马兴悦^1,2,,
吕镔^1,2,3,,,
赵国永⁴,
陈梓炫^2,3,
郑兴芬^2,3,
潘妙龄⁵
1. 福建师范大学地理学国家级实验教学示范中心, 福建 福州 350007
2. 福建师范大学地理科学学院, 福建 福州 350007
3. 福建师范大学湿润亚热带山地生态国家重点实验室培育基地, 福建 福州 350007
4. 信阳师范学院地理科学学院, 河南 信阳 464000
5. 福建师范大学物理与能源学院, 福建 福州 350007

基金项目: 国家自然科学基金项目(批准号:41402149、41772180和41602187)、福建师范大学大学生创新创业训练计划项目(批准号:cxxl-2017197)和福建师范大学创新团队项目(批准号:IRTL1705)共同资助


详细信息

作者简介: 马兴悦, 女, 22岁, 地理科学(国家人才培养基地)专业本科生, E-mail:lzmxy122@163.com

通讯作者: 吕镔, E-mail:lvbin@fjnu.edu.cn

中图分类号: P318

收稿日期:2019-03-28
修回日期:2019-06-02
刊出日期:2019-09-30

Magnetic properties and their influence factors of Lixian loess in western Sichuan Plateau

Ma Xingyue^1,2,,
Lü Bin^1,2,3,,,
Zhao Guoyong⁴,
Chen Zixuan^2,3,
Zheng Xingfen^2,3,
Pan Miaoling⁵
1. National Demonstration Center for Experimental Geography Education, Fujian Normal University, Fuzhou 350007, Fujian
2. School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, Fujian
3. State Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province, Fujian Normal University, Fuzhou 350007, Fujian
4. School of Geographic Sciences, Xinyang Normal University, Xinyang 464000, Henan
5. College of Physics and Energy, Fujian Normal University, Fuzhou 350007, Fujian


More Information

Corresponding author: Lü Bin,E-mail:lvbin@fjnu.edu.cn

MSC: P318

--> Received Date: 28 March 2019
Revised Date: 02 June 2019
Publish Date: 30 September 2019


摘要
摘要:川西高原河谷阶地和断陷盆地广泛分布厚层风成黄土-古土壤序列，目前对其磁学性质变化机制及古气候意义研究还很薄弱。文章对该区理县黄土-古土壤剖面进行了系统的岩石磁学研究，确定了其磁性矿物种类、含量和颗粒大小的特征及其变化规律。通过结合粒度、色度与地球化学参数，进一步探讨了理县黄土-古土壤磁性的主控因素。结果表明：1）理县剖面同时含有强磁性矿物（为磁铁矿和磁赤铁矿）以及弱磁性矿物（为赤铁矿和针铁矿）；2）相对黄土层，古土壤层含有更高比例的亚铁磁性矿物；3）成土过程中生成的大量细小强磁性矿物颗粒，是古土壤层S₁磁化率增加的主导因素，该模式与黄土高原相似；4）结合色度以及磁学性质，可以较为明确地区分成壤强度；（5）理县黄土剖面物源复杂，磁学特征受到沉积物来源、后期流水和气候的共同作用，利用单一磁学性质（比如磁化率）进行古气候研究会造成多解性。
关键词: 理县黄土/
岩石磁学/
成壤作用/
古气候/
川西高原

Abstract:The thick-layer eolian loess-paleosol sequences are widely distributed in the valley terraces and faulted basins of Western Sichuan Plateau. The study on the magnetic properties and paleoclimatic significance of it is still very weak. This paper systematically measured the rock-magnetic parameters of the loess-paleosol section (31.45°N, 103.66°E; 2066 m a.s.l.) in Lixian. The profile is 6.7 m thick and 135 samples were collected at 5 cm intervals. The types, contents and grain size of magnetic minerals and the changing regulations are confirmed. Combined on the grain sizes, chroma and geochemistry parameters, the factors affecting the magnetic properties of the Lixian loess-paleosol section are further discussed. Our results present:(1) The Lixian section contains both strongly magnetic minerals (magnetite and maghemite) and weakly magnetic minerals (hematite and goethite). (2) Relative to the loess layers, the paleosol layers have a higher proportion of ferrimagnetic minerals. (3) The formation of a large quantity of fine strongly magnetic mineral particles in the process of pedogenic soil formation is the dominant factor of the enhance of paleosol layer S₁, which is similar to that of Chinese Loess Plateau. (4) Combining with the chroma parameters and magnetic properties, the intensity of soil can be clearly distinguished. (5) Lixian loess-paleosol section is of complex provenance, and the magnetic properties are influenced by the sources of the sediment, as well as the fluviation and climate conditions after deposition. So the study on paleoclimate by using a single magnetic property (such as magnetic susceptibility) will result in multi-solution properties.
Key words:Lixian loess/
rock magnetism/
pedogenesis/
paleoclimate/
Western Sichuan Plateau



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