青海省尕斯库勒盐湖卤水水化学特征初步研究

通过尕斯库勒盐湖3种卤水(盐田卤水、晶间卤水和湖表卤水)的水化学成分、化学类型、相图研究,初步揭示了该湖不同类型卤水的水化学特征。研究表明,3种卤水的Ca2+、Mg2+、Cl-、SO24-、HCO3-均比柴达木盆地盐湖平均值高,尤以盐田卤水为高,然而K+、Na+相对较低。微量离子均匀性:晶间卤水>湖表卤水>盐田卤水;主要离子均匀性:湖表卤水>晶间卤水>盐田卤水。卤水划分为硫酸镁亚型和氯化物型两类,没有发现硫酸钠亚型和碳酸盐型。其中,盐田卤水全部为氯化物型;晶间卤水既有硫酸镁亚型也有氯化物型,硫酸镁亚型占41.67%,氯化物型占58.33%;湖表卤水大部分为氯化物型。总体而言,卤水变质程度较深,其中盐田卤水变质最深,湖表卤水次之,晶间卤水变质程度较浅。盐田卤水、晶间卤水、湖表卤水在Na+,K+,Mg2+∥Cl-,SO24--H2O五元体系介稳相图中的位置差别较大,表明各类卤水在演化阶段上存在较大差别。

Priliminary Study of the Hydrochemical Characteristics of Brines in the Gas Hure Salt Lake,Qinghai Province

Based on the hydrochemical composition,hydrochemical type and metastable phase diagram,this paper priliminary discussed the hydrochemical characteristics of three types brines(salt-bond brine,intercrystalline brine and superficial brine)in the Gas Hure Salt Lake.The average contents of Ca2+、Mg2+、Cl-、SO2-4、HCO-3 existed in three types brines were all higher than those in Qaidam Basin's brines,while salt-bond brine higer than intercrystalline brine and superficial brine.However,K+ and Na+were reversely.The trace elements' uniformity,intercrystalline brine>superficial brine>salt-bond brine;the major ions' uniformity,superficial brine>intercrystalline brine>salt-bond brine.The results showed that the brines belongs to chloride type and magnesium sulphate subtype,none of sodium sulphate subtype and carbonate type.Among all of the brines,salt-bond brine belong to chloride type;intercrystalline brine belong to chloride type and magnesium sulphate subtype,magnesium sulphate subtype account for 41.7% and chloride type account for 58.33%;most of the superficial brine belong to chloride type.In a word,brines underwent relatively deep metamorphy,salt-bond brine>superficial brine>intercrystalline brine.The location of three types brines in quinary system metastable phase diagram of Na+,K+,Mg2+∥Cl-,SO2-4-H2O were quite differently.There existed a great difference at the evolution stages.