新疆博斯腾湖全新世沉积磁性矿物组成与沉积环境探讨

摘要/Abstract

摘要： 中国西北干旱区湖泊沉积物存在磁性矿物种类复杂和磁化率普遍偏低等问题，使得利用环境磁学手段重建古环境、古气候的方法受到了限制。选择新疆博斯腾湖BST12B钻孔顶部岩芯（深度0～2.5 m）不同沉积相的代表性样品，进行载磁性矿物富集，并将原样品和富集获得的样品分别做XRD（X荧光衍射）岩石矿物检测。结果显示，所有湖相样品中均有黄铁矿和磁铁矿检出，而没有磁黄铁矿和针铁矿检出，说明博斯腾湖全新世湖相沉积物的主要磁性矿物是磁铁矿，并含有少量黄铁矿；富集获得的样品中粘土矿物（如绿泥石等）含量明显增加，石英、长石和方解石含量降低，富集后的残留样品的磁化率大幅度降低，说明粘土矿物对干旱区湖泊沉积物的磁学贡献不容忽视。结合沉积物粒度、色度、硫元素含量以及沉积物磁性矿物的组合特征推断，黄铁矿可以作为湖泊高水位的指示矿物种类，因而具有重建湖泊古水位变化的潜力，并应用到博斯腾湖的全新世湖泊环境重建，发现博斯腾湖BST12B钻孔位置早全新世为接近氧化环境的浅湖相环境，而中晚全新世为深湖相沉积环境并存在一个浅水的湖滨相沉积环境。研究结果说明，利用载磁性矿物富集的方法对干旱区湖泊沉积物中所含磁性矿物进行富集后检测是开展干旱区湖泊环境磁学研究的可行手段，对研究湖泊环境变化具有重要意义。

关键词: 干旱区, 博斯腾湖, 全新世, 环境磁学, 磁性矿物

Abstract: The long standing issues that low values of magnetic susceptibility as well as uncertainty of magnetic mineral types of lake sediments in arid area of northwest China are widely existed,making it limited in using the environmental magnetism methods to estimate the lake evolution as well as to reconstruct their regional paleoenvironment and paleoclimate. Low values of magnetic susceptibility could enlarge the instrument error,while the uncertainty of magnetic mineral types of lake sediments may confuse researchers in studying the mechanism of enhanced magnetic susceptibility. To solve these problems,we extracted magnetic minerals with self-regulating magnetic mineral-extracting device from 5 samples chosen from different sedimentary units from the top 2.5 m of BST12B(42°00'42.9"N,87°09'53.8"E)drilling core which was collected in the depth of 9.2 m in the central area of Bosten Lake in winter of 2012 and had the total length of 51.52 m. We tested mineral compositions of all the 5 samples both before and after extracting using XRD(X-Ray Diffraction)method,which had been proved to be very efficient in identifying minerals quantificationally. Results show that all the lacustrine samples contained Magnetite and Pyrite,neither Pyrrhotite nor Goethite were detected in all the samples,which meant that the major magnetic minerals in Holocene lacustrine sediments of Bosten Lake were magnetite and bits of pyrite. Moreover, in comparison with the residual parts,the extracted parts enriched clay minerals,such as Chlorite and Mica, which were widely distributed in lacustrine sedimentary environment and had relatively high magnetic susceptibility value. While the concentration of the major minerals in our tested samples,Quartz,Feldspar and Calcite decreased dramatically. As a result,the values of magnetic susceptibility of these residual parts decreased synchronously, which indicated that the magnetism contribution of these clay minerals made to the lacustrine sediments in arid area should not be ignored. Combining the characteristics of magnetic minerals assemblage with other climate proxies that include particle size,color and concentration of Sulfur,we can infer that the Pyrite can be potentially used as a high lake water level indicator which has been used in the estimation of the Holocene lake evolution in Bosten Lake. The reconstructed result indicates that the lake water level of Bosten Lake was very low,or even just a seasonal waterlogged environment during the early Holocene,while the deep water environment sustained from middle to late Holocene except an episode of short-term shore-environment appeared which may result from an extremely drought event. As a summary,our work illustrates that the using of magnetic mineral extracting method is viable in exploring the lacustrine sediments environmental magnetism problems in arid areas, and is of significant meanings in studying lake evolution and environment change. The specific type of magnetic mineral,Pyrite could be potentially used in assessing lake level fluctuation.

