Magnetic properties of Lop Nur saline sediments and the environmental implications
Received date: 2020-03-23
Revised date: 2020-05-15
Online published: 2021-03-05
This article presents the particle size, total organic matter, rock magnetic, and x-ray diffraction analyses of saline lake sediments, aeolian sands, Tramarix cone, and yardangs sediments distributed along the west bank of Lop Nur. The aim was to investigate the vertical variations and influencing factors of magnetic characteristics, as well as the paleoenvironmental implications. Based on the magnetic properties, Lop Nur sediments can be divided into two types. In oxidizing environments, sediment magnetic properties are dominated by magnetite, which is consistent with the source materials (Tarim Basin) and are unaffected by early diagenesis. In reducing environments, sediment magnetic properties are dominated by authigenic iron sulfide (greigite and pyrite), which formed in the early diagenesis process. Layers that are dominated by greigite or pyrite have markedly higher or lower χ, SIRM, χARM, and χARM/χ and S-300 mT, respectively, reflect the significant impact of early diagenesis on magnetic properties in the Lop Nur. Combined with the results of chronology from a previous study, we determined that the iron sulfide-bearing sediments were deposited during cold and wet periods, which were probably caused by the North Atlantic cold events that occurred throughout the past 3400 yr. During these periods, iron sulfide formation was likely driven by an enhanced organic matter supply. The magnetic parameters of Lop Nur sediments can be regarded as an indicator of the hydrological and climatic evolution of the Tarim Basin.
Key words: magnetic properties; early diagenesis; saline lake; climate change; Lop Nur
LI Wen,MU Guijin,LIN Yongchong,ZHANG Huijuan,WU Wangyang . Magnetic properties of Lop Nur saline sediments and the environmental implications[J]. Arid Zone Research, 2021 , 38(1) : 257 -266 . DOI: 10.13866/j.azr.2021.01.27
[1] | Zheng M P, Zhang Y S, Liu X F, et al. Progress and prospects of salt lake research in China[J]. Acta Geologica Sinica, 2016,90(4), 1195-1235. |
[2] | 夏训诚, 王富葆, 赵元杰. 中国罗布泊[M]. 北京: 科学出版社, 2007. |
[2] | [ Xia Xuncheng, Wang Fubao, Zhao Yuanjie. China Lop Nur[M]. Beijing: Science Press, 2007. ] |
[3] | 李典鹏, 孙涛, 姚美思, 等. 盐湖区生态系统碳密度及其分配格局[J]. 干旱区研究, 2018,35(4):984-991. |
[3] | [ Li Dianpeng, Sun Tao, Yao Meisi, et al. Carbon density and its distribution pattern of ecosystem in saline region[J]. Arid Zone Research, 2018,35(4):984-991. ] |
[4] | 赵明, 季峻峰, 陈小明, 等. 古盐度对塔北隆起泥岩中粘土矿物组合和绿泥石成分的影响[J]. 高校地质学报, 2015,21(3):365-375. |
[4] | [ Zhao Ming, Ji Junfeng, Chen Xiaoming, et al. Effects of paleosalinity on clay mineral assemblages and chlorite composition in mudstone of Tabei uplift, Xinjiang, China[J]. Geological Journal of China Universities, 2015,21(3):365-375. ] |
[5] | 程国帅, 刘东伟, 温璐, 等. 干涸盐湖地下水和土壤化学属性对自然植被分布的控制作用[J]. 干旱区研究, 2019,36(1):85-94. |
[5] | [ Cheng Guoshuai, Liu Dongwei, Wen Lu, et al. Effects of groundwater and soil chemical properties on distribution of natural vegetation around playa[J]. Arid Zone Research, 2019,36(1):85-94. ] |
[6] | Thompson R, Oldfield F. Environmental Magnetism[M]. London: Alleen and Unwin, 1986. |
[7] | 全婷婷, 陈学刚, 魏疆. 新疆天山天池景区土壤磁学特征及其环境意义[J]. 干旱区研究, 2017,34(6):1286-1293. |
[7] | [ Quan Tingting, Chen Xuegang, Wei Jiang. Magnetic properties of topsoil and iIts environmental implications in the Tianshan Heaven Lake scenic spot, Xinjiang[J]. Arid Zone Research, 2017,34(6):1286-1293. ] |
[8] | Li W, Mu G, Zhang W, et al. Formation of greigite (Fe3S4) in the sediments of saline lake Lop Nur, northwest China, and its implications for paleo-environmental change during the last 8400 years[J]. Journal of Asian Earth Sciences, 2019,174:99-108. |
[9] | 董李, 李艳红. 罗布泊风积物与冲洪积物磁性变化特征的对比研究[J]. 干旱区资源与环境, 2013,27(11):111-116. |
[9] | [ Dong Li, Li Yanhong. Comparative study on magnetic variations of eolian and alluvial-proluvial sediments from Lop Nur area[J]. Journal of Arid Land Resources and Environment, 2013,27(11):111-116. ] |
[10] | 常秋芳, 常宏. 罗布泊Ls2孔近7. 1 Ma以来沉积物的环境磁学研究[J]. 第四纪研究, 2013,33(5):876-888. |
[10] | [ Chang Qiufang, Chang Hong. The environmental magnetism study of core Ls2 in Lop Nur, Tarim since 7. 1 Ma[J]. Quaternary Sciences, 2013,33(5):876-888. ] |
[11] | 高洁, 李从娟, 徐新文, 等. 罗布泊地区引种植物生理生化指标的主成分及其聚类分析[J]. 干旱区研究, 2018,35(1):199-206. |
