渤海南部早-中更新统湖相沉积的粒度特征及其对沉积环境的指示  

Grain-size Characteristics of Early-Middle Pleistocene Lacustrine Sediments and Their Indication of Sedimentary Environment in the Southern Bohai Sea

作　　者：吕文哲[1,2] 易亮[3,4] 付腾飞[1,2] 陈广泉[1,2] 徐兴永[1,2] 于洪军 LV Wen-zhe YI Liang FU Teng-fei CHEN Guang-quan XU Xing-yong YU Hong-jun(Key Laboratory of Marine Sedimentology and Environmental Geology, The First Institute of Oceanography, SOA , Qingdao 266061, China Laboratory for Marine Geology ,Qingdao National Laboratory for Marine Science and Technology ,Qingdao 266061 ,China School of Ocean and Earth Science, Tongji University, Shanghai 200092, China State Key Laboratory of Marine Geology, Shanghai 200092, China National Deep Sea Center, Qingdao 266237 ,China)

机构地区：[1]国家海洋局第一海洋研究所海洋沉积与环境地质重点实验室,山东青岛266061 [2]青岛海洋科学与技术国家实验室海洋地质过程与环境功能实验室,山东青岛266061 [3]同济大学海洋与地球科学学院,上海200092 [4]海洋地质国家重点实验室,上海200092 [5]国家深海基地管理中心,山东青岛266237

出　　处：《海岸工程》2017年第1期34-42,共9页Coastal Engineering

基　　金：国家重点研发计划--沿海地区海水入侵现状调查评价(2016YFC0402801);国家海洋局海域管理技术重点实验室开放基金--基于Ra同位素的莱州湾南岸海水入侵灾害示踪(201503);国家自然科学基金项目--莱州湾南部晚新生代海-陆相沉积的磁性地层学研究(41402153);海洋公益性行业科研专项--典型海岛生态脆弱性评估及综合调控技术研究与示范(2015418012)

摘　　要：通过对莱州湾南岸Lz908孔下部47m沉积物的粒度分析,揭示了该地区沉积物的粒度特征:平均粒径介于3.2Φ~7.4Φ,大部分为黏土质粉砂,少部分为砂质粉砂,亦含有少量粉砂质砂;分选系数介于1.1~2.5,分选较差;偏度绝大多数介于0.7~2.4,表现为正偏和极正偏;峰度介于1.9~3.4,表现为平坦和正态。通过粒级组成、粒度象特征、粒度结构散点图等的综合分析,表明:钻孔下部沉积物与上部沉积物相比,指示了相对低能稳定的水动力环境;莱州湾南岸地区在早-中更新统处于浅湖相与深湖相交替存在的沉积环境。因此,本文认为对渤海莱州湾南岸地区沉积物粒度特征的研究可以有效的判断沉积环境,提取古环境信息,是沉积环境的重要替代指标。Grain-size analysis of the lower 47 m sediments in Borehole Lz908 drilled at the southern coast of the Laizhou Bay reveals that the mean grain diameter of the sediments ranges from 3.2 Φ to 7.4 Φ,indicating that they are mainly composed of clayey silt,followed by a small amount of sandy silt and silty sand.The sorting of the sediments is poor,with the sorting coefficient being 1.1~2.5.The skewness and the kurtosis of the sediments are mostly 0.7~2.4 and 1.9~3.4,respectively,showing a positive and/or very positive skewness and a flat and/or normal distribution,respectively.The comprehensive analyses of grain size compositions,grain-size C-M diagrams and grain-size structural scatter diagrams of the sediments indicate that compared with those in the upper part of the borehole,the sediments in the lower part of the borehole reflect a relatively lower-energy and more stable hydrodynamic environment,and that the southern coastal area of the Laizhou Bay was in a sedimentary environment in which the shallow and deep lacustrine facies were formed alternately in the Early-Middle Pleistocene.It is,therefore,considered that the grain size characteristics of the sediments in the southern coastal regions of the Laizhou Bay can be used effectively for determining the sedimentary environment and extracting the paleoenvironmental information,and could be the important proxies of sedimentary environment.

关 键 词：莱州湾南岸 粒度 沉积环境 河湖相 

分 类 号：P736.213[天文地球—海洋地质]