Acta Scientiarum Naturalium Universitatis Pekinensis

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The Records of (δ)18O and (δ)13C for Climate Changes in Nihewan Basin during the Last Interglacial

XIA Zhengkai1, HAN Junqing1, JIN Deqin2, ZHOU Xihuang2   

  1. 1Department of Urban and Environmental Science, Peking University.Beijing, 100871; 2College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871
  • Received:1997-01-28 Online:1998-01-20 Published:1998-01-20

泥河湾盆地末次间冰期气候变化的氧碳同位素记录

夏正楷1, 韩军青1, 金德秋2, 周锡煌2   

  1. 1北京大学城市与环境学系,北京,100871;2北京大学化学与分子工程学院,北京,100871

Abstract: According to the variation of stable isotopic composition of carbonate in lacustrine deposited in Hutouliang, Nihewan Basin, the section can be subdivided into four oxygen-carbon-isotope stages. They are as follows from top downwards: (1) 0.00-1.85m, which gave lower value of oxygen and carbon isotope. The (δ)18O value of 4 samples ranges from -7.16 to -7.88, (δ)18O(avg)=-7.53; the (δ)13C value ranges from -3.40 to -5.57, (δ)13C(avg)=-4.30. (2) 1.85-7.00m, which gave higher value of oxygen and carbon isotope. The (δ)18O value of 12 samples ranges from 0.46 to -5.52, (δ)18O(avg)=-2.59; the (δ)13C value ranges from 0.23 to -3.66, (δ)13C(avg)=-1.17. (3) 7.00-10.10m, which gave lower value of oxygen and carbon isotope. The (δ)18O value of 4 samples ranges from -6.97 to -9.39, (δ)18O(avg)=-8.50; the (δ)13C value ranges from -2.68 to -6.85, (δ)13C(avg)=-4.04. (4)10.10-14.87m, which gave higher value of oxygen and carb on isotope. The (δ)18O value of 11 samples ranges from 0.57 to 6.36, (δ)18O(avg)=-2.94; the (δ)13C values ranges from 3.43 to -3.52, (δ)13C(avg)=-0.73. Generally, the values of (δ)18O and (δ)13C of carbonate in lacustrite sediment have a positive correlation with that of the water saltness, the saltness has a positive correlation with evaporativity, and the evaporativity has a positive correlation with temperature and a negative correlation with humidity. So the high value of oxygen and carbon isotope ((δ)18O and (δ)13C) in Nihewan represents a relatively hot and dry weather while the low value of which represents a rather cool and wet weather. The variation of oxygen and carbon isotopic value among the section indicates the alternation between hot-dry and cool-wet climate during the last interglacial period.

Key words: (δ)18O, (δ)13C, Nihewan Basin, last interglacial period

摘要: 黄土-古土壤序列的研究表明,我国东部地区第四纪气候演变的总规律是干冷与湿暖的交替。但是,气候的变化是一个复杂的过程,在不同时间和地点,气候的干、湿和冷、暖变化可能会出现不同的组合。根据泥河湾盆地晚更新世湖泊沉积物中所含碳酸盐的氧碳同位素研究,认为在末次间冰期(距今13~7万年),该区气候以干暖与湿冷的交替为主要特征。这一发现将有助于加深对我国东部第四纪气候变化规律的认识。

关键词: 泥河湾盆地, 末次间冰期, 氧碳同位素, 湖相叠层石

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