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本文根据新疆艾比湖ZKooB孔中30个氧碳同位素样品的测试数据,制作了艾比湖最近二万年来的氧碳同位素变化曲线。氧碳同位素记录的研究表明,最近二万年来艾比湖的δ~(18)O变化主要是受湖水的蒸发作用和淡化过程所控制。艾比湖的水体环境在最近二万年中至少经历了八次明显的波动变化,δ~(18)O变化所反映的环境演变过程与全球性气候变化基本一致。二万年来δ~(13)C值的波动主要受湖泊水体中TDIC变化以及湖泊水体与大气CO_2间碳交换的制约。δ~(13)C值在5kaB.P.及10.5kaB.P.前后的异常降低,分别是由于全新世“新高温期”中的降温事件以及晚冰期“新仙女木”气候突变与快速降温所致。这是我国干旱区封闭湖泊连续沉积记录中,第一次所获得的关于五千年前降温事件以及“新仙女木”气候突变事件在碳同位素记录方面的直接证据。
According to the test data of 30 oxygen and carbon isotopes in the ZKooB pore in Lake Aibi, Xinjiang, the oxygen and carbon isotope curves of Lake Aibi over the past 20000 years have been produced. Oxygen and carbon isotope records indicate that δ 18 O changes in the Lake Aibi in the recent 20,000 years are mainly controlled by the evaporation and desalination of the lake. The water environment of Lake Aibi has undergone at least eight significant fluctuations in the last 20,000 years. The δ (18) O changes reflect basically the same environmental changes as global climate changes. The fluctuation of δ ~ (13) C value over 20,000 years is mainly controlled by the change of TDIC in lake water and the carbon exchange between lake water and atmosphere CO_2. The anomalous decrease of δ ~ (13) C values before and after 5 kaB.P. and 10.5 kaB.P. are respectively caused by the cooling events during the Holocene “New High Temperature Period” and the sudden and sudden temperature drops Due. This is the first direct evidence obtained in the continuous sedimentary records of the enclosed lakes in arid areas in China about the events of temperature drop five thousand years ago and the sudden changes of the climate of the “new fairy wood” in the carbon isotope record.