淮河支流汝河全新世古洪水沉积序列粒度指示的地表过程  

Surface Processes Indicated by Grain Size of Holocene Palaeoflood Sedimentary Sequences in the Ruhe,a Tributary of the Huaihe River

作　　者：王兆夺 黄春长 周亚利 陈莹璐 尚瑞清 查小春 庞奖励 WANG ZhaoDuo;HUANG ChunChang;ZHOU YaLi;CHEN YingLu;SHANG RuiQing;ZHA XiaoChun;PANG JiangLi(Geological Hazards Prevention Institute,Gansu Academy of Sciences,Lanzhou 730000,China;School of Geography and Tourism,Shaanxi Normal University,Xi'an 710016,China;State Key Laboratory of Estuarine and Coastal Studies,East China Normal University,Shanghai 200062,China)

机构地区：[1]甘肃省科学院地质自然灾害防治研究所,兰州730000 [2]陕西师范大学地理科学与旅游学院,西安710016 [3]华东师范大学河口海岸学国家重点实验室,上海200062

出　　处：《沉积学报》2024年第4期1268-1278,共11页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(42171092);甘肃省自然科学基金项目(23JRRA1660);甘肃省科学院人才基金项目(QD2023-04)。

摘　　要：【目的和方法】为了深入理解淮河流域全新世环境与地表过程演变,通过对淮河流域详细的野外调查,在汝河上游诸市乡段一级河流阶地前沿发现了夹有多层古洪水滞流沉积层的全新世黄土土壤沉积物地层剖面。对该剖面进行详细观察测量,地层划分和分层采样,在实验室进行多种指标分析研究。在前期沉积学性质研究和年代测定的基础上,应用端元分析方法进行粒度成分解析,深入分析古洪水沉积物序列的物源及其沉积学特征变化规律。【结果】采用非参数法从沉积序列中解析出具有不同物源和沉积动力学意义的4个端元组分。各土壤沉积物地层单元中除了现代洪水沉积层和河漫滩相细沙层外,其余层次都显示出多端元组分混合叠加的特点。【结论】结合野外宏观特征及其理化性质综合分析,可知其端元1组分代表西北季风沙尘暴远源风成沉积物及其风化成壤改造的产物,端元2组分代表了东北风吹扬黄泛平原松散沉积物沙尘暴的近源沉积物,端元3组分代表了河流洪水悬移质泥沙在高水位滞流环境条件下的沉积物,端元4组分为河流在河槽之内水动力作用下河漫滩冲积物。表明通过对全样粒度进行端元解析,能够更清晰地反映出汝河流域多元化的沉积动力特点。[Objective and Methods]For a profound understanding of the evolution of the Holocene environment and surface processes in the Huaihe River Basin.Through a detailed field investigation in the Huaihe River Basin,a Holocene loess soil stratigraphic profile with multiple layers of paleo-flood stagnant sediments was found at the front of the first-level river terrace in the Zhushixiang section of the upper reaches of the Ruhe River.The section was observed and measured in detail,stratigraphic division and stratified sampling were conducted,and various index analysis and research are performed in the laboratory.In this study,based on the previous study of sedimentological properties and dating,the end member(EM)analysis method was used to analyze the grain size components and further reveal the provenance of this palaeoflood sediment sequence and the change law of its sedimentary dynamic characteristics.[Results]From this sedimentary sequence,four EM components with different provenance and sedi⁃mentary significance were analyzed by the nonparametric method.With the exception of the modern flood sediment and fine sand layers of the floodplain facies,the other layers in each stratigraphic soil unit exhibited characteristics of mixing and superposition of multi-EM components.[Conclusions]Combined with the comprehensive analysis of the macroscopic characteristics and physical and chemical properties in the field,the EM 1 component were shown to represent the far distal source aeolian sediments of the northwest monsoon dust storm and the products of the weather⁃ing and soil transformation,and the EM 2 component represents the proximal sediment of the loose sediment sand⁃storm in the northeast wind blown Yellow River flood plain.The EM 3 components represented the sediments of the suspended sediment of the river flood in the high water level stagnation environment,and the EM 4 components were the floodplain water of the river in the channel Sediment under dynamic action.This shows that the end member analy⁃sis of th

关 键 词：黄土 古土壤 古洪水 粒度端元分析 全新世 淮河 

分 类 号：P534[天文地球—古生物学与地层学]