云南大理点苍山末次冰期冰碛物石英砂扫描电镜形态特征分析
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摘要
云南大理点苍山是大理冰期的命名地,保存有确切的末次冰期冰川作用遗迹.对点苍山冰碛物石英砂进行了扫描电镜形态特征分析,获得了其石英砂形态特征及其频率,并在冰川成因的典型特征的频率上取得了新的认识.扫描电镜分析表明,点苍山冰碛物石英砂形态特征主要为:石英砂形状主要为次棱角状、尖棱角状和多棱角状,边缘多可见次棱脊和棱脊磨损,表面起伏度高;机械特征主要有贝壳状断口、平行解理面、裂隙、粘附碎片、擦痕、机械V形坑;化学特征主要有蚀坑和蚀缝、蜂窝状溶蚀表面、无定形硅沉淀和硅质薄膜.在石英砂表面与冰川作用密切相关的擦痕的频率为8%~32%;粘附碎片的频率为16%~40%;裂隙的频率为12%~32%.通过对点苍山冰碛物的石英砂扫描电镜分析,得出该第四纪海洋性冰斗冰川和悬冰川的石英砂形态特征及其频率.该冰碛物石英砂原始形态特征明显,机械特征频率不高,是近源堆积的冰碛物石英砂的典型形态特征.
Diancang Mountain is the place where the concept of Dali Glaciation was put forward,and it is synonymous with the Last Glaciation in China. In this study,we applied Scanning Electron Microscopy(SEM)to the samples of Quaternary glacial sediments from the Diancang Mountain. According to the SEM analysis,the main surface microtextures of quartz grains from the Quaternary glacial sediments in Diancang Mountain are as follows:the quartz grains are mainly subangular and sharp angular outline,subedge ridge,high relief in shape;mechanical characters are mainly conchoidal fractures,parallel cleavages,crevasses,adhering particles,striations,V- shaped percussion cracks;chemical features are dissolution pits and grooves,honeycombed solution surface,Si O2 precipitates and silicon film. The features most related to glacial genesis are striations,with its frequency of 8%- 32%;adhering particles,with its frequency of 16%- 40%;cracks with its frequency of12%- 32%. According to the SEM of glacial sediments of Diancang Mountain,we obtained the microtextures and its frequency of maritime cirque glacier and hanging glacier. The quartz grains of the glacial sediments are characterized by original features,and glacial mechanical microtextures are not well developed.
Diancang Mountain is the place where the concept of Dali Glaciation was put forward,and it is synonymous with the Last Glaciation in China. In this study,we applied Scanning Electron Microscopy(SEM)to the samples of Quaternary glacial sediments from the Diancang Mountain. According to the SEM analysis,the main surface microtextures of quartz grains from the Quaternary glacial sediments in Diancang Mountain are as follows:the quartz grains are mainly subangular and sharp angular outline,subedge ridge,high relief in shape;mechanical characters are mainly conchoidal fractures,parallel cleavages,crevasses,adhering particles,striations,V- shaped percussion cracks;chemical features are dissolution pits and grooves,honeycombed solution surface,Si O2 precipitates and silicon film. The features most related to glacial genesis are striations,with its frequency of 8%- 32%;adhering particles,with its frequency of 16%- 40%;cracks with its frequency of12%- 32%. According to the SEM of glacial sediments of Diancang Mountain,we obtained the microtextures and its frequency of maritime cirque glacier and hanging glacier. The quartz grains of the glacial sediments are characterized by original features,and glacial mechanical microtextures are not well developed.
引文
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[2]Liu Beibei,Zhang Wei,Cui Zhijiu,et al.Climate-tectonics coupling effect on Late Quaternary Glaciation in the Mayaxue shan,Gansu Province[J].Journal of Glaciology and Geocryology,2015,37(3):701-710.[刘蓓蓓,张威,崔之久,等.青藏高原东北缘玛雅雪山晚第四纪冰川发育的气候和构造耦合[J].冰川冻土,2015,37(3):701-710.]
[3]Yang Jianqiang,Cui Zhijiu,Yi Chaolu,et al.“Tali Glaciation”on Massif Diancang[J].Science in China:Series D,2007,50(11):1685-1692.[杨建强,崔之久,易朝路,等.关于点苍山“大理冰期”[J].中国科学D辑:地球科学,2007,37(9):1205-1211.]
