摘要
【目的】柴达木盆地北部与西南部存在诸多平面形态类似河流的脊状地貌,为探究其成因,进行砾石组构研究,以还原脊状地貌的古沉积环境。【方法】对脊状地貌区21组砾石样品进行数据统计和形貌分析,并与汉江中游砾石层沉积物进行类比。【结果】脊状地貌区圆状与次圆状砾石占比之和介于71.6%~74.0%,扁平形砾石占比介于44.9%~54.0%,脊状地貌区与汉江中游砾石形貌的相关系数介于0.685~0.703。【结论】脊状地貌区砾石为河流沉积,如果以现代柴达木盆地水系参数为依据,脊状地貌所代表的河流古流速、古流量和古年径流量分别为0.217 m/s、1.39 m^(3)/s、0.144 0×10^(8) m^(3);基于河道宽度还原的脊状地貌区的古流量范围为14~16 m^(3)/s,据此推算其古径流深约为2 m,对应的古流速、古流量和古年径流量分别约为0.357 m/s、14.28 m^(3)/s、1.480 1×10^(8) m^(3)。
[Objective]There are many curvilinear ridges that have similar planforms as rivers in the northern and southwestern Qaidam Basin.To investigate their formation mechanism,we conducted research on the fabric of gravel layers to restore the paleo-sedimentary environment of curvilinear ridges.[Methods]Statistical and morphological analyses were performed on 21 sets of gravel samples from the curvilinear ridges and compared with the gravel layer sediments in the middle reaches of the Han River.[Results]The ratio of round and sub-round gravels in the curvilinear ridges area ranges from 71.6%-74.0%,and the ratio of discoid gravels ranges from 44.9%-54.0%.The correlation coefficients of the gravel morphological features between the distribution area of curvilinear ridges in the Qaidam Basin and those in the sampling area of the middle reaches of the Han River range from 0.685-0.703.[Conclusions]The gravels in the curvilinear ridges are fluvial deposits.If based on the modern hydrologic parameters of the Qaidam Basin,the paleocurrent velocity,paleo-discharge,and paleo-annual runoff rate of the river indicated by the curvilinear ridges are 0.217 m/s,1.39 m^(3)/s,and 0.1440×10^(8) m^(3),respectively.The paleo-discharge range of the curvilinear ridges of the Qaidam Basin reconstructed based on the channel width is 14-16 m^(3)/s.Accordingly,the paleo-runoff depth is estimated to be approximately 2 m,and the corresponding paleocurrent velocity,paleo-discharge,and paleo-annual runoff rates are approximately 0.357 m/s,14.28 m^(3)/s,and 1.4801×10^(8) m^(3),respectively.
作者
刘传兵
丁召静
周定通
梅璟
刘天
张婕
赵健楠
王节涛
LIU ChuanBing;DING ZhaoJing;ZHOU DingTong;MEI Jing;LIU Tian;ZHANG Jie;ZHAO JianNan;WANG JieTao(College of Urban and Environmental Sciences,Hubei Normal University,Huangshi,Hubei 435000,China;Key Laboratory of Geological Survey and Evaluation of Ministry of Education,China University of Geosciences(Wuhan),Wuhan,430074 China;Badong National Observation and Research Station of Geohazards,China University of Geosciences(Wuhan),Wuhan 430074,China;Department of Hydrogeology,Wuhan Center of China Geological Survey,Wuhan 430205,China)
出处
《沉积学报》
北大核心
2025年第6期2039-2052,共14页
Acta Sedimentologica Sinica
基金
湖北省重点实验室开放基金(2021F04)
湖北省教育厅科学技术研究项目(Q20222505)
湖北巴东地质灾害国家野外科学观测研究站开放基金(BNORSG202303)
国家自然科学基金项目(42441839)。
关键词
柴达木盆地
脊状地貌
砾石形态
汉江
古水文
Qaidam Basin
curvilinear ridge
gravel morphology
Han River
paleohydrology
