摘要
利用泥河湾盆地井儿洼剖面孢粉、粒度、碳酸盐含量、介形类壳体的δ18O及δ13C等多种环境代用指标,对泥河湾盆地47～25kaBP期间的古气候环境特征进行了探讨。结果表明,47～39kaBP期间,植被生长稀疏,降水较少,气候冷干。39～30kaBP期间,森林植被发育,入湖的粗颗粒物质增多,表明降水较多。同时介形类的大量繁殖造成碳酸盐含量的显著增高,以及介形类壳体δ18O和δ13C相对偏负,说明当时湖水的水热组合适宜,气候总体暖湿。自30kaBP开始,气候逐步恶化;25kaBP左右,井儿洼剖面沉积中断,气候转为冷干。总体而言,39～30kaBP期间,泥河湾盆地的气候暖湿,其暖湿的气候特征与青藏高原和西北地区的气候具有较好的一致性。
Paleoenvironmental and paleoclimatic changes of the Nihewan Basin between 47 and 25 ka BP was analyzed using multi-proxies such as pollen,grain size,carbonate,and δ18O and δ13C of ostracode shells from the Jing＇erwa section of Nihewan Basin.The results show that the episode between 47 and 39 ka BP saw sparse vegetation cover and low precipitation,which suggests cold and dry climate.During the period between 47 and 39 ka BP,abundant forest vegetation and increasing amount of coarse sediment into the lake indicate that the precipitation was high at that time.Meanwhile,the mass reproduction of ostracode caused increasing content of carbonate and relatively negativeδ18O and δ13C values of ostracode shells,suggesting that lake water was warm with low salinity.The climate was wet and warm.The climate began to deteriorate since 30 ka BP.Lacustrine sedimentation terminated in 25 ka BP,which is probably attributed to cold and dry climate.In a word,the climate was warm and wet between 39 and 30 ka BP,which is generally consistent with the record from the Tibet Plateau and the Northwestern China.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2010年第7期939-946,共8页
Acta Geologica Sinica
基金
中国地质科学院地质研究所基础科研业务费项目(编号J0718,J1001)
国家自然科学基金(编号40572100)资助的成果
关键词
泥河湾盆地
井儿洼剖面
古气候环境
Nihewan Basin
Jingerwa section
Paleoenvironment and paleoclimate
