Homogenization temperature and its significance for primary fluid inclusion in halite formed in Modern Chaka Salt Lake, Qardam basin

摘要

Our long-term field observation for Chaka Salt Lake located in eastern Qardam Basin indicates that the halite precipitates mainly in July or August every year (Fig.1). Accordingly, we made a detailed observation of twenty day's duration for the halite precipitated, air and water temperature, and their relationships in August 2005. The results show that water temperature is generally higher than air temperature, especially when air temperature exceeds 20 ℃(Fig.2), and the exponential relation between air and water temperature is better than linear relation between them (Fig.3).In a certain day, water temperature progressively goes up as the air temperature increases. Halite begins to precipitate only when water temperature reaches 25 ℃ between 12 and 13 pm, but it is granular and cannot be easily preserved. If water temperature keeps in 25 ℃ for a few days, halite precipitated can be preserved. If water temperature reaches and exceeds 30 ℃ between 13 and 15 pm at one day, halite will precipitate fast and can be well preserved. As the air temperature decreases after 4:00 pm, water temperature also decreases, and little halite precipitates (Fig. 2).