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中国沙漠 ›› 2025, Vol. 45 ›› Issue (2): 236-251.DOI: 10.7522/j.issn.1000-694X.2025.00008

• • 上一篇    

库姆塔格沙漠南北两侧中砂至粗粉砂矿物特征及其物源指示

金秉福1(), 于健1,2, 吴波3,4(), 张云吉1, 哈斯额尔敦5, 苏志珠6, 孔德庸7, 韩旭娇5   

  1. 1.鲁东大学 资源与环境工程学院,山东 烟台 264025
    2.南京大学 地理与海洋科学学院,江苏 南京 210023
    3.中国林业科学研究院生态保护与修复研究所 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
    4.三北工程研究院,北京 100091
    5.北京师范大学 地理科学学部 自然资源学院,北京 100875
    6.山西大学 历史文化学院,山西 太原 030006
    7.韶关学院,广东 韶关 512005
  • 收稿日期:2024-12-07 修回日期:2025-01-10 出版日期:2025-03-20 发布日期:2025-03-26
  • 通讯作者: 吴波
  • 作者简介:金秉福(1963—),男,辽宁大连人,博士,教授,研究方向为沉积地质学与碎屑矿物学。E-mail: bingfu_jin@163.com
  • 基金资助:
    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)

Mineral characteristics and provenance indicators of medium to coarse silt from the northern and southern regions of the Kumtagh Desert

Bingfu Jin1(), Jian Yu1,2, Bo Wu3,4(), Yunji Zhang1, Eerdun Hasi5, Zhizhu Su6, Deyong Kong7, Xujiao Han5   

  1. 1.School of Resources and Environmental Engineering,Ludong University,Yantai 264025,Shandong,China
    2.School of Geography and Ocean Science,Nanjing University,Nanjing 210023,China
    3.National Forestry and Grassland Administration Key Laboratory of Desert Ecosystem and Global Change,Institute of Ecological Conservation and Restoration,Chinese Academy of Forestry,Beijing 100091,China
    4.Institute of Great Green Wall,Beijing 100091,China
    5.School of Natural Resources Faculty of Geographical Science,Beijing Normal University,Beijing 100875,China
    6.School and History and Culture,Shanxi University,Taiyuan 030006,China
    7.Shaoguan University,Shaoguan 512005,Guangdong,China
  • Received:2024-12-07 Revised:2025-01-10 Online:2025-03-20 Published:2025-03-26
  • Contact: Bo Wu

摘要:

对采自库姆塔格沙漠核心区南北两侧的51个点位、73个风沙样品(表层、次表层和浅剖面)进行了粒度分析、密度测试以及1~5 Φ宽粒径多粒级碎屑矿物重液分离和显微鉴定。结果显示:库姆塔格沙漠中的流动沙丘主要成分是中细砂,沉积物的平均密度为2.63 g·cm-3,暗色颗粒约30%是重组分,以岩屑为主,含有少量重矿物。沉积物中的重组分含量、矿物种类数,石英、碳酸盐类、闪石族、帘石族、稳定重矿物类和铁质金属矿物类等的矿物含量以及Q/FQ/(F+L)、ZTRUM/SM矿物指数随着粒径变小而增大;而轻、重组分中的岩屑、斜长石和钾长石等含量以及重矿物指数GZi随粒径变小而减小。1~5 Φ碎屑中轻矿物有10种,以石英和斜长石为主;重矿物有35种,以绿帘石、角闪石和褐铁矿为主,石榴子石为特征矿物;轻、重组分中岩屑均占据很高至较高的含量。研究区沉积物成熟度很低,沙漠北部略高于南部。矿物特征和矿物指标皆表明沙漠沙北部比南部经历更为强烈的风化磨蚀和沉积分选,风沙碎屑可能主要来源于沙漠南部毗邻的阿尔金山,是古今冲洪积物和古湖相沉积物由风力驱动活化而成的近地转沙再沉积。

关键词: 重矿物, 轻矿物, 矿物成熟度, 物源, 库姆塔格沙漠

Abstract:

Identification of detrital heavy minerals was carried out using a multiple-window grain size strategy range of 1-5 Φ wide on 73 aeolian sand samples (surface, subsurface, and shallow sections) from 51 sites in the core area of the Kumtagh Desert located in the north and south regions. The samples were consequently subjected to particle size analysis and density testing for certain specimens. The findings indicate that the dominant constituent of the shifting dune in the Kumtagh Desert is medium-fine sand, exhibiting an average sediment density of 2.63 g·cm-3, approximately 30% of the dark particles comprise heavy components, primarily composed of rock debris and containing a minor proportion of heavy minerals. The number of mineral species, the contents of heavy components, quartz, carbonates, amphibole group, epinete group, stable heavy minerals and ferric metal minerals, as well as the mineral indices of Q/FQ/(F+L), ZTR and UM/SM in sediments exhibit an increase with decreasing particle size. Conversely, the content of rock debris, plagioclase, potassium feldspar, and the heavy mineral index GZi in light and heavy fractions exhibited respectively a decrease corresponding to the reduction in particle size. The 1-5 Φ detrites contain a total of 10 light minerals, predominantly quartz and plagioclase. Among the heavy minerals, there are 35 different types, with epidote, hornblende, and limonite being the most abundant, while garnet stands out as the characteristic mineral. The concentration of both light and heavy rock debris is significantly high. The sediment maturity in the study area is significantly low, with a slightly higher level observed in the northern part of the desert compared to the southern part. Both mineral characteristics and mineral indexes indicate that the sand in the northern region has undergone more intense weathering and sedimentary sorting than its counterpart in the south. The aeolian sand debris primarily originates from the Altyn Tagh, which is adjacent to the southern part of the desert. This sand can be considered as "turn into desert sand near the source" redeposited through wind-driven activation of ancient and modern alluvial and palaeo-lacustrine sediments.

Key words: heavy minerals, light minerals, mineral maturity, provenance, Kumtagh Desert

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