中國大陸的第四紀冰河

Abstract

Although the Quaternary is the most recent geological reriod, it isstill divided into the two different Chronology of pleistocene and Holoceneaccording to the change of temperatures. The former had not only more than twomillion years but also within the important ages of the cilmate fluctuationwhereas the latter is only about ten thousand years in the post-glacial period.During pleistocene the clinate of Chinese mainland was rather similar to theclimate of the whole earth's surface of that tine, and therefore average annualtemperature was most probably about 5 ℃ to 10 ℃ lower than at present, and itwas very dry, cold, and less rainfall.As a result, the climaet of the Tibeta Plateau and other peaks of mountainsbecame also more and more cold and dry owing to both intense tectonic movementand the strong uplift of the plateau so that the development of some wide andlong moumtain glaciers have been seriously formed after the middle ofpleistocene, and it occupied an area 15 times that of Holoce or today as well asother high peaks east or north of the Tibetan plateau. Though the glacier areaof the plateau was very spacious in the hinterland of chinese mainland, but nogreat ice sheet was formed during that time, and some the longest valleyglaciers reached 50-100 Km in length.In the main, the spectacur elevation, topography, and climate of the Tibetanplateau exert grat influences on the development of mauntain glaciers, and sothe present glacierized area on the plateau reaches about 46,640 Km ??, just 83%of the total glacierized area in Chinese mainland. In other part of Chinesemainland, Tien Shan has its long and wide valley glacietrs on the west end andcentral areas at an elevation of over 4,000m above sea-level.According to general statistics of the existing glaciers in the plateau andmountainous area in west China-mainland. It has a total area of 56,500Km ??,about one half of the total area of mou