哈达贺休盐湖卤水氢氧同位素特征及成因分析

Hydrogen and Oxygen Isotope Characteristics and Origin of Hadahexiu Salt Lake Brine

中文关键词:  哈达贺休盐湖  地下卤水  氢氧同位素  氘盈余  成因分析

英文关键词:Hadahexiu salt lake  Underground brine  Hydrogen and oxygen isotopes  Deuterium surplus  Genetic analysis

中文摘要:

      内蒙古哈达贺休盐湖蕴藏着较为丰富的地下卤水资源,但对其成因和演化机制尚缺乏充分的认识。采用稳定同位素方法,研究了哈达贺休盐湖地下卤水及其周边水体的氢氧同位素组成特征,并对卤水的成因进行了分析。结果表明:哈达贺休盐湖地下卤水的δD和δ¹⁸O值平均值分别为-0.53 ‰和4.01 ‰,黑河河水的δD和δ¹⁸O值平均值分别为-36.73 ‰和-5.51 ‰,居延海湖水的δD和δ¹⁸O值平均值分别为1.26 ‰和2.73 ‰,当地大气降水的δD和δ¹⁸O值平均值分别为-5.30 ‰和-1.20 ‰。研究区水体的蒸发趋势线方程为δD=5.32δ¹⁸O-20.08,该蒸发线偏离全球大气降水线。黑河河水的氘盈余值(d)最大,湖水和地下卤水d的最小,而且湖水和卤水的d值与TDS呈负相关关系。偏正的δD和δ¹⁸O值以及较小的d值,表明研究区卤水经历了强烈的蒸发,同时还存在与含氧类矿物的同位素交换反应。卤水和居延海湖水氢氧同位素值分布比较集中,并且接近,二者都由黑河河水演化而来。

英文摘要:

      Hadahexiu Salt Lake in Inner Mongolia is enriched in underground brine,its origin and evolution are not fully studied yet.This paper analyzed the hydrogen and oxygen isotopes in underground brine of Hadahexiu Salt Lake and the surrounding waters for tracing the origin of the brine.Results indicate that:the mean value of δD and δ¹⁸O are respectively-0.53 ‰ and 4.01 ‰ of the underground brine of Hadahexiu Salt Lake,-36.73 ‰ and-5.51 ‰ of Heihe River,1.26 ‰ and 2.73 ‰ of the Juyan Lake water,-5.30 ‰ and-1.20 ‰ of local precipitation.The evaporation trend line of the waters in the research area deviates from the global meteoric water line according to the formula δD=5.32δ¹⁸O-20.08.The deuterium surplus value d of Heihe River is the highest and the lowest that of the lake water and the underground brine,while the lowest d value displays negative correlation with TDS.The positive values of δD and δ¹⁸O and the lower d values suggest that the waters in the research area has gone through intensive evaporation along with isotopes exchange reaction of oxidiferous minerals.Hydrogen and oxygen isotope values of the brine and Juyan Lake are comparable,indicating that both are evolved from Heihe River.