川北若尔盖高原红原泥炭剖面孢粉记录的晚冰期以来古气候古环境的演变

Paleoclimatic and paleoenvironmental evolution since the late glacial epoch as recorded by sporopollen from the Hongyuan peat section on the Zoigê Plateau, northern Sichuan, China

利用14C测年及孢粉分析方法对位于若尔盖高原的红原泥炭剖面进行了系统研究,重建了若尔盖地区晚冰期以来古环境的演化历史,并识别在此期间发生的主要气候事件。结果表明:该区晚冰期的气候特点为冷偏干或凉偏干,冷暖波动频繁。其中,14.1～13.4、12.4～12.0和10.5～10.0kaBP之间的冷阶段分别对应于OldestDryas、OlderDryas及YoungerDryas事件;发生于12.6～12.4和12.0～10.5kaBP左右的暖阶段分别对应于Bolling及Allerod暖期。YoungerDryas事件之后,气候总体以温湿为主要特征,8.9～8.7和6.1～5.8kaBP之间的明显降温为全新世期间的2次冷事件。孢粉记录所反映的若尔盖地区晚冰期以来的气候演化与全球气候变化具有较好的可比性。

A 7.95 m thick peat section at Hongyuan on the southern Zoige Plateau was systematically studied using the ^14C method and sporopollen analysis, the paleoenvironmental history since the late glacial epoch in the Zoige area was reconstructed and the main paleoclimatic events occurring in this period were identified. The late glacial epoch in the area witnessed a cold-slightly dry or cool-slightly dry climate and repeated cold-warm climatic oscillations. The cold phases in the 14.1-13.4, 12.4-12.0 and 10.5-10.0 ka intervals correspond to the Oldest Dryas, Older Dryas and Younger Dryas events respectively, and the warm phases in the 12.6-12.4 and 12.0-10.5 ka intervals correspond to the BoUing and Allerod warm events respectively. The climate after Younger Dryas was mainly warm and moist, and the significant temperature lowering in the 8.9-8.7 and 6.1-5.8 ka intervals marked two cold events in the Holocene. The climatic evolution since the late glacial epoch in the Zoige area reflected by sporopollen records may be well correlated with the global climate change.