长江三角洲晚更新世第一硬土层研究进展  

An overview on the First Hard Soil Layer(FHSL)of the Late Pleistocene in the Yangtze River delta

作　　者：王辉[1] 郑祥民[1] 钱鹏[2] 吴超[1] 任少芳[1] 赵庆[1] WANG Hui;ZHENG Xiangmin;QIAN Peng;WU Chao;REN Shaofang;ZHAO Qing(Key Laboratory of Geographic Information Science of Ministry of Education,East China Normal University,Shanghai 200062;School of Geographical Sciences,Nantong University,Nantong 226000,Jiangsu)

机构地区：[1]华东师范大学,地理信息科学教育部重点实验室,上海200241 [2]南通大学地理科学学院,江苏南通226000

出　　处：《第四纪研究》2021年第6期1771-1780,共10页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:41871015)资助。

摘　　要：长江三角洲晚更新世晚期的第一硬土层是划分更新统与全新统地层界面的标志层,也是上海中、高层建筑物的主要桩基持力层,具有第四纪科学研究和工程地质应用价值。由于缺乏明显指相意义的沉积标志和古生物化石等特征,对于第一硬土层的成因、物源和次生演化等问题,各家学者的观点相差甚远,至今没有达成共识。在讨论第一硬土层的沉积年代、沉积环境和沉积特征的基础上,评析了硬土层研究中的三大争论,即成因的"水成与风成"之争,物源的"近源与远源"之争和次生演化过程之争,认为硬土层经历了复杂的冷暖干湿变化和海侵海退旋回,可划分为早期冷干环境的沉积阶段、中期全新世海侵之前暖湿环境的风化和成土阶段、后期海侵及海退之后的掩埋改造阶段等3个时期。解决第一硬土层争论的途径是建立高精度连续年代序列标尺,运用地层追踪方法进行区域性标志地层的对比,在此基础上探索硬土层的形成与演化机制。The top strata of the Late Pleistocene Series in the Yangtze River Delta generally consist of hard clay,with a thickness up to 1~10 meters,which formed under dry-cold climate conditions during the Last Glacial Maximum,then transformed into hard clay through a long period of weathering leaching and diagenesis.The First Hard Soil Layer(FHSL)in the Late Pleistocene is an important marker bed for dividing the Holocene and Pleistocene Series,which also serves as the main bearing stratum of pile foundation for medium and high-rise buildings in Shanghai.However,the understanding on the formation reason,material source and secondary evolution of the FHSL are still controversial due to the lack of specific sedimentary marks and fossils.For example,the origin on the FHSL exists hydro-genesis and aeolian-genesis,provenance for the FHSL is proximal or distal,and the secondary evolution of the FHSL is also debated.The deposition and evolution of the hard soil layer experienced complex climate changes of cold warm dry wet and transgressive regression cycles,which can be divided into three stages:the deposition stage of early cold dry environment,the weathering and soil forming stage of warm wet environment before Holocene transgression in the middle stage,and the burial and transformation stage after transgressive regression in the later stage.To solve disputes on the FHSL,it is necessary to establish a continuous high-precision chronological scale,to trace maker bed regionally,and to study evolution processes and mechanism of hard soil layer.

关 键 词：第一硬土层 晚更新世 长江三角洲 

分 类 号：P534.631[天文地球—第四纪地质学] P53[天文地球—古生物学与地层学]