中文摘要：

总结了青藏高原地区400多个湖泊湖水的Mg2＋、Ca2＋和Mg/Ca等水化指标与湖水盐度的相关关系,以及这种关系随着湖水变化（不同采样时间和采样点以及自然蒸发）而产生的变化规律.结果表明：青藏高原湖泊湖水的Mg2＋浓度与盐度具有较为稳定的正相关关系,而Ca2＋和Mg/Ca与盐度的相关性较弱.在对于某一特定水化学类型的湖泊,一般碳酸盐型湖泊的Mg2＋、Ca2＋以及Mg/Ca等指标与盐度均没有明显的相关性;硫酸盐型湖泊中Mg2＋浓度和盐度呈现较高的正相关关系,而Ca2＋以及Mg/Ca与盐度的相关性仍很弱;而在氯化物型湖泊中,Mg2＋浓度与盐度呈更高的正相关性,Ca2＋浓度也与盐度呈一定的正相关性,Mg/Ca这一指标与盐度的相关性依然很弱.而对某一特定湖泊,在不同演化阶段或不同的采样地点,Mg2＋浓度与盐度仍然保持明显的正相关关系,而Ca2＋以及Mg/Ca与盐度的相关性仍然不稳定或很弱.在青藏高原作古环境重建应用的时候,湖水Mg2＋浓度是古盐度一个较好的转换指标,而Ca2＋以及Mg/Ca的古盐度指示意义相对较弱.

英文摘要：

This paper summarizes the relationships between hydrochemical proxies of Mg2＋,Ca2＋,Mg/Ca and the salinity from more than four hundred lakes in the Qinghai-Tibetan Plateau.We discuss its variation characteristics by different samples from varied place and time,as well as natural evaporation.Mg2＋ shows a stable positive relationship with salinity in lakes in the Qinghai-Tibetan Plateau,while Ca2＋,Mg/Ca show poor and unstable relationships with salinity.For carbonate water types in the lakes,however,no significant relationship is observed between Mg2＋,Ca2＋ and Mg/Ca and salinity in carbonate typed lakes.Mg2＋ shows positive relationship with salinity in sulphate typed lakes,and Ca2＋,Mg/Ca remains poor relationship with salinity.While in chloride typed lakes,Mg2＋ shows distinct positive relationship with salinity,and Ca2＋ also shows positive relationship to some extent with salinity.Mg/Ca still shows no clear relationship with salinity.In individual lakes,Ca2＋ and Mg/Ca still show unstable and/or poor relationship with salinity,while Mg2＋ keeps remarkable positive relationship with salinity.It is concluded that Mg2＋ is a useful indicator for paleosalinity reconstruction in the Qinghai-Tibetan Plateau.