THE CHANGES OF CLIMATE IN NORTH CHINA SINCE THE LATE GLACIAL AGE OF PLEISTOCENE
Zhou Tingru,Zhang Lansheng and Li Huazhang
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.