关键词: 乔治王岛;表生地球化学;原始土壤;母岩

Abstract:

The products of hypergenic process show their notable features in comparison with that of endogenic process. This paper discusses the weathering soil-forming process under the conditions of King George Island region by means of correlation between chemical compositions of both primitive soil and parent rocks. From the analysis of sources of chemical elements in the soil and biogenic effect and artificial impact on them in the polar region, the authors infer some features of migration of chemical elements in the primitive environment, and discuss the correlation between abundance of the chemical elements in both soil-forming parent rocks and primitive soil in the Antarctic region. The residual weathering crust in this region is very thin, being at the stage of fragment weathering. A weathering process occurred simultaneously with a soil-forming process, and hence the primitive soil layer is really coincident with the weathering crust. The initial sources of chemical elements in the soil in the polar region are their soil-forming parent rocks. Both S and P enrich in soil in biological process. A few elements (particularly Pb) can be accumulated in the primitive soil layer in the vicinity of the expedition station, reflecting the "internal impact" of artificial activity on the primitive environment. In the polar region, V and Ti are the most stable elements, Ca is the strongest active element, and the migration capacity of Al, Mg, and Mo is close to that of Ca. In the weathering crust on the igneous rocks, the migration capacity of univalent Na and K is weaker than that of divalent (trivalent) Ca, Mg, and (Al), but in the weathering crust on sedimentary rocks their migration capacity is close to each other. Under the conditions of the polar region the wind effect is one of the important factors for material migration. Under the severe cold climate, the weathering process is weak, and short-run ablation of the ice sheet makes the weathering duration very short. The pulifting of land is not favorable to locally preserving the products of weathering and to forming thick sedimentary weathering crust, Because of the immature development of the primitive soil and unstable chemical composition in this area, the correlation between the corresponding chemical elements in soil-forming parent rocks and primitive soil is not close. However, elements As in the igneous rocks and Cu in the sedimentary rocks are then correlated respectively with some sulphophile elements in the primitive soils developed on them. The project is supported by the National Natural Science Foundation of China.