QUATERNARY ENVIRONMENT ANALYZING IN CHINA WITH THEMATIC MAPPING

It is necessary and possible to provide some more clear images of Quaternary Paleo-environment in China based on newly researches in this field. Thematic maps of three special stages, that is, Holocene (6ka), Last Glacial Maximum (18ka), and Late Interglacial Stages (120ka) have been mapped by computer-aided mapping techniques. Natural environment elements such as glaciers, frozen earth, deserts, bio-climate zones, etc., have been considered as basic layers to constitute the maps. Analysis of these maps in terms of spatio-temporal relations of different environment elements in a single map and between maps shows that the formation and transformation process of Paleo- East Asia Monsoon impact greatly on spatial and temporal distribution on Quaternary deposits and other environment elements as well. Statistics shows that glaciers areas in the following four different stages, present time, Holocene (6ka), the Last Glacial Maximum (18ka), and the Late Interglacial Stage (120ka) are 59600km2, 50300km2, 296100km2, and 50100km2, while the corresponding desert area are 1533000 km2, 800400 km2, 2268600 km2, and 780300 km2 respectively. The southmost spots of bio-climate between cold temperate zone and temperate zone, temperate zone and subtropical zone£¬subtropical zone and tropical zone in eastern monsoon area in China are 49.7N, 41.7N, 23.2N in Holocene (6ka), and 51.02N,41.8N,23.7N in Late Interglacial Stage (120ka). And 38.8N, 22.4N were southmost spots of bio-climate between cold temperate zone and temperate zone, whereas subtropical zone and tropical zone disappeared in mainland and shifted to South China Sea in Last Glacial Maximum (18ka), which reflect the large scale movements of the bio-climate zone with global climate and environment changes. Furthermore, backgrounds and factors of these paleo-environment changes is put forwards.