[11] | [ Gao Jie, Li Congjuan, Xu Xinwen, et al. Principal components and cluster analysis on the physiological and biochemical indexes of introduced plants in Lop Nur[J]. Arid Zone Research, 2018,35(1):199-206. ] |
[12] | Dong Z, Lyu P, Qian G, et al. Research progress in China’s Lop Nur[J]. Earth-Science Reviews, 2012,111(1):142-153. |
[13] | King J, Banerjee S K, Marvin J, et al. A comparison of different magnetic methods for determining the relative grain size of magnetite in natural materials: Some results from lake sediments[J]. Earth and Planetary Science Letters, 1982,59(2):404-419. |
[14] | Ma C, Wang F, Cao Q, et al. Climate and environment reconstruction during the Medieval Warm Period in Lop Nur of Xinjiang, China[J]. Chinese Science Bulletin, 2008,53:3016-3027. |
[15] | Roberts A P. Magnetic properties of sedimentary greigite (Fe3S4)[J]. Earth and Planetary Science Letters, 1995,134(3):227-236. |
[16] | Roberts A P. Magnetic mineral diagenesis[J]. Earth-Science Reviews, 2015,151:1-47. |
[17] | Li C, Yang S, Zhang W. Magnetic properties of sediments from major rivers, aeolian dust, loess soil and desert in China[J]. Journal of Asian Earth Sciences, 2012,45:190-200. |
[18] | Zan J, Fang X, Appel E, et al. New insights into the magnetic variations of aeolian sands in the Tarim Basin and its paleoclimatic implications[J]. Physics of the Earth and Planetary Interiors, 2014,229:82-87. |
[19] | 李文. 罗布泊盐湖沉积物磁性特征及其古环境记录研究[D]. 北京: 中国科学院大学, 2017. |
[19] | [ Li Wen. Magnetic Properties of Sediments of Saline Lake Lop Nur and Its Implications for Paleo-environmental Change[D]. Beijing: University of Chinese Academy of Sciences, 2017. ] |
[20] | 林永崇. 罗布泊湖泊沉积物记录的全新世以来区域环境变化[D]. 北京: 中国科学院大学, 2017. |
[20] | [ Lin Yongchong. Holocene Environmental Change Recorded by Lacustrine Sediments in Lop Nur, Xinjiang[D]. Beijing: University of Chinese Academy of Sciences, 2017. ] |
[21] | Wang Y, Zhang W, Liu X, et al. Formation of greigite under different climate conditions in the Yellow River delta[J]. Science China Earth Sciences, 2014,58(2):300-308. |
[22] | Blanchet C L, Thouveny N, Vidal L. Formation and preservation of greigite (Fe3S4) in sediments from the Santa Barbara Basin: Implications for paleoenvironmental changes during the past 35 ka[J]. Paleoceanography, 2009, 24(2): PA224 |
[23] | 王绍武. 全新世北大西洋冷事件: 年代学和气候影响[J]. 第四纪研究, 2009,29(6):1146-1153. |
[23] | [ Wang Shaowu. Holocene cold events in the north Atlantic: Chronology and climatic impact[J]. Quaternary Sciences, 2009,29(6):1146-1153. ] |
[24] | Xu B, Gu Z, Qin X, et al. Radiocarbon dating the ancient city of Loulan[J]. Radiocarbon, 2017: 1-12. |
[25] | 李康康, 秦小光, 张磊, 等. 罗布泊(楼兰)地区1260~1450 A. D. 期间的绿洲环境和人类活动[J]. 第四纪研究, 2018,38(3) : 720-731. |
[25] | [ Li Kangkang, Qin Xiaoguang, Zhang Lei, et al. The ancient oasis and human activity in Lop Nur (Loulan) region during1260-1450 A. D.[J]. Quaternary Sciences, 2018,38(3) : 720-731. ] |
[26] | Ran M, Zhang C, Feng Z. Climatic and hydrological variations during the past 8000 years in northern Xinjiang of China and the associated mechanisms[J]. Quaternary International, 2015,358:21-34. |
[27] | Lauterbach S, Witt R, Plessen B, et al. Climatic imprint of the mid-latitude Westerlies in the Central Tian Shan of Kyrgyzstan and teleconnections to North Atlantic climate variability during the last 6000 years[J]. Holocene, 2014,24(8):970-984. |
[28] | Liu X Q, Herzschuh U, Shen J, et al. Holocene environmental and climatic changes inferred from Wulungu Lake in northern Xinjiang, China[J]. Quaternary Research, 2008,70:412-425. |
[29] | Jiang Q F, Ji J F, Shen J, et al. Holocene vegetational and climatic variation in westerly-dominated areasof Central Asia inferred from the Sayram Lake in northern Xinjiang, China[J]. Science China: Earth Sciences, 2013,56:339-353. |
[30] | Hong B, Gasse F, Uchida M, et al. Increasing summer rainfall in arid eastern-Central Asia over the past 8500 years[J]. Scientific Reports, 2014,4:5279. |
[31] | Chen F, Jia J, Chen J, et al. A persistent Holocene wetting trend in arid central Asia, with wettest conditions in the late Holocene, revealed by multi-proxy analyses of loess-paleosol sequences in Xinjiang, China[J]. Quaternary Science Reviews, 2016,146:134-146. |
[32] | Zhang J F, Liu, C L, Wu X H, et al. Optically stimulated luminescence and radiocarbon dating of sediments from Lop Nur (Lop Nor), China[J]. Quaternary Geochronology, 2012,10:150-155. |
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