Key words: arid area, Bosten Lake, Holocene, environmental magnetism, magnetic mineral

中图分类号:

P534.63

谢海超, 魏海涛, 王强, 黄小忠, 彭卫, 陈发虎. 新疆博斯腾湖全新世沉积磁性矿物组成与沉积环境探讨[J]. 干旱区地理, 2017, 40(3): 512-522.

XIE Hai-chao, WEI Hai-tao, WANG Qiang, HUANG Xiao-zhong, PENG Wei, CHEN Fa-hu. Relationship between magnetic minerals and there sedimentary environment of Holocene sediments from Bosten Lake,Xinjiang[J]. , 2017, 40(3): 512-522.

参考文献

[1] THOMPSON R,OLDFIELD F. Environmental magnetism[M]. London:Allen&Unwin,1986:1-227.

[2] ROBINSON S G. The late Pleistocene palaeoclimatic record of North Atlantic deep-sea sediments revealed by mineral magnetic measurements[J]. Physics of Earth and Planetary Interiors, 1986,(42):22-57.

[3] THOMPSON R,BLOEMENDAL J,DEARING J A,et al. Environmental applications of magnetic measurements[J]. Science, 1980,(207):481-486.

[4] LIU S Z,DENG C L,XIAO J L et al. High-resolution enviromagnetic records of the last deglaciation from Dali Lake,Inner Mongolia[J]. Palaeogeography,Palaeoclimatology,Palaeoecology, 2016,(454):1-11.

[5] 申洪源,贾玉连,郭峰. 内蒙古黄旗海湖泊沉积物磁化率特征及其环境意义[J]. 干旱区地理,2010,33(2):151-157.[SHEN Hongyuan,JIA Yulian,GUO Feng. Characteristics and environmental significance of the magnetic susceptibility in sediment of Huangqihai Lake,Inner Mongolia,China[J]. Arid Land Geography, 2010,33(2):151-157.]

[6] CHEN F H,LIU J B,XU Q H et al. Environmental magnetic studies of sediment cores from Gonghai Lake:implications for monsoon evolution in North China during the late glacial and Holocene[J]. Journal of Paleolimnology,2013,(49):447-464.

[7] HELLER F,LIU T S. Magnetism of Chinese loess deposits[J]. Geophysical Journal of the Royal Astronomical Society,1984, (77):125-141.

[8] KUKLA G,HELLER F,MING L X et al. Pleistocene climates in China dated by magnetic susceptibility[J]. Geology,1988, (16):811-814.

[9] LIU T S,DING Z L. Chinese loess and the paleomoonsoon[J]. Annual Review of Earth and Planetary Sciences,1998,(26): 111-145.

[10] 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.

[11] LIU X M,HESSE P,Rolph T et al. Properties of magnetic mineralogy of Alaskan loess:evidence for pedogenesis[J]. Quaternary International,1999,(62):93-102.

[12] HELLER F,LIU T S. Magnetostratigraphical dating of loess deposits in China[J]. Nature,1982,(300):431-433.

[13] CHEN F H,BLOEMENDAL J,WANG J M,et al. High-resolution multi-proxy climate records from Chinese loess,evidence for rapid climatic changes over the last 75 kyr[J]. Palaeogeography Palaeoclimatology Palaeoecology,1997,(130):323-335.

[14] DING Z L,DERBYSHIRE E,YANG S L et al. Stacked 2.6-Ma grain size record from the Chinese loess based on five sections and correlation with the deep-sea delta O-18 record[J]. Paleoceanography, 2002,17(3).

