晚更新世末期南海北部陆架的古地理探讨

根据地球物理综合调查,沉积物的粒度、矿物成分、石英砂粒扫描电镜分析,14T测年,以及微体古生物等成果,表明南海北部外陆架地区在更新世末期,冬半年气候干寒,东北风强劲,风沙活动强烈,砂丘广布,为干寒多风沙的自然环境。

PAPAEOGEOGRAPHIC STUDY IN THE CONTINENTAL SHELF OF THE NORTHERN SOUTH CHINA SEA DURING THE LAST STAGE OF THE LATE PLEISTOCENE

According to the synthetical investigations in geology and geophysics, the results, obtained from the analysis of particle sizes of sediments and mineral composition, quartz grain analysis by scanning electorn microscope,dating 14C and nannofossils,show that: 1. During the last glaciation, most parts of the continental shelf area in the northern South China Sea were land, the climate was cold and arid in the winter. Northeast monsoocn wind prevails during that period. Sand were blown strongly by winds in the continental shelf area and sand dunes were widely distributed. 2. The micro-geomorphological occurrences such as remaining sands,seafloor sand dunes and sand ribbons,were mainly the wind sand and palaeo-sand dunes formed during the low sea level period in the last stage of the Pleistocene. They also were remoulded by the dynamic forces of the modern sea water.