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湖泊、黄土与古土壤、深海沉积物等连续沉积体的磁化率变化作为环境变化的替代性指标被广泛应用,然而对于非连续、能够反映特定时段气候变化的沉积体,如冰川沉积物的磁化率却较少涉及。本文通过对青藏高原东缘8个典型冰川发育山地冰碛物磁化率进行研究,并与黄土、湖泊、深海沉积物以及不同区域的表土磁化率进行对比,采用质量磁化率和频率磁化率探讨冰碛物的磁化率特点及其影响因素。结果表明:青藏高原东缘山地的冰碛物质量磁化率呈宽幅波动,介于(3.01~1808.80)×10-8m3.kg-1,平均值147.84×10-8m3.kg-1;频率磁化率值较低、且波动幅度小,介于0~6.89%,平均值为1.37%。不同时空条件下冰碛物的磁化率特点不同,即不同地点同一冰期磁化率的差异显著;同一地点不同冰期冰碛物的磁化率变化不明显。影响冰碛物磁化率的主导因素是母岩的岩性条件,气候因素起次要作用。
The change of magnetic susceptibility of continuous sediments, such as lakes, loess and paleosol, and deep-sea sediments, has been widely used as an alternative indicator of environmental change. However, for discontinuous sediments that can reflect climate change in specific periods, such as glacial sediments, Rate is less involved. In this paper, the magnetic susceptibility of glacial moraines in eight typical glacial developed mountains in the eastern margin of the Qinghai-Tibet Plateau is studied and compared with that of loess, lakes, deep-sea sediments and topsoil in different regions. The mass magnetic susceptibility and frequency magnetic susceptibility Characteristics of magnetic susceptibility of moraines and their influence factors. The results show that the magnetic susceptibility of the moraine in the eastern mountains of the Qinghai-Tibet Plateau fluctuates widely, ranging from (3.01-1808.80) × 10-8m3.kg-1 with an average of 147.84 × 10-8m3.kg-1. Frequency magnetization The rate is low, and the fluctuation range is small, ranging from 0 to 6.89% with an average of 1.37%. The characteristics of the magnetic susceptibility of the moraines are different under different temporal and spatial conditions, that is, the magnetic susceptibilities of the same ice age are significantly different in different locations. The changes of the magnetic susceptibility of glacial moraines at different locations are not obvious. The dominant factor affecting the susceptibility of moraines is the lithology of the parent rock, with climatic factors playing a secondary role.