[15] LANCI L,HIRT A M,LOWRIE W,et al. Mineral-magnetic record of late Quaternary climatic changes in a high Alpine lake[J]. Earth Planetary Science Letters,1999,(170):49-59.

[16] HU S Y,DENG C L,APPEL E,et al. Environmental magnetic study on lacustrine sediments[J]. Chinese Science Bulletin, 2002,(47):613-616.

[17] TUDRYN A,TUCHOLKA P,GIBERT E,et al. A late Pleistocene and Holocene mineral magnetic record from sediments of Lake Aibi,Dzungarian Basin,NW China[J]. Journal of Paleolimnology, 2010,44(1):109-121.

[18] DEARING J A. Magnetic susceptibility[M]// WALDEN J, OLDFIELD F,SMITH J,eds. Environmental magnetism:a practical guide No.6. London:Quaternary Research Association, 1999:35-62.

[19] ROBERTS A P,PIKE C R,VEROSUB K L. First-order reversal curve diagrams:a new tool for characterizing the magnetic properties of natural samples[J]. Journal of Geophysical Researchatmospheres, 2000,(105):28461-28475.

[20] GEISS C E,BANERJEE S K. A multi-parameter rock magnetic record of the last glacial-interglacial paleoclimate from southcentral Illinois,USA[J]. Earth Planetary Science Letters,1997, (152):203-216.

[21] 许英勤. 新疆博斯腾湖地区全新世以来的孢粉组合与环境[J]. 干旱区地理,1998,21(2):43-49.[XU Yingqin. The assemblage of Holocene spore pollen and its environment in Bosten Lake area Xinjiang[J]. Arid Land Geography,1998,21(2): 43-49.]

[22] 张英,夏敦胜,赵瑞瑞,等. 新疆博斯腾湖湖滨沉积物的磁学特征及其环境意义[J]. 海洋地质与第四纪地质,2013,(4):93- 102.[ZHANG Ying,XIA Dunsheng,ZHAO Ruirui,et al. Magnetic propertites of the lakeshore sediments of the Bosten Lake, Xinjiang,China and their environmental implications[J]. Marine Geology & Quaternary Geology,2013,(4):93-102.]

[23] 黄小忠,陈发虎,肖舜,等. 新疆博斯腾湖沉积物粒度的古环境意义初探[J]. 湖泊科学,2008,20(3):291-297.[HUANG Xiaozhong, CHEN Fahu,XIAO Shun,et al. Primary study on the environmental significances of grain-size changes of the Lake Bosten sediments[J]. Journal of Lake Sciences,2008,20(3): 291-297.]

[24] 范育新,赵晖,陈发虎,等. 博斯腾湖湖泊沉积物光释光年代测量[J]. 第四纪研究,2007,27(4):568-575.[FAN Yuxin,ZHAO Hui,CHEN Fahu,et al. OSL dating of lacustrine sediments from Lake Bosten[J]. Quaternary Sciences,2007,27(4):568-575.]

[25] 张成君,曹洁,类延斌,等.中国新疆博斯腾湖全新世沉积环境年代学特征[J]. 沉积学报,2004,22(3):494-499.[ZHANG Chengjun,CAO Jie,LEI Yanbin,et al. The chronological characteristics of Bosten Lake Holocene sediment environment in Xinjiang, China[J]. Acta Sedimentologica Sinica,2004,22(3): 494-499.]

[26] 钟巍,舒强. 南疆博斯腾湖近12.0 ka BP以来古气候与古水文状况的变化博斯腾湖全新世湖相沉积相碳酸盐稳定同位素与古气候的初步研究[J]. 海洋与湖沼,2001,32(2):213-220.[ZHONG Wei,SHU Qiang. Palaeoclimatic and Palaeohydrologic oscillations since about 12.0 ka BP at Bosten Lake,southern Xinjiang[J]. Oceanologia Et Limnologia Sinica,2001,32(2): 213-220.]

