位置:成果数据库 > 期刊 > 期刊详情页
青藏高原东南部贡嘎山海螺沟冰川冰下沉积物形成与变形
  • ISSN号:1000-0240
  • 期刊名称:《冰川冻土》
  • 时间:0
  • 分类:P512.42[天文地球—地质学]
  • 作者机构:[1]北京大学城市与环境学院,北京100871
  • 相关基金:Supported by the National Natural Science Foundation of China (Grant Nos. 41230743; 41101003)
中文摘要:

冰岩界面的冰川动力学是冰川系统的重要组成部分,海螺沟冰川地处温暖湿润的海洋环境,冰川运动速度较快,冰川底部接近压融点,是研究冰下过程的较理想地点.在海螺沟冰川大型磨光面上浅显侵蚀坑内发现了碎屑物质.对碎屑物质理化特征研究表明:粒度特征、地球化学与石英砂SEM分析表明沉积在冰岩界面上的物质来自于冰川底部的底碛层,而不是冰上环境的产物.偏光显微镜下观察到的冰下沉积物呈现出一系列塑性变形(微旋转、褶皱)和脆性变形(线性结构、支撑结构、断层)微观结构和构造.两种变形结构的存在是碎屑物质在形成过程中其含水量波动情况的反映.冰下碎屑物质是冰下融出、滞碛作用的共同产物.在整个冰下碎屑物质形成与变形过程中,由于冰下水系季节性变化带来的冰岩界面上冰川水含量的波动起了决定性作用.

英文摘要:

The glacier dynamics at the ice-bed interface form an important element of the glacier system. Hailuogou Glacier is located in a warm and humid environment with maritime characteristics. The bottom of the glacier rich in debris slides intensively and the temperature at the bottom approaches the pressure melting point. Therefore, research on subglacial environment of this glacier makes a significant sense. We have sampled a sequence of subglacial deposits in the shallow eroded depression on the polished sur- faces of Hailuogou Glacier. The investigated site provides evidence of sediment deposition and deforma- tion to understand subglacial processes. We used an integrated approach to demonstrate a subglacial dep- osition and deformation model based on field observation and laboratory analysis. The results of grain- size, geochemical and SEM analyses testify each other that the source materials of the subglacial deposits are derived mainly from the glacier basal layer. Micromorphological work reveals that the subglacial de- posits exhibits a range of ductile deformation microstructures (rotation structures, folding structure) and brittle deformation ones (lineation, edge-to-edge crushing and grain stacking, faulting structure). A sub- glacial deposition model has been established and the model exhibits a complex process including subgla- cial meltwater deposition, lodging. Sediment deposition and deformation is controlled by fluctuations in basal-water pressure, which determine changes in subglaciall meltwater drainage. Therefore subglacial meltwater at the ice-bed interface plays an important role in glacier dynamics, glacier deformation and sediment deposition processes. The maritime feature of Hailouogou Glacier examines this well.

同期刊论文项目
同项目期刊论文
期刊信息
  • 《冰川冻土》
  • 北大核心期刊(2011版)
  • 主管单位:中国科学院 寒区旱区环境与工程研究所
  • 主办单位:中国地理学会 中国科学院寒区旱区环境与工程研究所
  • 主编:程国栋
  • 地址:兰州市天水中路8号
  • 邮编:730000
  • 邮箱:edjgg@lzb.ac.cn
  • 电话:0931-8260767
  • 国际标准刊号:ISSN:1000-0240
  • 国内统一刊号:ISSN:62-1072/P
  • 邮发代号:54-29
  • 获奖情况:
  • 中国自然科学核心期刊,第二届全国优秀地理期刊,甘肃省优秀地理期刊,中国期刊方阵“双效”期刊
  • 国内外数据库收录:
  • 美国地质文献预评数据库,美国剑桥科学文摘,日本日本科学技术振兴机构数据库,中国中国科技核心期刊,中国北大核心期刊(2004版),中国北大核心期刊(2008版),中国北大核心期刊(2011版),中国北大核心期刊(2014版),中国北大核心期刊(2000版)
  • 被引量:17974