[4]Yang Jianqiang,Zhang Wei,Cui Zhijiu,et al.Late Pleistocene Glaciation of the Diancang and Gongwang Mountains,southeast margin of the Tibetan plateau[J].Quaternary International,2006,154/155:52-62.
[5]Zhao Jingdong,Wang Jie,Yin Xiufeng.Quaternary glaciations research in China:current status and controversy[J].Journal of Glaciology and Geocryology,2013,35(1):119-125.[赵井东,王杰,殷秀峰.中国第四纪冰川研究的现状与争议-兼记首届“中国第四纪冰川与环境变化”研讨会[J].冰川冻土,2013,35(1):119-125.]
[6]Su Zhen,Zhao Jingdong,Zhen Benxing.Distribution and features of the glaciers’ELAs and the decrease of ELAs during the Last Glaciation in China[J].Journal of Glaciology and Geocryology,2014,36(1):9-19.[苏珍,赵井东,郑本兴.中国现代冰川平衡线分布特征与末次冰期平衡线下降值研究[J].冰川冻土,2014,36(1):9-19.]
[7]Rai S.Depositional environments of Quaternary deposits of the Son Valley as revealed by scanning electron microscopy[J].Sedimentary Geology,1987,52:127-148.
[8]Campbell S,Thompson I C.The palaeoenvironmental history of Late Pleistocene deposits at Moel Tryfan,North Wales:evidence from Scanning Electron Microscopy(SEM)[J].Proceedings of the Geologists’Association,1991,102:123-134.
[9]Mahaney W C.Scanning electron microscopy of Pleistocene sands from Yamal and Taz peninsulas,Ob River estuary,northwestern Siberia[J].Quaternary International,1998,45-46:49-58.
[10]Immonen N.Surface microtextures of ice-rafted quartz grains revealing glacial ice in the Cenozoic Arctic[J].Palaeogeography,Palaeoclimatology,Palaeoecology,2013,374:293-302.
[11]Vos K,Vandenberghe N,Elsen J.Surface textural analysis of quartz grains by scanning electron microscopy(SEM):from sample preparation to environmental interpretation[J].EarthScience Reviews,2014,128:93-104.
[12]Helland P E,Huang Peihua,Diffendal R F.SEM Analysis of Quartz Sand Grain Surface Textures Indicates Alluvial/Colluvial Origin of the Quaternary“Glacial”Boulder Clays at Huangshan(Yellow Mountain),East-Central China[J].Quaternary Research,1997,48:177-186.
[13]Wu Xihao,Jiang Fuchu,Xu Heling,et al.Macroscopic and microscopic features of the Quaternary glacial vestiges in the Tanzhesi area of the Western Hills of Beijing[J].Journal of Geomechanics,1997,3(4):3-12.[吴锡浩,蒋复初,徐和聆,等.北京潭柘寺地区第四纪冰川遗迹的宏观和微观特征[J].地质力学学报,1997,3(40):3-12.]
[14]Chen Andong,Tian Mingzhong,Zhao Zhizhong,et al.Genetic type analysis and ESR dating of Quaternary deposit along Mumachang profile in Lushan Mountain in Jiangxi Province[J].Acta Geoscientica Sinica,2014,35:111-118.[陈安东,田明中,赵志中,等.江西庐山牧马场剖面泥砾堆积物的成因分析及年代测定[J].地球学报,2014,35(1):111-118.]
[15]Chen Andong,Tian Mingzhong,Zhao Zhizhong,et al.Macroscopic and microscopic evidence of Quaternary glacial features and ESR dating in the Daweishan Mountain area,Hunan,eastern China[J].Quaternary International,2014,333:62-68.
[16]Mahaney W C,Stewart A,Kalm V.Quantification of SEM microtextures useful in sedimentary environmental discrimination[J].Boreas,2001,29:35-51.
[17]Sun L G,Liu X D,Yin X B,et al.Sediments in palaeonotches:potential proxy records for palaeoclimatic changes in Antarctica[J].Palaeogeography,Palaeoclimatology,Palaeoecology,2005,218:175-193.
