Natural variability of major and trace elements in non-ornithogenic Gelisoils at Edmonson Point, northern Victoria Land, Antarctica

Abstract

Antarctica is perceived as one of the most pristine environments on Earth, though increasing human activities and global climate change raise concerns about preserving the continent’s environmental quality. Limited in distribution, soils are particularly vulnerable to disturbances and pollution, yet lack of baseline studies limits our abilities to recognize and monitor adverse effects of environmental change. To improve the understanding of natural geochemical variability of soils, a survey was conducted in the fellfield environments of Edmonson Point (Victoria Land). Soil samples were analyzed for six major (Fe, Ca, Mg, Na, K and Ti) and 24 trace elements (As, Ba, Be, Bi, Cd, Co, Cr, Cs, Cu, Ga, Li, Mn, Mo, Ni, Pb, Rb, Sn, Sr, Tl, U, V, Y, Zn and Zr). Relationships among element concentrations in the samples and local bedrock were analyzed to identify their origin and similarities in geochemical cycles. Element concentrations in the soils were highly variable but generally within the lowest values reported elsewhere in Antarctica. Though values of Cd, Mn, Ni and Zn were relatively high, they are consistent with those in the local soil-forming rocks indicating an origin from natural sources rather than anthropogenic contamination. Chemical composition of soils vs. rocks pointed to alkali basalts as the lithogenic source of the soil matrix, but also indicated considerable alteration of elemental composition in the soil. Considering local environmental settings, the soil elemental content was likely affected by marine-derived inputs and very active hydrological processes which enhanced leaching and removal of mobilized elements. Both of these processes may be of particular importance within the context of global climate change as the predicted increases in temperature, water availability and length of the summer season would favor mineral weathering and increase geochemical mobility of elements.

Keywords

• antarctic
• victoria land
• soil
• pedogenesis
• weathering
• geochemistry
• natural background