【摘要】 <正> 研究更新世最后冰期以来陆上大尺度气候变迁,在欧洲和北美均以大陆冰盖后退过程中各阶段所遗留的各种遗迹,孢粉分析所揭示的、随冰盖后退而发生的植被带的更替以及反映冰盖消长的全球性海面升降为主要标志。由于大陆性气候的影响,我国东部在最后冰期不存在大面积冰盖。但由于冬长、严寒,华北北部和东北广大地区,晚更新世冰期的冰缘现象普遍发育,近年来不断有所发现;地势或纬度较高的地方,甚至留下了全新世寒冷时期的融冻遗迹。本文根据在华北实地考察所发现的冰缘现象遗迹,与之相应的孢粉分析所反映的植被变化以及某些地点所见到的海平面变动,讨论更新世最后冰期以来华北地区的气候变迁概况。更多还原

【Abstract】 Periglacial phenomena such as involution and ice-wedge are discovered by the authors in the deposites at Hu-Tou-Lian(40°N, 910M), Yang-yuan County, Hebei Province and Dai-Hai Lake basin(40°N, 1240M), Inner-Mongolia. By C-14 dating, the former belongs to the Late Pleistocene (B. P. 11, 000—27, 000) (Fig. 1, 2, 3) and the later Holocene(Fig. 7, 8). The results of pollen analysis for these beds are shown in fig. 9, 10(Dai-Hai) and the table(Hu-Tou-Liang) in page78. In the coastal county Fu-Shan and the tombolo Zhi-Fu, Shandong Province, the authors found that marine sediments deposited on the position that 14—15 metres higher above the present sealevel. C-14 dating of the shells in these beds show that they were B. P. 5420(Fu-Shan) and B. P. 2540(Zhi-Fu) seperately. In accordance with these evidences, the authors conclude that the Würm Glacial Age in North China could be derided into two stages by the relatively less-cold period B. P. 40, 000—50,000, and two cold substages could be recognized in the Late Würm Stage. In the coldest substage, average annual temperature was 10°—11℃ lower than present. There are four cold periods in the Holocene in North China, occured in B. P. 11,000—8,500, B. P. 3,000± and A. D. 1,550—1,900; in the former three periods annual temperature were 3℃ lower than present(Fig. 13, the fourth period not shown in the figure). These process of climatic variation are comparable with that in the midlatitudinal regions of Europe and North America.更多还原