冰冻成因卤水的水化学标志──Ⅰ.卤水的δD值

HYDROCHEMICAL SYMBOL OF BRINES FORMED BY SEAWATER FREEZING──Ⅰ.δD VALUE OF BRINES

于1998年3-7月间进行了一系列有关海水结冰析盐和海水蒸发浓缩形成卤水的室内模拟实验，并对实验中得到的冰样和卤水样进行了化学组成和同位素组成分析。实验结果表明，与原来的海水相比，在上述两个自然物理过程中形成卤水的δD值随卤水浓度的升高表现出两个明显相反的变化趋势：在海水结冰析盐形成卤水过程中，卤水的δD值表现出逐渐降低的趋势；而在海水蒸发浓缩过程中，卤水的δD值却表现出逐渐增高的倾向。因此，对同一海水来源的卤水体来说，δD值可以作为判别该卤水是冰冻成因还是蒸发成因的一个重要水化学标志。

Indoor modeling experiments for seawater freezing and evaporating into brine were carried out in order to identify the hydrochemistry symbol of the brine formatted by seawater freezing. In these experimend, a oneallmensional and single directory freezing model and a naturally evoprating model were thepted; as a result of the experiments, 5 ice columns, 5 freezing and 2evaporating brine sampes were obtalned. The chemistry compositions and the stable hydrogen isotop constitutions were analyzed for the residtal brines and for the ice. The value of δD, whose behavior during the freezing of seawarer is repoded here, shows a distinct bend between two physical processes of seawater freezing and seawarer evaporating, compared to the original seawater.In the pngess of seawater freezing, the 6D values of brines decrease in response to an increase in itS concentration. However, in the process of seawarer evaporating, they show an increase trend.Hence, the δD value of brines can be used as a hydrochemical symbol for distingulshing brines formed by seawater freezing with those formed by seawater evaporating.