSIUM-FORMING PROSPECT OF TARIM BASIN, XINJIANG

新疆有现代盐湖50余处,固液相矿产覆盖面积约7000～10000km^2。在固、液相盐类矿产中,都含有钾,但富集成矿的不多。在卤水中钾的富集与镁的关系密切,与卤水的演化程度及分异情况有一定关联。钾在固相盐类矿产中,富集于顶部石盐壳的某些地段。其富集规律与镁含量相关。NO_3^(-1)在固相钾矿的成矿过程中往往起重要作用,SO_4^(2-)也参与活动,形成独特矿床。其形成过程与毛细作用有关。在塔里木盆地东缘及吐—哈盆地西段,寻找同类钾矿床远景比较广阔。塔里木盆地及周边古蒸发岩分布广泛,厚度较大,地质历史上持续时间较长,具有寻找古钾盐的地质前提,但古蒸发岩沉积环境变化较大,后期改造剧烈,给寻找古钾盐工作带来很大难度。如选好突破口,采用符合实际的工作方法,可能会有所突破。

More than 50 modern salt lakes cover an area of about 7 000-10 000 km2 with salt deposits of solid or liquid facies , mostly bearing potassium but few concentrated. The concentration of potassium in the brine is closely associated with magnessium, and to some degree related to the evolution grade and differentiation of the brine. Potassium usually concentrates at the rock salt shell of the top in the salt deposits of solid facies. Its concentration regularity is related to the content of magnesssium. The NO51- usually takes an important role in the mineralization of the sylvite of solid facies. The participation of SOS' forms a peculiar deposit associated with capillarity. The sylvite of the same type is likely to be found in the eastern part of Tarim and western section of Tu -Ha basin. The paleo-evaporites are extensively distributed in Tarim Basin and its surroundings, characterized by great depth and long history. However the sedimentary enviroment of paleo-evaporite changed a lot and affected by later reform, thus creating a great difficulties in the search of sylvites. But the selection of a breakpoint and a practical methodology will help to go out of the difficulties.