关键词: 泥河湾盆地, 末次间冰期, 氧碳同位素, 湖相叠层石

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