文献类型：期刊文献

中文题名：库姆塔格沙漠北部沉积物色度特征与沙丘表面明暗色斑成因分析

英文题名：Chromatic characteristics of sediments in the northern Kumtagh Desert and analysis of alternating light and dark landscapes on dune surfaces

作者：金秉福[1] 张云吉[1] 哈斯额尔敦[2] 苏志珠[3] 孔德庸[4] 于健[1] 成龙[5,6] 费兵强[5,6] 韩旭娇[2] 张亚茹[3] 李秀彬[7] 赵学勇[8] 吴波[5,6]

第一作者：金秉福

机构：[1]鲁东大学资源与环境工程学院,烟台264025;[2]北京师范大学地理科学学部自然资源学院,北京100875;[3]山西大学历史文化学院,太原030006;[4]韶关学院,韶关512005;[5]中国林业科学研究院生态保护与修复研究所,北京100091;[6]荒漠生态系统与全球变化国家林业和草原局重点实验室,北京100091;[7]中国科学院地理科学与资源研究所,北京100101;[8]中国科学院西北生态环境资源研究院,兰州730000

年份：2024

卷号：79

期号：9

起止页码：2297-2311

中文期刊名：地理学报

外文期刊名：Acta Geographica Sinica

收录：CSTPCD;;EI(收录号：20244317244338);Scopus;北大核心:【北大核心2023】；CSSCI:【CSSCI2023_2024】；CSCD:【CSCD2023_2024】；PubMed;

基金：国家自然科学基金项目(41471151);国家科技基础性工作专项项目(2012FY111700)。

语种：中文

中文关键词：色度;粒度;平行层理;明暗色斑;库姆塔格沙漠

外文关键词：chrominance;grain size;parallel bedding;light and dark patches;Kumtagh Desert

分类号：P931.3

摘要：库姆塔格沙漠北部沙丘表面多呈现褐黑色至灰褐色,在一些羽毛状沙丘(沙垄)表面常出现明暗交错的色斑景观,成为该沙漠独特标识。本文对采自该区表层沉积物样品进行了粒度分析、色粒的目视分类与色度标定以及沉积物色度的仪器测试。研究表明:目视色度指数CI与器测亮度L^(*)和黄度b^(*)有很强的线性对应关系,可以相互替代表达沉积物的颜色和明暗程度。CI和L^(*)与颗粒自身颜色和粒度密切相关,黑色、灰色和褐色来源于碎屑原生岩性和风化物附着物与粗粒径相关性高,表现为色度高、亮度小;而黄色和白色主要为浅色岩石矿物与细粒径相关性高,即色度低、亮度大。沙漠中沉积层理显著,上粗下细的平行层理成为影响沙丘表面色度的重要因素。沙丘表面色度明暗变化是沙粒运动过程中表层粗粒岩屑的蠕动堆积和细粒矿物的风蚀搬运与风动力相适配的结果,色度高的极粗砂(-1.0~0Φ)或极粗砂+粗砂(-1.0~0.5Φ)在表层0~1cm深度内含量只需5%~10%的相对变化就会使沙丘表面相邻区域产生色度不同的明暗色斑,这种现象与沙漠物质组成、风力分选和沉积物所处地貌部位关系紧密,是多种自然因素综合影响的结果。本文可为揭示库姆塔格沙漠及类似沙漠沙丘表面颜色成因及形成机制提供实验模型和数据参考。
The northern part of the Kumtagh Desert exhibits a dark surface color,ranging from brown black to grayish brown.Additionally,certain feather-like dunes often display contrasting patches of light and dark hues on their surfaces,which has emerged as one of the distinctive characteristics defining this desert.The origin of light and dark spots in sand grains was investigated by conducting field surveys from 45 geomorphic sampling sites in the northern Kumtagh Desertin late September to early October 2020 and 2021,75 groups of grain size analysis,39 groups of color grains(434 grain size samples)were identified visually,as well as 157 samples of sediment chroma were determined by colorimeter.The findings demonstrate a robust linear relationship between the visual colorimetric index(CI)and the measured luminance L^(*)as well as yellowness b^(*),indicating their interchangeability in expressing both color and brightness levels of sediment.CI and L^(*)exhibit close associations with particle color and size.The presence of black,gray,and brown hues can be attributed to the primary lithology of clasts and weathered attachments show a strong correlation with coarse rock debris,resulting in high chromaticity but low brightness.On the other hand,yellow and white tones primarily originate from light-colored rocks and minerals that are closely linked to fine particle sizes,leading to low chroma yet high brightness.The desert has obvious sedimentary stratification,in which parallel bedding is characterized by the largest particle size at the top and gradually decreasing downward,and has a major influence on the chromaticity of the dune surface.The variation in surface chroma of sand dunes is the outcome of peristaltic accumulation of coarsegrained rock debris and wind erosion transport of fine-grained minerals during the movement of sand particles.A slight relative change,ranging from 5%to 10%,in very coarse sand with high chroma-1.0~0Φor a mixture of very coarse sand and coarse sand-1.0~0.5Φcan result in different shades of color spots appearing on adjacent areas of the dune surface.The present study can offer experimental models and data references to elucidate the origin and formation mechanism of surface color in sand dunes within the Kumtagh Desert and similar desert environments.