天津三河岛潮间带137Cs与210Pb的分布及现代沉积过程

137Cs and 210Pb distribution and modern sedimentation in the north and south intertidal zones of Sanhe Island, Tianjin, China

位于永定新河、潮白新河与蓟运河汇流处的三河岛是天津市列入国家海岛名录的唯一岛屿,其独特的地理位置记录了现代海、陆交互作用的变化过程。取自该岛南、北两侧泥质潮间带的2组现代沉积物样柱,揭示137Cs和210Pbexc的最大检出深度分别达到90～123cm和140～210cm,属于渤海湾西岸泥质海岸带现代沉积最为活跃的“面向开放海湾亚带”。

Sanhedao Island, located in the confluence of the Yongding New River-Chaobai New River and Jiyun River, is the only island included in the List of Islands of the People＇s Repubhc of China, and thus its specific geographic position records the process of modem land and sea interaction. Two columns of samples from modem sediments taken from the muddy intertidal zones at the north and south sides of the island reveal the maximum depths of 90-123 cm for 137Cs and 140- 210 cm for 210Pbexc respectively. So the area belongs to a ＂subzone facing the open bay＂ where modem sediments are the most active in the muddy coastal zone on the west coast of the Bohai Bay.