云南兰坪-思茅盆地勐野井矿区钾石盐的特征及其沉积环境

本文运用X射线粉晶衍射(XRD)、透射电镜-能谱(TEM-EDS)和工业C T等方法,对云南江城勐野井钾盐矿床580m运输坑道地质剖面钾矿石的特征进行了研究。XRD和TEM-ESD结果给出,矿石中的盐类矿物主要是石盐、钾石盐、硬石膏和菱镁矿,钾石盐主要赋存在青灰色岩盐和灰绿色泥砾质岩盐中。CT结果表明,青灰色钾盐矿体中的石盐呈近似圆形和棱角分明的角砾,钾石盐沿石盐角砾的边缘呈条带状或不规则状分布,在条带状的内部可见钾石盐呈粒状或团块状分布,其中粒状钾石盐可能以八面体和立方体为主,而团块状钾石盐无特定晶形。钾石盐的这种分布特征表明,该盐类矿床在蒸发沉积过程中,早期沉积的石盐体呈遭受外力破坏,后期形成的钾石盐沿其裂隙沉积,表明钾石盐形成晚于石盐,且可能有多次沉积。

Characteristics of Sylvite at the Mengyejing Potash Deposit in the Lanping Simao Basin, Yunnan

We studied the characteristics of potassium ore in the 580m tunnel section of Mengyejing Potash Deposit, Yunnan by XRD, TEM EDS, and CT methods. The results of XRD and TEM EDS show that the main salt minerals are halite, sylvite, anhydrite, and magnesite. Sylvite exists in green grayish salt rock and gray green mud gravel salt rock. CT analysis also gives that halite shows circular and angular breccia in green grayish salt rock, and sylvite is banded or irregular shape along the edge of halite breccia. In the banded sylvite, we can see granular or lumpy sylvite, single granular sylvite is octahedral and cube, and lumpy sylvite is no specific form. The distribution characteristics of sylvite show that the formation of halite is earlier than sylvite, after the halite was destroyed by external forces, the deposition of sylvite is along halite fracture, and there may be multiple deposits.