Initiation and evolution of coarse-grained deposits in the Late Quaternary Lake Chenghai source-to-sink system:From subaqueous colluvial apron(subaqueous fans)to Gilbert-type delta  

作　　者：Dao-Tao Dong Long-Wei Qiu Peng-Jie Ma Guo-Ding Yu Yu-Zhe Wang Shi-Bo Zhou Bao-Liang Yang He-Qing Huang Yong-Qiang Yang Xin Li 

机构地区：[1]School of Geosciences,China University of Petroleum(East China),Qingdao 266580,Shandong Province,China [2]SINOPEC Geophysical Research Institute,Nanjing 211103,Jiangsu Province,China [3]CCCC Second Highway Consultants Co.Ltd.,Wuhan 430056,Hubei Province,China

出　　处：《Journal of Palaeogeography》2022年第2期194-221,共28页古地理学报（英文版）

基　　金：the National Natural Science Foundation of China (Grant No. 42172115,41972099, 42102153);the China Postdoctoral Science Foundation (Grant No. 2021M693500);the National Major Science and Technology Projects of China(Grant No. 2017ZX05009-002, 2017ZX05072-002)。

摘　　要：Investigating the formation and evolution of coarse-grained deposits in modern lakes and the relevant controlling conditions is indispensable to the prediction of reservoir sandbodies, disaster prediction,and limnological research. The source-to-sink system of coarse-grained deposits in Lake Chenghai, a deep,scarped Late Quaternary lake, was investigated in this study based on 62 outcrops, Advanced Land Observing Satellite(ALOS) digital elevation model(DEM) data, and regional geological survey data. The findings include the following:(1) the source areas of coarse-grained deposits in Lake Chenghai were lithologically classified into carbonate source areas, basaltic source areas and siliciclastic source areas, and were geomorphically categorized as scarp type or confluence type. Subaqueous colluvial aprons have formed downstream of the carbonate source areas and scarp-type basaltic source areas, while Gilbert-type deltas have formed downstream of siliciclastic source areas and confluence-type basaltic source areas.(2) The formation and evolution of coarse-grained deposits are controlled by the sediment flux that evolves in synchrony with the geomorphic evolution of the source areas and the sink regimes. Scarps represent the initial landform of the source areas.Source material rolls off or slides down scarps or forms small-scale debris flows before entering the lake. The source material initially formed subaqueous colluvial apron(synonymous with subaqueous fans) where sufficient space was present to accommodate sediments and the basement angle exceeded than the natural angle of repose. As weathering and denudation have progressed, the initial scarps have transformed into confluencetype slopes, and the source material has formed medium-and large-scale debris flows that have entered the lake, resulting in an increase in sediment flux. Consequently, the subaqueous colluvial aprons have rapidly grown and developed subaerial deposits, which have evolved into larger-scale Gilbert-type deltas that overlie the initial apro

关 键 词：Coarse-grained deposits Gilbert-type delta Subaqueous colluvial apron Subaqueous fans SOURCE-TO-SINK Weathering and denudation Sediment input regime Lake Chenghai Quaternary 

分 类 号：P343.5[天文地球—水文科学]