Global Changes and Sedimentation on Continental Shelf

Based on the systematic analysis and study made recently of several sedimentarv core, and high resulu-tion geophysical records from the Yclluw Sea Shelf the writer believes that the global-change view must be fakm to carry、oul comprehensive unaly-,is m;d }innpari、uns in the study of sedimentary characteristics ofChiua Shelf. In the later stage of Late Pleistovene, the palaeoenvironmeat of China Shelf was different fromboth North America in which Laureatide Ive Sheet developed and Europe pith Scandinavia Ice Sheet oc-cured. Instead of ice sheet, large range of desert and loess distribution area (including most area of China's shelf) occurred in the Asian Continent. At the end of the last glavial period, the ice sheets in NorthAmerica and Europe Continent began to meit providing the North.American shelf and Europe shelf withsufticienl. wWer sources. Local crust oscillations further enhanced the washing dower of rivers. When the con-trnenla lce sheets melted over, the tivers passing or cntering the continental attelf lost ther runoff After the transgression of the Holocene, ntaw trace, of buried palaeorhanncls have nattarally bean left over on thecontinental sheaf ar.das As the sediment :ry environment of ('tuna C ontinental Shelf wts characterized by dryand cold, the chill` was not only bare,l and without the protection of ice sheet but also eroded by stormy inthe most prevailing of the ice age. Therefore, eolation ivas the basic effect on the China Shelf area in the iat-er stage of late Yleistoccne. As known up to now, major sedimentary types of the shelf desertization are(1) long. seale," tolation surfacc. (2) mixing accumulation of large area,(3) sedimentary structure- ofreposvanglc type and (4) typical sediments of buried sand-duets.