塔里木盆地现代天然降尘磁性特征时空对比研究

doi:10.7522/j.issn.1000-694X.2013.00120

摘要/Abstract

摘要：

塔里木盆地是北半球中、高纬度粉尘的重要源区。本研究在盆地南部的民丰县设置现代粉尘采样点,于2006年1月至2007年12月逐月采集样品。研究结果表明民丰县自然粉尘的月沉降通量为49.95 g·m-2,春、夏、秋季数值接近,冬季最低。粉尘中磁性矿物含量低,晶体粒径粗,矫顽力高,赤铁矿含量低。塔里木盆地自然粉尘和黄土高原黄土的磁学性质对比分析结果显示：黄土高原黄土的初始磁化率略低于塔里木盆地的现代降尘,二者的原生强磁性矿物的晶体粒径较粗,约为5 μm。粉尘在黄土高原沉积后,随着成壤过程中的生物化学风化作用加强,大量细粒强磁性矿物生成。同时,赤铁矿含量的增加也是指示成壤作用强度的重要标志。在塔里木盆地,人为源粉尘的磁性特征主要表现在强磁性和较低的矫顽力两方面。对盆地边缘地区的城市粉尘调查结果发现：北部城市粉尘的人为源输入强度高,磁学信号强;南部城市相对较弱。这与当地的经济发展状况、人口密度具有良好对应关系。环境磁学是进行粉尘环境监测和物源示踪的有效手段。

关键词: 塔里木盆地, 黄土高原, 降尘, 黄土, 环境磁学

Abstract:

Tarim Basin is one of the most important sources of dust on the earth, especially in north hemisphere. In this study, samples of dustfall were collected at each month from January of 2006 to December of 2007 in Minfeng county of Tarim Basin, and a set of environmental magnetic parameters (χlf, χfd%, χARM, SIRM, HIRM and Hcr) were measured. Results suggest that the mean monthly dust deposition flux values is 49.95 g\5m2, with low in winter and high in spring, summer and autumn. The magnetic assemblage in the dustfall is dominated by coarse grained and high coercivity magnetite being associated with maghaemite and haematite. The contrast between dustfall and Loess Plateau loess reveals that the primary strong magnetic mineral is slightly lower than dustfall in Tarim Basin, and both of which present coarse grain size of magnetic mineral (about 5 μm). Furthermore, the magnetic investigation also suggests hematite concentration enhancement in loessic soil is another important signal of pedogenic. Anthropogenically derived particulate matter presents higher ferrimagnetic mineral concentration and low coercivity in Tarim Basin. The contrast of dustfall in different cities of Tarim Basin indicates that magnetic signal is strong in cities (Aksu, Korla) in north and weak in south, which has a good corresponding relationship with economic development and population density. Environmental magnetism is an effective measurement in monitoring dust pollution and its tracing source.

Key words: Tarim Basin, Loess Plateau, dustfall, loess, environmental magnetism

中图分类号:

X513

王博1, 许淑婧1, 夏敦胜1,2,贾佳1,赵爽1. 塔里木盆地现代天然降尘磁性特征时空对比研究[J]. 中国沙漠, 2013, 33(3): 840-849.

WANG Bo1, XU Shu-jing1, XIA Dun-sheng1,2, JIA Jia1, ZHAO Shuang1. Spatial and Temporal Characteristics in Magnetic Properties of Dustfall in Tarim Basin, Northwestern China[J]. JOURNAL OF DESERT RESEARCH, 2013, 33(3): 840-849.

参考文献

[1]刘东生.黄土与环境[M].北京:科学出版社,1985:1-43.

[2]Fang X M,Lv L Q,Yang S L,et al. Loess in Kunlun Mountains and its implications on desert development and Tibetan Plateau uplift in west China[J].Science in China(Series D),2002,45(4):289-299.

[3]Sun J M.Source regions and formation of the loess sediments on the high mountain regions of Northwestern China[J].Quaternary Research,2002,58:341-351.

[4]Maher B A,Prospero J M,Mackie D,et al.Global connections between Aeolian dust,climate and ocean biogeochemistry at the present day and at the last glacial maximum[J].Earth-Science Reviews,2010,99:61-97.

[5]Maher B A.The magnetic properties of Quaternary aeolian dust and sediments,and their palaeoclimatic significance[J].Aeolian Research,2011,3(2):87-144.

[6]Sun J M.Provenance of loess material and formation of loess deposits on the Chinese Loess Plateau[J].Earth and Planetary Science Letters,2002,203:845-859.

[7]Heller F,Liu T S.Magnetostratigraphical dating of loess deposits in China[J].Nature,1982,300:431-433.

[8]Heller F,Liu T S.Magnetism of Chinese loess deposits[J].Geophysical Journal Royal Astronomical Society,1984,77:125-141.

[9]Guo Z T,Ruddiman W F,Hao Q Z,et al.Onset of Asian desertification by 22 Myr ago inferred from loess deposits in China[J].Nature,2002,416:169-163.

[10]Ding Z L,Xiong S F,Sun J M,et al.Pedostratigraphy and Paleomagnetism of a 7.0 Ma eolian loess-red clay sequence at Lingtai,Loess Plateau,north central China and the implication for paleomonsoon evolution[J].Palaeogeography,Palaeoclimatology,Palaeoecology,1999,152:49-66.

