Solos e evolução da paisagem em ambiente periglacial na Península Barton, Antártica marítima

Abstract

Antarctic soils are characterized by low development degree due to low liquid water content. Compared to mainland, Maritime Antactica has a mild climate. These milder conditions allow a much greater development of soils and more significant chemical weathering. The study area is Barton Peninsula, the second largest ice-free area of King George Island (Maritime Antarctica). The Barton Peninsula has soils derived from different lithologies, with basalt / andesite (with pyrite) standing out. This study aimed to evaluate the role of relief in the genesis of sulfated soils. Three pedons were selected, described, sampled, and classified according to Soil Taxonomy and WRB/FAO. Morphological, physical, mineralogical and chemical analysis were performed. The Barton soils present polygenic evolution. The rock shattering caused by freezing and thawing is present as a pedogenetic process. However, the evolution degree of the soils is substantially associated with the acidification by sulphide oxidation. This process promotes the release of elements, such as Fe, which are mobilized by the relief. Consequently, duricrusts (i.e. petroplintic horizons) are formed, characterizing a transformation of the pedological cover. The genesis of these soils shows that the peri-glacial landscape is dynamic and of deep interest in soil-geomorphological investigations.