关键词: 风成黄土, 古土壤, 全新世, 汉中盆地

Abstract: Located in the Qinling-Bashan Mountains, the Hanzhong Basin is in an environment of euergreen broadleaf forest of North Asia. It is commonly considered that there is no Quaternary aeolian loess accumulation in the basin because of the barrier of the Taibai Mountain on its northern side. Based on the field investigation and laboratory analysis in this paper, the Holocene sedimentary stratigraphy in the basin is studied. By comparing the results with those of the typical Holocene loess on the Loess plateau, it is revealed that there is the Holocene eolian loess accumlation in Hanzhong Basin, and the Taibai Mountain actually was not the barrier for dust transport by northwest monsoon during the Holocene epoch, in other words, dust could be transported by northwest monsoon over the Qinling Mountains during the Holocene Epoch. Comparing with the Holocene loess in Luochuan, the soil forming process in Hanzhong Basin was more violent, so the content of coarse sand in the loess and the palaeosoil is low, and the content of clay is high. However, the property of the loess in Hanzhong Basin is close to that in Guanzhong Basin.

Key words: Hanzhong Basin, Holocene, aeolian loess