中国地质调查2019，Vol.6Issue(2)：68-75,8.DOI:10.19388/j.zgdzdc.2019.02.08
湖南常德南斗姆湖地区早更新世砾石层砾组分析与沉积特征研究
Study on gravel analysis and sedimentary characteristics of the Early Pleistocene gravel layers in Doumuhu district of southern Changde
摘要
Abstract
In order to determine the sedimentary characteristics and depositional environment of the Early Pleistocene gravel layers at the western edge of Dongting Basin, the authors systematically measured and counted several Quaternary gravel profiles in Doumuhu area of South Changde, based on the 1:50 000 geological survey. The results show that the gravels mainly come from the Cambrian or Precambrian strata. The gravel sorting coefficient Sa ranges from 1.16 to 1.64, with some measuring points of Sa>1.40, which indicates that the gravel layers are deposited with strong hydrodynamic force condition and some of gravel layers are rapid accumulation deposits. Most gravel is flat, with the gravel flatness F from 2.06 to 2.32, which is more than 2.0. The weathering degree of the gravel is low to moderate, with strong weathering degree in some gravel, which means that the weathering exposure exists during the gravel movement. The preferred orientation of gravels shows that the paleocurrents mainly come in the direction of SWW-NW, which indicates that the paleoceanography of the gravel deposition is much different from the modern topography. Through comprehensive comparison of the sections, the authors could conclude that the gravel layers are mainly braided fluvial sediments from alluvial-diluvial fans. The results can provide some new ideas about the sedimentary facies and paleoceanography of the layer gravel, and also support the exploration of the primary diamond deposits in this area.关键词
第四系/砾组分析/冲洪积扇/洞庭盆地Key words
Quaternary/gravel analysis/alluvial-proluvial fan/Dongting Basin分类
天文与地球科学引用本文复制引用
刘庚寅,赵伟,魏方辉,罗来,赵睿成,梁恩云..湖南常德南斗姆湖地区早更新世砾石层砾组分析与沉积特征研究[J].中国地质调查,2019,6(2):68-75,8.基金项目
中国地质调查局"湖南1: 5 万常德市、牛鼻滩、斗姆湖、汉寿幅区域地质调查(编号: DD20160029-16)"项目资助 （编号: DD20160029-16）