[27] MISCHKE S and WUNNEMANN B. The Holocene salinity history of Bosten Lake(Xinjiang,China)inferred from ostracod species assemblages and shell chemistry:possible palaeoclimatic implications[J]. Quaternary International,2006,(154):100- 112.

[28] 张成君,郑绵平,ALEXANDER P,等. 博斯腾湖碳酸盐和同位素组成的全新世古环境演变高分辨记录及与冰川活动的响应[J]. 地质学报,2007,81(12):1658-1671.[ZHANG Chengjun, ZHENG Mianping,ALEXANDER Prokopenko,et al. The plaeoenvironmental variation from the high-resolution record of the Holocene sediment carbonate andisotopic composition in Bosten Lake and responding to glacial activity[J]. Acta Geologica Sinica,2007,81(12):1658-1671.]

[29] 张家武,王君兰,郭小燕,等. 博斯腾湖全新世岩芯沉积物碳酸盐氧同位素气候意义[J]. 第四纪研究,2010,30(6):1078- 1087.[ZHANG Jiawu,WANG Junlan,GUO Xiaoyan et al. Paleoclimatic significance of oxygen isotope composition of carbonates from a sediment core at Bosten Lake,Xinjiang,China[J]. Quaternary International,2010,30(6):1078-1087.]

[30] WUNNEMANN B,CHEN F H,RIEDEL F,et al. Holocene lake deposits of Bosten lake,southern Xinjiang,China[J]. Chinese Science Bulletin,2003,48(14):1429-1432.

[31] WUNNEMANN B,MISCHKE S,CHEN F H. A Holocene sedimentary record from Bosten Lake,China[J]. Palaeogeography, Palaeoclimatology,Palaeoecology,2006,234(2):223-238.

[32] 陈发虎,黄小忠,杨美临,等. 亚洲中部干旱区全新世气候变化的西风模式——以新疆博斯腾湖记录为例[J]. 第四纪研究, 2006,26(6):881-887.[CHEN Fahu,HUANG Xiaozhong, YANG Meilin,et al. Westerly dominated Holocene climate model in arid central Asia:case study on Bosten Lake,Xinjiang,China[J]. Quaternary Sciences,2006,26:881-887.]

[33] 陈发虎,黄小忠,张家武,等. 新疆博斯腾湖记录的亚洲内陆干旱区小冰期湿润气候研究[J]. 中国科学:(D 辑),2007,37 (1):77-85.[CHEN Fahu,HUANG Xiaozhong,ZHANG Jiawu, et al.Humid little ice age in arid central Asia documented by Bosten Lake,Xinjiang,China[J]. Science in China Series(D), Earth Sciences,2007,37(1):77-85.]

[34] 郭召杰,张志诚,钱祥麟,等. 新疆焉耆盆地构造特征及其石油地质意义[J]. 石油实验地质,1998,20(3):205-209.[GUO Shaojie,ZHANG Zhicheng,QIAN Xianglin,et al. The structural styles and their role in hydrocarbon accumulation of the Yanqi Basin,NW China[J]. Experimental Petroleum Geology,1998, 20(3):205-209.]

[35] 王苏民,窦鸿身. 中国湖泊志[M]. 北京:科学出版社,1998: 345-346.[WANG Sumin,DOU Hongshen. China Lake Blog[M]. Beijing:Science Press,1998:345-346.]

[36] 程其畴. 博斯腾湖研究[M]. 南京:河海大学出版社,1995:1-7.[CHENG Qichou. Bosten Lake Research[M]. Nanjing:Hohai University Press,1995:1-7.]

[37] 刘丽梅,赵景峰,张建平,等. 近50 a 博斯腾湖逐年水量收支估算与水平衡分析[J]. 干旱区地理,2013,36(1):33-40.[LIU Limei,ZHAO Jingfeng,ZHANG Jianping et al. Water balance of Lake Bosten using annual water-budgets method for the past 50 years[J]. Arid Land Geography,2013,36(1):33-40.]

