四万年来青藏高原的气候变迁

PALAEOCLIMATIC EVOLUTION WITHIN THE QINGHAIXIZANG (TIBET) PLATEAU IN THE LAST 40 000 YEARS

内陆湖泊,特别是那些大型的淡水湖和盐湖,在漫长的演变历史长河中,对气候环境的反映是相当敏感的。巨厚的沉积物,记录了古气候变迁的丰富信息。盐湖的研究表明,40000年来的重大气候事件,在世界屋脊——青藏高原内部同样有明显的反映。

The climatic evolution in Quaternary is an attractive scientific subject, especially the palaeoclimatic change over the Qinghai-Xizang (Tibet) Plateau has drawn the attention of scholars at home and abroad. The plateau which is covered by the vast arid-semiarid region developes many salt lakes. These salt lakes contain affluent information about palaeoclimatic change and is of importance in the study of the arid-semiarid region. In the past years, we have collected some data of palaeoclimatic change through the study of salt lakes in the plateau. Basing on the studies of Qinghai Lake, Qarhan Salt Lake in Qaidam Basin and Zhacangchaka Lake in northern Xizang, the authors give a climatic change sequence in the last 40 000 years as follows: 38 000—25 000 a B. P. wet 25 000—10 000 a B. P. cold-dry 10 000—7 000 a B. P. warm-dry 7 000—3 600 a B. P. wet-tepid (climate optimum) 3 600—1 500 a B. P. cool and tepid alternating 1 500 a B. P.—present similar to today The results suggest that the influential global climatic events in the last 40 000 years also reflected over the Qinghai-Xizang Plateau, even though they were not completely synchronous sometimes.