辽宁省海岸带主要河口区一万年来沉积速率及海平面波动情况

采用钻探手段,通过14C、OSL测年,利用4孔岩心,计算了辽宁省海岸带主要河口区一万年来沉积速率,并分析了海平面波动情况.研究表明,辽宁海岸带长期平均的河口海岸区的沉积速率较低.其中,辽东半岛东北部黄海海岸带鸭绿江平原全新世早期处于剥蚀环境,大洋河平原全新世平均沉积速率为1.4 mm/a,辽东湾北部下辽河平原全新世平均沉积速率为1.52 mm/a,辽西海岸带大凌河冲积扇全新世平均沉积速率为1.87mm/a.全新世Ⅰ海相层或海陆过渡相层总体上表现为一次海侵,与下辽河平原区盘山海侵相对应,但各地段海平面波动情况不尽一致.

DEPOSITION RATE AND SEA-LEVEL FLUCTUATIONS OF THE MAJOR ESTUARINE AREAS IN THE COASTAL ZONE OF LIAONING DURING TEN THOUSAND YEARS

Based on the 14C and OSL dating for cores from four drill holes in the major estuarine areas of the Liaoning coastal zone,the deposition rates of the recent 10 000 years are calculated,with analysis on the fluctuation of the sea level.It is revealed that the average deposition rate of the estuaries is low during a long term.Among them,the Yalu River Plain in the Yellow Sea coast in northeast Liaodong peninsula experienced an erosion environment in early Holocene.The average deposition rate of Yanghe Plain is 1.4 mm/a in Holocene; that of the Lower Liaohe Plain in the north of Liaodong Bay is 1.52 mm/a; while that of the Dalinghe alluvial fan in the Western Liaoning coast,1.87 mm/a.The Holocene marine bed I or the marine-continental transitional bed represents a process of marine transgression,which corresponds to the Panshan marine transgression in Lower Liaohe Plain.However,the sea-level fluctuations vary in different areas.