[38] 李吉均. 中国西北地区晚更新世以来环境变迁模式[J]. 第四纪研究,1990,(3):197-204.[LI Jijun. The patterns of environmental changes since late Pleistocene in Northwestern China[J]. Quaternary Sciences,1990,(3):197-204.]

[39] 石培宏,杨太保,田庆春,等. 靖远黄土-古土壤色度变化特征分析及古气候意义[J]. 兰州大学学报(自然科学版),2012,48 (2):15-23.[SHI Peihong,YANG Taibao,TIAN Qingchun,et al. Chroma characteristics in the loess-paleosol at Jingyuan section and its signification to paleocliamete[J]. Journal of Lanzhou University(Natural Sciences),2012,48(2):15-23.]

[40] 曹洁,张家武,张成君,等. 青藏高原北缘哈拉湖近800 年来湖泊沉积及其环境意义[J]. 第四纪研究,2007,27(1):100-107.[CAO Jie,ZHANG Jiawu,ZHANG Chengjun,et al. Environmental changes during the past 800 years recorded in lake sediments from Hala Lake on the Northern Tibetan Plateau[J]. Quaternary International,2007,27(1):100-107.]

[41] 罗超,杨东,彭子成,等. 新疆罗布泊地区近3.2 万年沉积物的气候环境记录[J]. 第四纪研究,2007,27(1):114-121.[LUO Chao,YANG Dong,PENG Zicheng,et al. Climatic and environmental records in the sediment of the Luobei Billabong in Lop Nur,Xinjiang in recent 32 ka[J]. Quaternary International, 2007,27(1):114-121.]

[42] 刘青松,邓成龙. 磁化率及其环境意义[J]. 地球物理学报, 2009,52(4):1041-1048.[LIU Qingsong,DENG Chenglong. Magnetic susceptibility and its environmental significances[J]. Chinese Journal of Geophysics,2009,52(4):1041-1048.]

[43] WU D,ZHOU A F,LIU J B,et al. Changing intensity of human activity over the last 2,000 years recorded by the magnetic characteristics of sediments from Xingyun Lake,Yunnan,China[J]. Journal of Paleolimnology,2014,(53):47-60.

[44] LIU Q S,BANERJEE S K,JACKSON M J,et al. New insights into partial oxidation model of magnetite and thermal alteration of magnetic mineralogy of the Chinese loess in air[J]. Geophysical Journal International,(158):506-514.

[45] TORRES M A,WEST A J,LI G J. Sulphide oxidation and carbonate dissolution as a source of CO₂ over geological timescales[J]. Nature,2014,507:346-349.

[46] 成艾颖,余俊清,高春亮,等. 湖泊沉积物微量元素ICP-AES与 XRF分析方法和相关性研究[J]. 光谱学与光谱分析,2013,33 (7):1949-1952[. CHENGAiying,YU Junqing,GAO Chunliang, et al. Study on trace elements of lake sediments by ICP-AES and XRF core scanning[J]. Spectroscopy and Spectral Analysis, 2013,33(7):1949-1952.]

[47] HELMKE J P,SCHULZ M,BAUCH H A. Sediment-color record from the Northeast Atlantic reveals patterns of millennial- scale climate variability during the past 500,000 years[J]. Quaternary Research,2002,(57):49-57.

[48] JI J,SHEN J,BALSAM W,et al. Asian monsoon oscillations in the northeastern Qinghai-Tibet Plateau since the late glacial as interpreted from visible reflectance of Qinghai Lake sediments[J]. Earth and Planetary Science Letters,2005,233(1):61-70.

[49] CHEN F,YU Z C,YANG M,et al. Holocene moisture evolution in arid central Asia and its out-of-phase relationship with Asian monsoon history[J]. Quaternary Science Reviews,2008, (27):351-364.

[50] HUANG X Z,CHEN F H,FAN Y X,et al. Dry late-glacial and early Holocene climate in arid central Asia indicated by lithological and palynological evidence from Bosten Lake,China[J]. Quaternary International,2009,(194):19-27.