[18]Strand K,Immonen N.Dynamics of the Barents-Kara ice sheet as revealed by quartz sand grain microtextures of the late Pleistocene Arctic Ocean sediments[J].Quaternary Science Reviews,2010,29:3583-3589.
[19]Fang Aimin,Liu Xixoahan,Lee J I,et al.Sedimentary environments of the Cenozoic sedimentary debris found in the moraines of the Grove Mountains,east Antarctica and its climatic implications[J].Progress in Natural Science,2004,14:30-41.
[20]Mahaney W C,Claridge G,Campbell I.Microtextures on quartz grains in tills from Antarctica[J].Palaeogeography,Palaeoclimatology,Palaeoecology,1996,121:89-103.
[21]Le Baron J C,Grab S W,Kuman K.2011.Surface texture analysis of southern Tuli Basin sediments:implications for Limpopo Valley geoarchaeological contexts[J].Journal of African Earth Sciences,1996,59:384-394.
[22]Costa P J M,Andrade C,Mahaney W C,et al.Aeolian microtextures in silica spheres induced in a wind tunnel experiment:comparison with aeolian quartz[J].Geomorphology,2013,180-181:120-129.
[23]Shi Lei,Zhang Yue,Chen Yixin,et al.Quartz grain SEM microtextures analyses of sub-glacial deposits at Hailuogou glacier[J].Acta Scientiarum Naturalium Universitatis Pekinensis,2010,46:96-102.[石磊,张跃,陈艺鑫,等.贡嘎山海螺沟冰川沉积的石英砂扫描电镜形态特征分析[J].北京大学学报(自然科学版),2010,46(1):96-102.]
[24]Liu Xiaodong,Sun Liguang,Yin Xuebin,et al.Characteristics of surface textures of quartz in the wave cut notch in the Fildes Penisula of Antarctica and their environmental significance[J].Marine Geology and Quaternary Geology,2002,22(1):37-42.[刘晓东,孙立广,尹雪斌,等.南极无冰区古海蚀龛石英颗粒表面结构特征及其环境意义[J].海洋地质与第四纪地质,2002,22(1):37-42.]
[25]Yin Xuebin,Sun Liguang,Liu Xiaodong.Characteristics of quartz grain surface textures in the Antarctic ice-free area[J].Chinese Journal of Polar Research,2003,15(1):1-10.[尹雪斌,孙立广,刘晓东.南极无冰区典型沉积环境石英砂表面结构特征及其在沉积环境识别中的应用[J].极地研究,2003,15(1):1-10.]
[26]Newsome D,Ladd P.The use of quartz grain microtextures in the study of the origin of sand terrains in Western Australia[J].Catena,1999,35(1):1-17.
[27]Chen Lihua,Miao Xin,Yu Zhong.Scanning electron microscopy and its application on geology[M].Beijing:Science Press,1986:1-44.[陈丽华,缪昕,于众.扫描电镜在地质上的应用[M].北京:科学出版社,1986,1-44.]
[28]Wu Yongqiu,Cui Zhijiu,Ge Daokai,et al.Surface character and sedimentary environment of the quartz grains in the Quaternary strata in Kunlun Mountains Pass area[J].Journal of basic science and engineering,1988,6(2):117-124.[伍永秋,崔之久,葛道凯,等.昆仑山垭口地区第四纪地层石英砂表面特征与沉积环境[J].应用基础与工程科学学报,1998,6(2):117-124.]
[29]Mahaney W C,Kalm V.Comparative scanning electron microscopy study of oriented till blocks,glacial grains and Devonian sands in Estonia and Latvia[J].Boreas,2000,30:165-171.
[30]Mahaney W C,Vortisch W,Julig P.Relative differences between glacially crushed quartz transported by mountain and continental ice-some examples from North America and east Africa[J].American Journal of Science,1988,288:810-826.
[31]Li Minghui,Kang Shichang,Zheng Mianping.Surface textures on quartz grains from the Zhabuye Saline Lake in the middle Tibet Plateau since 142 ka BP[J].Journal of Glaciology and Geocryology,2008,30(1):125-131.[李明慧,康世昌,郑绵平.青藏高原中部扎布耶茶卡142 ka以来石英砂表面特征及其环境意义[J].冰川冻土,2008,30(1):125-131.]
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