GLOBAL DISTRIBUTION OF CARBONATE EOLIANITE IN THE WORLD AND IMPLICATION FOR XISHA ISIANDS

Carbonate eolianite forms distinctive coastal landforms on many mid-latitude continents and islands. The global distribution of carbonate eolianite coincides well with the global climate zones, and it is usually located in Mediterranean climate, tropical grassland and desert zones, where the alternation of atmosphere and wind belt dominates. In principle, carbonate eolianite should occur without time limitation, but most of them formed in Pleistocene. The development of carbonate eolianite is mainly influenced by climate, and limited by coastal landform and carbonate productivity. It has close connection with the fluctuation of global sea level. And most of the Pleistocene carbonate eolianite was formed during high sea level stages. The carbonate eolianite on Shidao Island of Xisha Islands is one of the few examples which developed in tropical-marine-monsoon climate zone. The carbonate eolianite on Shidao Island is the product of the East Asian monsoon, which may reflect relative arid climatic conditions during Late Pleistocene Epoch. The alternation of carbonate eolianite and paleosol may reflect the fluctuation of sea level or climate changes. So, the deep study of mechanics of carbonate eolianite on Shidao Island is of great significance to the researches of East Asian monsoon and paleo-oceanography in the southwest of South China Sea.