Neutron activation analysis on sediments from Victoria Land, Antarctica: multi-elemental characterization of potential atmospheric dust sources

Abstract

The elemental composition of 40 samples of mineral sediments collected in Victoria Land, Antarctica, in correspondence of ice-free sites, is presented. Concen- tration of 36 elements was determined by instrumental neutron activation analysis, INAA. The selection of 6 standard reference materials and the development of a specific analytical procedure allowed to reduce measure- ments uncertainties and to verify the reproducibility of the results. The decision to analyze sediment samples from Victoria Land ice-free areas is related to recent investiga- tions regarding mineral dust content in the TALos Dome ICE core (15911 0 E; 7249 0 S, East Antarctica, Victoria Land), in which a coarse local fraction of dust was rec- ognized. The characterization of Antarctic potential source areas of atmospheric mineral dust is the first step to identify the active sources of dust for the Talos Dome area and to reconstruct the atmospheric pathways followed by air masses in this region during different climatic periods. Principal components analysis was used to identify ele- ments and samples correlations; attention was paid spe- cially to rare earth elements (REE) and incompatible/ compatible elements (ICE) in respect to iron, which proved to be the most discriminating elemental groups. The ana- lysis of REE and ICE concentration profiles supported evidences of chemical weathering in ice-free areas of Victoria Land, whereas cold and dry climate conditions of the Talos Dome area and in general of East Antarctica.