ABSTRACT

The elemental geochemical composition of sediments influenced by seal excrements in the Antarctic Fildes Peninsula has been examined in order to establish the source of organic matter, identify potential bio-elements and explore their potential palaeoecological implications. The combination of total organic carbon concentration (TOC), total nitrogen concentration (TN), organic carbon isotope (δ¹³C) and atomic C/N ratio shows that the organic matter in the sediments with many seal hairs has a marine origin, predominantly derived from seal excrements. Among the determined element/oxide concentrations, S, Se, F, Zn, Hg, FeO and P₂O₅ were found to be remarkably enriched in the sediments influenced by seal excrements with respect to the sediments with few or without seal hairs, and their concentrations displayed strong and positive correlations with organic matter abundance, indicating that they had the same source and transportation mechanism as the in situ organic material. A comparison of these element/oxide concentrations with the seal hair numbers showed that they had similar distribution patterns with depth, and the correlations were positive and statistically significant. Based upon these results, S, Se, F, Zn, Hg, FeO and P₂O₅ in the seal excrement sediments were identified as potential bio-elements and their concentrations could potentially be used as inorganic geochemical indicators for tracking seal palaeoecological processes in the Antarctic region.