[11]贾佳,夏敦胜,魏海涛,等.阿西克剖面记录的西天山地区黄土磁学性质及古气候意义初探[J].中国沙漠,2011,31(6):1406-1415.

[12]Maher B A.Paleorainfall reconstructions from pedogenic magnetic susceptibility variations in the Chinese loess and paleosols[J].Quaternary Research,1995,44:383-391.

[13]吕厚远,韩家懋,吴乃琴,等.中国现代土壤磁化率分析及其古气候意义[J].中国科学(B辑),1994,24:1290-1297.

[14]Deng C L,Zhu R X,Verosub K L,et al.Mineral magnetic properties of loess/paleosol couplets of the central loess plateau of China over the last 1.2 Myr[J].Journal of Geophysical Research,2004,109,B002532.

[15]Liu Q S,Banerjee S K,Jackson M J,et al.Grain sizes of susceptibility and anhysteretic remanent magnetization carriers in Chinese loess/paleosol sequences[J].Journal of Geophysical Research,2004,109,B002747.

[16]Liu Q S,Jackson M J,Yu Y,et al.Grain size distribution of pedogenic magnetic particles in Chinese loess/paleosol[J].Geophysical Research Letters,2004,31,GL021090.

[17]Liu Q S,Jackson M J,Banerjee S K,et al.Mechanism of magnetic susceptibility enhancements of the Chinese loess[J].Journal of Geophysical Research,2004,109,B003249.

[18]Liu Q S,Deng C L,Torrent J,et al.Review of recent developments in mineral magnetism of the Chinese loess[J].Quaternary Science Reviews,2007,26:368-385.

[19]Maher B A.Rain and dust:magnetic records of climate and pollution[J].Elements,2009,5(4):229-234.

[20]Xia D S,Yang L P,Ma J Y,et al.Magnetic property of Lanzhou dustfall and its implication in urban pollution[J].Science in China(Seriers D),2007,50:1724-1732.

[21]Xia D S,Chen F H,Bloemendal J,et al.Magnetic properties of urban dustfall in Lanzhou,China,and its environmental implications[J].Atmospheric Environment,2008,42:2198-2207.

[22]夏敦胜,王冠,马剑英,等.兰州市大气降尘环境磁学特征研究[J].中国沙漠,2007,27(5):859-865.

[23]乔庆庆,张春霞,李静,等.北京市朝阳区大气降尘磁学特征及对空气污染物浓度的指示[J].地球物理学报,2011,54(1):151-162.

[24]王丽,夏敦胜,余晔,等.北疆地区城市大气降尘磁学特征及其环境意义[J].中国沙漠,2010,30(3):699-705.

[25]王博,夏敦胜,余晔,等.城市降尘磁性特征对比及其环境意义[J].兰州大学学报(自然科学版),2010,46(6):11-17.

[26]孙东怀,苏瑞侠,陈发虎,等.黄土高原现代天然降尘的组成、通量和磁化率[J].地理学报,2001,56(2):171-180.

[27]倪刘建,张甘霖,阮心玲,等.南京市不同功能区大气降尘的沉降通量及污染特征[J].中国环境科学,2007,27(1):2-6.

[28]徐茜,赵景波.新疆沙尘暴活动与气候条件的关系[J].干旱区资源与环境,2007,21(12):116-120.

[29]刘新春,钟玉婷,王敏仲,等.塔里木盆地大气降尘变化特征及影响因素分析[J].中国沙漠,2010,30(4):954-960

[30]刘新春,钟玉婷,何清,等.塔克拉玛干沙漠腹地沙尘暴过程大气颗粒物浓度及影响因素分析[J].中国沙漠,2011,31(6):1548-1553

[31] Thompson R,Oldfield F.Environmental Magnetism[M].London:Allen & Unwin,1986:55-127.

[32]Tarling D H,Hrouda F.The Magnetic Anisotropy of Rocks[M].London:Chapman & Hall,1993:217.

[33]贾佳,夏敦胜,魏海涛,等.耀县黄土记录的全新世东亚冬夏季风非同步演化[J].第四纪研究,2009,29(5):1-10.

[34]贾佳,夏敦胜,魏海涛,等.黄土高原西部典型古土壤与黄土的磁学特征及其古气候意义[J].兰州大学学报(自然科学版),2011,46:26-31.

[35]李冠华,夏敦胜,赵爽,等.新疆塔城地区黄土沉积的磁学特征及其对古环境变化的指示[J].中国沙漠,2012,32(6):1565-1575.

[36]夏敦胜,魏海涛,马剑英,等.中亚地区现代表土磁学特征及其古环境意义[J].第四纪研究,2006,26(6):937-946.

[37]Wei H T,Xia D S,Chen F H,et al.Magnetic characteristics of topsoil from Xinjiang,Northwestern China,and their implications[J].Frontiers Earth Science in China,2009,3(3):259-265.

[38]Liu Q S,Barrón V,Torrent J,et al.Magnetism of intermediate hydromaghemite in the transformation of 2-line ferrihydrite into hematite and its paleoenvironmental implications [J].Journal of Geophysical Research,2008,113,B005207.

[39]张春霞,黄宝春,刘青松.钢铁厂周围不同污染介质的磁学特征及其环境意义[J].地球物理学报,2009,52:2826-2839.