LAUSR

The geomorphic dynamics on ice-free areas are crucial for understanding soil formation, vegetation and landscape stability in maritime Antarctic. We aimed to describe the soil formation on different landforms, following the Holocene glacial retreat at Stinker Point. Twenty profiles were sampled and classified, grouped into three landforms units: middle platforms and scarps, till/glacial deposits and present/Holocene raised beaches. Soil chemical and physical attributes were determined, and the vegetation type identified and quantified. Soils from till and glacial deposits can be separated by the age of exposure: older soils are stony, skeletic; and recently exposed till has soils with moderate depth, alkaline reaction and very high base saturation. Soils at the middle platforms are shallow, coarse-grained, skeletic, with abundant vegetation. Soils from the present-day beaches are alkaline, very coarse with no horizon differentiation, whereas soils on Holocene beaches are acid and nutrient-rich due to past or present-day influence of fauna. Soils from Stinker Point are generally shallow, skeletic and strongly related to the landforms and biogenic influences. Compared with other islands of the South Shetlands, in Elephant Island soil development is less pronounced, being this mainly attributed to the metamorphic nature of parent material, with greater resistance to weathering.