渤海LZK06孔25万年沉积物粒度特征及沉积环境意义  

Grain-Size Characteristics and Its Environmental Significance of Sediments From Core LZK06 in the North Bohai Coast During the Last 250 ka

作　　者：王忱沛 李琰[1,2,3] 商志文 姜兴钰[4] 李建芬[4] 胡克[1] 王宏[4] WANG Chen-pei;LI Yan;SHANG Zhi-wen;JIANG Xing-yu;LI Jian-fen;HU Ke;WANG Hong(School of Ocean Sciences, China University of Geosciences, Beijing 100083, China;Leibniz Institute for Applied Geophysics, Hanover 30655, Germany;Hainan Key Laboratory of Marine Geological Resources and Environment, Haikou 570206, China;Tianjin Geological Survey Centre, CGS, Tianjin 300170, China)

机构地区：[1]中国地质大学(北京)海洋学院,北京100083 [2]德国莱布尼兹应用地球物理研究所,德国汉诺威30655 [3]海南省海洋地质资源与环境重点实验室,海南海口570206 [4]中国地质调查局天津地质调查中心,天津300170

出　　处：《海洋科学进展》2022年第1期66-78,共13页Advances in Marine Science

基　　金：国家自然科学基金项目——渤海海岸晚更新世海侵事件的长石光释光年代学研究(41907376);北京市自然科学基金项目——华北平原东部全新世海陆相沉积年代学与古环境对比研究(8204070);教育部中央高校基本科研业务费启动项目——海岸带—浅海沉积物光释光年龄的粒度效应研究(2652018064)。

摘　　要：对渤海北岸大凌河冲积平原的LZK06孔上部60 m沉积物开展了粒度测试,分析了粒度特征变化规律,探讨了控制粒度特征变化的因素及其对环境演化的指示。结果显示,LZK06孔沉积物以下部陆相沉积和上部海陆交互相沉积为特点。LZK06孔沉积物粒度整体较粗,指示了较强的沉积水动力。整体上海相沉积物粒度略粗于下伏陆相沉积物。地层年代学结果表明,LZK06孔上部60 m记录了渤海北岸25万年来经历了3次主要的海退—海侵过程。影响钻孔沉积物粒度特征变化的主要因素可能是古气候变化背景下的大凌河沉积水动力强度和携沙量的变化。在高海面时期,潮汐和波浪对沉积物粒度起到后期改造作用。This study measured grain-size for the sediments collected from upper 60 m of core LZK06 in the Dalinghe alluvial plain,the North Bohai Coast,described the change of grain-size characteristics,and discussed the driving factors for variations of grain size and their response to environmental evolution.The results show that the sediments are characterized as terrestrial-marine interbedded deposits in the upper 60 m of the core LZK06.The grain-size is overall coarse,indicating the strong hydrodynamics.Grain-size of marine sediments are generally coarser than those in the underlying terrestrial stratum.The characteristics of sediments,combined with the chronological framework,reflect that the region has experienced three transgression-regression cycles in the North Bohai Coast during the last 250 ka.The dominant factor of sediment grain-size is likely to be variation of the hydrodynamic and sediment concentration of the Dalinghe River under the background of paleoclimate evolution.Currents and waves reworked on the grain-size distribution during transgression period.

关 键 词：粒度 敏感组分 沉积环境 古环境变化 渤海 

分 类 号：P736[天文地球—海洋地质]