Late Holocene loess deposits and dust accumulation in the alpine meadow belt of the Wutai Shan, China

Abstract

Greyish-yellow to light-brownish silty deposits in the alpine meadow belt of the Wutai Shan (Central China) were originally transported by wind, but are modified to some degree by local reworking and syn-depositional weathering. However, they are generally defined as loess deposits. Radiocarbon dates of wood fragments and charcoal prove that the loessic surficial sediment cover accumulated in the late Holocene. A lowering of the timberline, caused by a climatic deterioration since the Holocene Optimum, as well as the formation and maintainance of the dense alpine meadow vegetation, has probably favoured the accumulation of dust. Additional factors might have been the alternation between possible dust source areas in the deserts of northwestern China and the downwind accumulation area in the topographic mountain barrier of the Wutai Shan.