Changes of Stable Oxygen and Hydrogen Isotopes and Their Responses to Freezing Process in Dali-Nor Lake in Cold-Arid Areas of China
Li Wenbao
Li Changyou
Liu Xiaoxu
Zhen Zhilei
Hu Qitu
Liu Zhijiao
Abstract：Utilizing the environmental isotopes,which exist widely as one proxy of lake water evolution process,has become one important direction in lake sciences.In this paper,a total of 77 samples of lake water,ice and precipitation water were col-lected in Dali-Nor Lake,which locates in cold-arid areas of Inner Mongolia;and changes ofδD andδ1 8 O and their responses to freezing process in Dali-Nor Lake are analyzed.The comparison of the changes ofδD andδ1 8 O among lake ice,lake water and precipitate water shows that:(1)Following the freezing process,the values of ΔδD,Δδ1 8 O between bottom (65 cm)and sur-face (1 5 cm)ice layers are both above zero.But in fast stage and stable stage during lake ice forming,the change range of water stable isotopes is different.Meanwhile,the values ofδD andδ1 8 O in water under the ice are about 13.85 ‰ and 2.23 ‰ lighter than those in lake ice.In addition,the river inflows have more obvious influence on value changes ofδD andδ1 8 O among differ-ent sites in winter than in summer.(2)TheδD andδ1 8 O values of water (both summer and winter)and ice are both in right side of the global meteoric water line (GMWL)and local meteoric water line (LMWL),which shows that the evaporation process has certain influence on the fractional distillation of water stable isotopes before the lake ice formed.On the other hand, the values ofδD andδ1 8 O in lake ice and winter lake water have the same slope range and both in right side of the values ofδD andδ1 8 O in summer lake water,which shows that the freezing process has obvious influence on the fractional distillation of wa-ter stable isotopes during the lake ice forming process.
Keywords：hydrogen isotopeoxygen isotopefreezing processDali-Nor Lakecold-arid areageochemistry
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 2091-2100 )