泰国—老挝境内的呵叻高原马哈萨拉堪组钾盐矿床是世界上最大的钾盐矿床之一。综合研究表明,马哈萨拉堪组赋钾蒸发岩形成于晚白垩世,其成盐物质来自海水。该含盐建造很可能形成于陆相环境中,为"海源陆相"沉积。在蒸发岩沉积过程中及沉积后,一直伴随着水—岩(盐)作用的发生,钾盐沉积之后往往受到该作用的改造。溢晶石的出现是该地区"异常"蒸发岩的表现特征之一,它的形成很可能与海水的变质作用有关,但其形成机制尚未得到合理解释。兰坪—思茅盆地勐野井组与呵叻高原马哈萨拉堪组联系密切且具有共同之处,但二者在时代、成盐期次对比等问题上存在较大争议。最后,针对今后该地区钾盐研究提出了一些新的研究思路与方法。
The Maha Sarakham Formation potash deposit on Thailand-Laos Khorat Plateau is one of the largest potash deposits in the world. Comprehensive studies show that the formation formed in late Cretaceous and was de- rived from seawater. Probably the formation formed in a continental setting and was a set of the "seawater-derived but terrestrial" deposits. The water-rock/sah reactions happened not only during sedimentary process but also after post-deposition. The post-depositional potash deposits were often reworked by these reactions. Occurrence of tachy- hydrite is one of the characteristics of "abnormal evaporites" in this area and the formation of the mineral probably was related to the metamorphism of Cretaceous seawater. The forming mechanism of tachyhydrite can not be well understood until today. The relationship between Menyejing formation in Lanping-Simao Basin and Maha Sarakham Formation on Khorat Plateau. is very close and there are some common characteristics in two formations. But there has been much controversial in some problems such as age, comparison of salt-forming periods, etc. Finally, ai- ming at the future studies of potash deposits in this area, some new ideas and methods are put forward.