There is a lot of sulfate, dolomite and magnesite in Changdu Basin of Tibet. It is of great significance to study the formation of potassium potential of this area. The authors collected 12 salt spring samples and 2 spring samples during the process of evaporites mines investigation in Changdu Basin. From the research of elements and hydrochemical coefficient, the results indicate that salt spring samples are mainly about chloride type and Sodium sulfate sub-type, the formation of salt spring seems to be attributed to eluviation brine of halite ,and these salt spring are also leached by small amounts of carbonate rock and sulfate salt rock. The salt spring samples of Naxi Village also influenced by deep circulatory brine at the same time. The degree of salt spring concentration such as Cl ,Na and salinity show that the trend of the degree of brine concentration in Changdu basin was gradually reduced from north to south, their contents of Br, Li, B was gradually increased from Gongjue to north, and it also increased from Gongjue to south, which is relatively low. The salt spring samples has the nature of the inland salt lake in study area. There is a tendency that marine sedimentary environment transition into continental sea sedimentary environment gradually from north to south in Changdu Basin, the northern salt-belt has strong marine characteristics and the southern salt-belt has land surface water impact. The studies show that the saliferous formation of Leiwuqi has experienced the most intense evaporation, concentration and eluviation, the stage of brine concentration in Leiwuqi Salt-belt was previous to the Naxi and Gongjue Salt-belt,and the ore-forming environment in the Leiwuqi Salt-belt is better than the Naxi and Gongjue. Salt-belt. The Gongjue area can be considered to be one of the most promising areas in search for potash ore. The salt spring samples of Naxi and Gongjue was influenced by the land surface water. It is indicated that the potassium-forming prospect of Nangqian-Changdu-Lanping Basin became increasingly better from north to south. |