晚更新世以来黄渤海海侵与黄土高原地貌区域分异

MARINE TRANSGRESSIONS IN THE HUANGHAI BOHAI SEA BASIN AND GEOMORPHOROLOGICAL EVOLUTION IN THE LOESS PLATEAU SINCE LATE PLEISTONCENE

晚更新世以来，黄渤海盆地沉降速率较大，发生了三次大规模的海侵，黄渤海的出现加强了东亚夏季风和黑潮暖流对黄土高原东部地区气候的影响；东部地区晚更新世温湿期的气候较早中更新世为湿润，降水特别是汛期降水较多，侵蚀强烈。和黄渤海三次大规模海侵相对应，东部地区晚更新世以来有三次强侵蚀期，中更新世末的统一黄土高原被侵蚀分异为梁峁区和塬区。东部地区的东北部陕北北部、晋西北一带，由于黄土粒度粗，抗蚀性差，侵蚀暴雨多，侵蚀最为强烈，形成了现今的梁峁地貌；南、西、西北部，由于黄土粒度细，抗蚀性较好，或侵蚀暴雨少，侵蚀相对微弱，形成现今的塬。

Three major marine transgressions have occurred in the Huanghai Bohai Sea Basin since late pleistoncene because of the higher subsidence rates of the basin. The appearance of the Huanghai Bohai Sea strengthed the influences of summer moonson and Kuro shio Current on the climate of the East Loess Plateau. Rainfall was higher and erosion was severer in late pleistoncene and holocene than those in early middle pleistoncene, during the interglacial periods in the East Loess Plateau. Three severe erosion stages in the plateau were correlated to the three major marine transgressions in the sea. The entire flat Loess Plateau at the end of middle pleistoncene has disintergrated into Yuan (flat plateau dedected by gullies) and Liangmao (hilly plateau dessected by gullies) by severe water erosion since late pleistoncene