关键词: 江淮地区, 白浆化土壤, 孢粉, 石英砂, 微形态

Abstract:

Basing on the methods of sporo pollen analysis, analysis of arenaceous quartz surface and soil micromorphology, this paper deals with the genetical properties of the albic soils in the Jiang Huai Area in the Northern Subtropical Zone of China. The spore pollen analysis shows the differences between the upper and the lower horizons in soil forming environment. The upper horizon underwent warm temperate forest steppe landscape and subtropical steppe landscape, which belonged to high chemical energetic environment. After the deposition of parent materials, the soil experienced brown soil process or deposition of other materials,then the deposition suspened for long period of time.With the accumulation of new deposits and climate change, the soil forming environment became the subtropical steppe landscape.The basic condition emerged for the formation of yellow brown soil in higher land,and the lower part became marshland with inadequate water drainage. The form of the arenaceous quartz includes its surface shape and structure, and reflects the obvious differences in soil forming environment between the upper and lower horizons. The surface of arenaceous quartz in the lower horizon, especially the illuvial horizon, generally has secondary SiO 2 sediment. As the surface decomposed, some holes formed along the weak region in the quartz sand, and this behavior stands for the high chemical energetic environment. Since the materials constantly deposited and water concentrated, no high chemical energetic environment appeared in the upper horizon. The diffuse and stress stick membranes are found in the thin section of the soil micromorphology.These membranes are the sigh of the secondary clayization.The fabric and light directioal clay membranes formed in the alluvial horizon for the accumulation of clay. Overall,when the Xiashu loess and other loess materials deposited, the climate was the warm temperate forest steppe zone, it then became the northern subtropical forest steppe zone.Finally,the new materials accumated over the loess derived soils.On the bases of the superipositing parent materials,the lower horizon is now at the secondary clayization stage and after the new materials superimposed,the alluvial horizons will have illuviation of clays.

Key words: Jiang Huai Area, Albic soil, spore pollen, arenaceous quartz, micromorphology