淮河上游桐柏县卢庄SWD粒度端元分析  

SWD end member analysis of grain-size of Luzhuang Village in Tongbai County in the upper Huaihe River

作　　者：王兆夺 黄春长 庞奖励 周亚利 查小春 

机构地区：[1]陕西师范大学地理科学与旅游学院地理学国家级实验教学示范中心,西安710119

出　　处：《兰州大学学报（自然科学版）》2017年第6期720-726,共7页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(41771110;41601020);中央高校基本科研业务费专项资金项目(No.GK.201704013)

摘　　要：通过沿着淮河上游详细的野外调查,在桐柏县卢庄村附近淮河北岸发现了全新世黄土-古土壤剖面夹有古洪水滞流沉积层.对剖面进行详细观察和分层采样,在实验室内进行粒度分析.对所获得的分析数据,应用端元分析模型分离出4个端元,以识别沉积动力环境,鉴别特大洪水事件的沉积学记录.不同的地层单元具有不同的端元组合特征,各个端元皆能够很好地指示沉积动力环境和物源特征.其中端元1可能指示了沉积物在沉积后受到次生风化作用强度特征;端元2可能指示了生物成壤过程和农业耕作活动等对沉积物的后期影响;端元3可能代表了沉积过程中受到风成动力作用的特征;端元4比较明确地指示了特定物源条件下流水动力环境.将端元分析与野外沉积学宏观特征相结合,在此全新世地层剖面鉴别出6次特大古洪水事件.通过沉积物粒度端元分析,表明该模型在鉴别沉积动力环境和物源特征方面具有很好的作用,对于从河谷黄土古土壤剖面鉴别古洪水滞流沉积物具有很好的效果.Through a detailed field investigations along the upper Huaihe River, palaeoflood slack water deposits （SWD） were identified in the loess-soil profile on the north bank of the river near Luzhuang Village in Tongbai County. Detailed observations and stratified sampling for the profile were done and an analysis of the grain size was conducted in the laboratory. Four end members （EMs） were extracted by end member analysis, to identify the sedimentary dynamic environment and the sedimentology records of floods events. The result showed that different stratigraphic units had different combination characteristics of end member and each EM could indicate the sediment environment or provenance. EM 1 might indicate the weathering power for sediment. EM2 might indicate the disturbance affect after deposit by the biological pedogenetic process and artificial cultivation activity. EM3 might indicate the aeolian sedimentary characteristic. EM4 might indicate the characteristic of the hydrodynamic environment. Combining the result of EM analysis and the characteristic of field observation, six times extraordinary paleoloflood events were identified in the Holocene profile. A very good result was achieved through the EM analysis of grain size in the sedimentary environment and source characteristics. This study may have a very good application in identifying SWD from a loess-paleaosol profile.

关 键 词：黄土-古土壤 古洪水滞流沉积物 粒度 端元分析 淮河 

分 类 号：TU18[建筑科学—建筑理论]