【摘要】 <正> 察尔汗盐湖是以石盐晶间卤水为主的第四纪陆相钾镁盐综合矿床,其中伴生有锂、硼、溴、碘、铷等有益元素。它不仅具有重要的工业价值,在矿床成因上更有它重要的理论意义。过去探讨其成矿地质条件的文章很多,但很少涉及可能影响矿床进一步扩大或富集的不利因素。笔者根据自己的实际工作,并参考了前人有关资料,试谈一点成矿地质条件,以资交流。更多还原

【Abstract】 The Qarhan deposit is a Quaternary terrigenous K-Mg saline depsit dominated by interstitial brines of halite crystals, associated with such useful elements as Li and B. It is not only of major industrial value but even more of major significance in metallogenic theories. On the basis of many years of field work and with reference to relevant data of predecessors, the author puts forward the following views about the conditions for the formation of this deposit.1. The Qaidam basin is characterized by inheritance. Prior to the Miocene, the Qilian, Kunlun and Altun mountains around the basin were still at the stage of moderate and low altitudes, and the basin was connected by water with the Tarim basin to the west and with the Gonghe basin to the east. Owing to the influence of the Himalayan movement, the Qaidam basin was gradually separated from the other basins and became as it is. The zone of saline sediments is distributed in NWW and NNW directions, coinciding to the trends of the Kunlun Mountains to the south and the Qilian Mountains to the north, which in the main reflects the configuration of the basement uplift and depression of the basin. On account of the influence of the basement structures, the basin is divided into the eastern and western parts. The eastern is a subsidence zone as well as a zone with potash salt concentration, while the western part is an erosion zone as well as a source area of potash supply for the eastern part.2. The sedimentary environments of the basin was originally favourable for the potash accumulation, thus leading to the formation of the Qarhan K-Mg saline deposit. Later, with the development of the basin, the lake water was cut up in place into several parts, thus affecting the concentration of potash. As a result of eastward migration, the lake water was far from the potash source—the western part of the basin, thus losing an important source of potash supply.3. Potash is derived from multiple sources, especially Tertiary saline clastic sediments, oil-field water, salt crusts or salinized soil resulting from capillarity and underground brines. On the other hand, though the metamorphic and magmatic rocks surrounding the basin contain potash minerals, they have certain limitations in acting as a potash source in a Iimited geological period as they were weathered slowly under arid and cold climatic conditions.4. In general the arid climate in the basin was favourable for the formation of a potash deposit. But as the climate was extremely arid in the western part of the basin after Pliocene and Pleistocene times. There was a lack of water media necessary for the continuous eluviation and transportation of K ions. Thus restricting the supply of potash in the western part of the basin to Qarhan.更多还原