Abstract:

Based on three short sediment cores collected in Prydz Bay (Antarctica) during the 29th Chinese National Antarctic Research Expedition, the rare earth element (REE) contents, sediment grain sizes, and biogenic proxies were determined to discuss the pattern and controlling factors of the REE distribution. The results showed that the REEs of Prydz Bay sediments vary in content but have similar shale-normalized distribution patterns, i.e., rich in light REEs, to upper continental crust and metamorphic rocks from Zhongshan Station, indicating they have the same terrigenous provenance. Based on the sediment grain size, major elements, and biosourced proxies, it is suggested that sediment provenance is the major controlling factor behind REE composition. Moreover, biological action might dilute the REE concentration, making the grain-size effect invalid. The REE proxies in the sediment profile were almost stable with depth, reflecting similar terrigenous inputs and depositional environments on the century scale. In addition, the δCe values generally decreased downward, suggesting a gradual decreasing trend in oxidability within the sediment core.

Key words: Prydz Bay, Antarctica, sediment, REEs, geochemistry