Abstract:

Fifty topsoil samples collected from the eastern part of China from Heilongjiang to Hainan Province have been analyzed for rare earth elements (REEs). The results indicate that the average contents of rare earth elements in topsoils from the eastern part of China are much higher than those in China as well as in the world; it is characterized by LREEenrichment and HREEdepletion with negative δEu and positive δCe; noticeable positive δCe values have been found in the soils from south subtropics and tropics with hothumid climate and intense weathering process; the plot of Ce/Eu against Eu/Sm is proved to be useful to distinguish different parent rocks of topsoil. This study suggests that the distribution characteristic can be used as a tracer for parent rock of soils, but not an index for climatic zone; δCe value can be used as an index of hothumid climate. However, it is currently not well known how the factors such as sedimentary origin, source area and local climate affect the distribution of rare earth elements. More data would be necessary to answer this question.

Key words:  rare earth elements, topsoil, environmental trace, the eastern part of China