HOLOCENE PALEOSOL IN THE REGION OF XI'AN

Holocene paleosol has been called as loessial soil since its existence was determined. Recently, some researchers determined Holocene paleosol around Xi'an as luvic phaeozem or brown earth. However, these opinions about the paleosol are not uniform. In this paper, the characteristics, the types and the forming environment of the Holocene paleosol are discussed by applying the materials of magnetic susceptibility, grain size, contents of CaCO 3, Fe 2O 3 and Al 2O 3, soil micromorphology. These materials reveal that the Holocene paleosol around Xi'an is luvic cinnamon soil developing in warm and humid climate, but not developing in subarid climate. During the forming period of Holocene paleosol, the meean annual rainfall in Xi'an would be 750 mm or more, and the mean annual temperature would be about 15℃. There are deense root infilling with more than 2 m deep, under the bottom of Holocene paleosol, which suggests the existence of the forest at that time.