Metals in topsoil in Larsemann Hills, an ice-free area in East Antarctica: Lithological and anthropogenic inputs

Although metal accumulation has been investigated in coastal Antarctic soil, the information about to what extent station activities influence soil quality remains limited, especially in East Antarctica. Here, we carried out an investigation on element accumulation (Pb, Zn, Cu, Ni, Mn, Cr, Ti, Zr, Fe, Ca, K, Al, Mg and Na) in topsoils collected from Larsemann Hills, the second largest oasis along East Antarctica. Results show that metal contents in soils generally fall within the ranges of local rocks, suggesting a dominant source of parent minerals. In spatial, a content gradient of Pb was found, with elevated values inside station areas, while no obvious trend was found for other metals. Contents of total organic carbon (TOC) and nitrogen are rather low, and no association exists between metals and TOC or nitrogen, suggesting a minor role of nutrients in soil metal accumulation in this cold-xeric environment. Chemical weathering assessment suggests a low degree of chemical weathering in topsoils in Larsemann Hills. The results of multivariate statistical analysis suggest that lithological inputs are the dominant source of soil metals, and the different metal groups are likely associated with different geochemistry of elements during weathering process. Among the observed 14 metals, only soil Pb levels was affected by local human activities, but this influence is only confined to inside station areas. The influences of marine inputs and long-range pollutant transport on metal levels in topsoils were found to be negligible.