The Correlation between the Content of the Different Grain Size and Magnetic Susceptibility in Lacustrine Sediments, Nihewan Basin
YANG Xiao qiang 1,2 LI Hua mei 2 1 (Department of Earth Sciences, Sun Yat Sen University, Guangzhou 510275) 2 (Guangzhou Institute of Geochemistry, CAS, Guangzhou 510640)
The different grain size content range from 0.2～500 μm and magnetic susceptiblity were measured to study the correlation between grain size and magnetic susceptibilty, selected more 800 samples, in Lacustrine sediments from Nihewan Bain. The correlation coefficient of susceptibility with the content of 0.2～35 μm, especially 0.2～7.5 μm, is positive, and with the content of 35～500 μm is negative. This correlation is contrast to the loess deposits on top of profile, which shows the mechanism of magnetic response towards paleoclimate changes in lacustrine sediments is unlike that in loess. So, we can conclude that the susceptibility change in lake (the sediments are mainly allogenic) sediments is controlled by the allogenic magnetic minerals. The fluctuations of susceptibilty indicate the changes of the lake level and paleoclimate.