尕海地区晚冰期以来沉积记录的气候环境演变

CLIMATIC-ENVIRONMENTAL EVOLUTION IN GAHAI LAKE AREA SINCE THE LATE GLACIAL PERIOD FROM LOSS-ON-IGNITION

摘要: 通过对尕海沉积物烧失量和碳酸盐含量以及岩性变化分析,重建了尕海地区晚冰期以来的气候环境演变。结果显示:烧失量及碳酸盐含量指标可以较好地反映晚冰期以来的气候变化,晚冰期的阿勒罗德暖期和新仙女木事件有较好的反映。全新世则可划分为早全新世的不稳定期,年代为11 150~8 240 cal.aBP,中全新世较为暖湿期,年代为8 240~3 200 cal.aBP,晚全新世干冷期,年代为3 200 cal.aBP至今。并发现1 550~1 440 cal.aBP存在一暖湿事件。

Abstract: Based on analyses of Loss-on-Ignition (LOI), carbonate content and sediment characteristics, the authors reconstruct the climatic and environmental evolution of the Gahai Lake area since the Late Glacial period. The results cover the Aller d period (between 12 710 and 12 380 cal.aBP), the Younger Dryas period (between 12 380 and 11 360 cal.aBP), and the Holocene. The Holocene can be divided into three periods:the early Holocene (11 360~8 240 cal.aBP), which was dry but unstable and featured rising temperatures; the mid-Holocene (8 240~3 200 cal.aBP), which was warm and wet in early period and cool and dry in late period; and the late Holocene (since 3 200 cal.aBP), which was cold and dry in early period and relativele warm and dry in late period. Results also show a warm-wet event around 1 500 cal.aBP.