【摘要】 在干旱半干旱地区 ,封闭湖泊的湖水盐度对气候变化反应敏感。首先通过现生介形类 (Lim nocytherecf.inopinata)壳体与湖水Sr/Ca比值的测定确定了Sr/Ca的分配系数 ;然后测试现代岱海湖水盐度与湖水Sr/Ca比值 ,建立湖水盐度与湖水Sr/Ca比值的函数关系 ;最后利用湖泊沉积剖面中介形类壳体的Sr/Ca比值定量恢复了岱海湖水近 80 0a来的盐度。通过分析岱海湖水盐度变化过程 ,揭示了研究区小冰期前期降水增加的冷湿气候 ,这明显不同于东部其它地区的冷干气候 ;研究区在小冰期中后期以偏干旱气候为主 ,这与东部其它地区干冷气候相一致 ;推测了 2 1世纪初 10～ 2 0a ,岱海地区降水将有所增加 ,干旱趋于缓和。更多还原

【Abstract】 The salinity of lake water is a sensitive monitor of climate in arid and semiarid region. The paleo-water salinity in the past 800 years was reconstructed quantitatively by Sr/Ca ratios of ostracodes ( Limnocythere cf. inopinata) in the Daihai Lake sediment core, by establishing the function between Sr/Ca ratio and salinity of lake water, and determining the partition coefficient (K d) of Sr/Ca in ostracodes (Limnocythere cf. inopinata). The processes of paleosalinity change showed the main climate information as follows: (1) Different from cold-dry climate in other part area of North China, Daihai Lake region was characterized by cold-wet climate in the early period of the Little Ice Age(LIA). (2) During the middle and later period of LIA, this region was mainly controlled by relatively dry climate, being consistent with other area in the East China. (3) It is supposed that the precipitation will increase in 10 ～ 20 years in Daihai Lake region, alleviating the arid situation.更多还原