Rare earth elements of aeolian deposits in Northern China and their implications for determining the provenance of dust storms in Beijing

　　【财新网】

　　发布机构：Geomorphology

　　发布日期：2007年7月1日

Abstract

　　This paper contributes to a better understanding of the source of dust storms in northern China and the relationship between these sources and other aeolian sediments in this region. Sediment samples in potential source areas were collected from the Hunshandake Sandy Land， Heaven Desert， the loess deposits of the Bashang area， the mountainous basins and valleys north of Beijing and from the Badain Jaran Desert and Hulunbaier Sandy Land （Fig. 1）. Dust samples were collected in Beijing during two dust storms in March 2002 and April 2006. The laboratory methods used in this study included measurements of abundance of trace elements， in particular the rare earth elements （REEs）， mineral assemblages and grain size. The REE contents， Eu and Ce anomalies show clear differences between various deposits. Provenance is considered to be the key factor influencing REE patterns in the study areas. The REE abundances and patterns indicate that the aeolian sand north of Beijing， such as in the Heaven Desert， is mainly of local origin rather than from desert encroachment from the north. The mineral grains carried in dust storms， however， are highly mixed， and may come partly from local sources but mainly from distant desert regions in western China.