渤海湾老狼坨子海岸带^(14)C、^(137)Cs、^(210)Pb测年与现代沉积速率的加速趋势

^(14)C, ^(137)Cs and ^(210)Pb dating and accelerated tendency of the present sedimentation rate along the Laolangtuozi coast of the Bohai Bay

通过对渤海湾西岸L剖面中同一关键层的碳酸钙和原生腹足类壳体的14C测年对比研究,确定了晚全新世约2800calBP的层位及沉积速率0.045cm/a;8个样柱的137Cs和210Pbexc强度、蓄积量揭示了距今约120年来堤后盐沼的平均沉积速率约为0.35cm/a,而面向开放海湾的潮坪上部则达到约2～3cm/a。研究区近1个世纪以来沉积速率的加速趋势,是渤海湾西岸泥质海岸带的特征之一。

C dating comparative study of the calcium carbonate and insitu gastropods in the same key layer in transect L on the west coast of the Bohai Bay has determined the late Holocene ～2800 cal BP horizon and the sedimentation rate of 0.045 cm/a. The 210Pb and 137Cs data and inventories of eight columns, combined with the radiocarbon ages, reveal that the average sedimentation rate in the last ～120 years is ～0.35cm/a for the back-marsh and ～2-3cm/yr for the upper part of the open intertidal flat. The acceleration trend of the sedimentation rate in the study area over nearly a century is one of the features of the muddy coastal zone of the Bohai Bay. has existed in the transect L in the back-marsh and intertidal area in Laolangtuozi, Bohai Bay.