| This paper measured the loess-red clay sequences magnetic susceptibility (Xl), frequency magnetic susceptibility(Xfd), carbonate, organic matter and free iron oxide content in the Xifeng section, and primary reconstruct palae-climate change by carbonate and free iron oxide content. The result showed: 1) Xl and Xfd possess the same station and the same periodic change current. Xl variety curve show higher breadth and lower frequence fluctuation while Xfd change range low in the loess-palaeosol sequences; Xl show lower breadth and higher frequence fluctuation while Xfd whole ascend in the red clay layers; 2) Carbonate content has obvious reverse relation with magnetic susceptibility change in the loess-palaeosol sequences, while carbonate content marked increase in the red clay; 3) Organic matter content is higher in S0 and S1 layer, while change current is unobvious under S5 layers, special in the red clay; 4) Free iron oxide content is related to the change magnetic susceptibility in the loess-palaeosol sequences while that isn't marked in the red clay. The highest value in the S5 layer, yet the average value in the red clay notable higer than that in the loess-palaeosol sequences; 5) The whole palaeclimate in the Quaternary divided into the three phases: 0～1.1Ma.B.P, 1.1～1.9Ma.B.P and 1.9～2.6Ma.B.P. Especial since 0.1Ma, precipitation and mean annual temperature decrease current showed that there will be drier and colder climate in the future.
|
PDF Full Text Request