The environmental conditions in Maritime Antarctica are more favorable to soil development than in continental areas, which is reflected in the content and type of clay minerals present. In this context, soil clay minerals of Fildes Peninsula, South Shetland Islands were studied with the aim of relating them to periglacial and paraglacial processes as possible indicators of initial pedogenic processes. In this work, textural, mineralogical and crystallochemical characterization of clay minerals as well as chemical and physical soil analyses were carried out. The soil samples represented various surface cover types present on Fildes Peninsula. All samples were composed mainly of clay minerals, plagioclase, quartz and minor zeolites and pyroxene. The clay mineral content was very variable and reached up to 63% w/w. The clay minerals present are mainly smectite, vermiculite, chlorite and minor kaolinite, mica, corrensite and interstratified illite–smectite, with smectite and vermiculite dominating in almost all of the samples. The primary minerals display chemical alteration, and smectite formed by alteration of plagioclase. The clay mineral types were related to the parent material, which was affected by low-grade metamorphism and hydrothermal alteration that transformed biotite and chlorite into vermiculite via interstratified chlorite–vermiculite. Furthermore, this process and/or ongoing surface weathering transformed vermiculite into smectite. The genetic relationship observed between vermiculite and smectite suggests progressive alteration and transformation into a phase with intermediate composition between vermiculite and smectite. Therefore, vermiculite could be at least in part the smectite precursor. Samples closer to the current Collins Glacier front are composed mainly of vermiculite, with the greatest chemical variation occurring where the soils were developed from a mixture of initially glacially transported volcanic rocks through periglacial and fluvial processes. The clay minerals from the centre and south of Fildes Peninsula are mixtures of montmorillonite and vermiculite, as well as of chlorite and corrensite in various proportions. The clay minerals in soils developed on the west coast are a mixture of Fe-rich montmorillonite and vermiculite.

The king penguin (Aptenodytes patagonicus) is a pelagic species that breeds on sub-Antarctic islands relatively close to the Antarctic polar front. After a significant decline at the beginning of the twentieth century because of widespread exploitation by sealers, the species’ numbers are currently increasing, with observed local fluctuations. There has also been an increase in the number of sightings in the Antarctic, and recorded breeding attempts in this area. Here we present the history of observations of king penguins from 1977 to 2017 in two Antarctic Specially Protected Areas: ASPA No. 128 Western Shore of Admiralty Bay, and No. 151 Lions Rump, King George Island, South Shetland Islands (Western Antarctic). Additionally, we report on a new breeding site at Lions Rump, the third known breeding site for this species in the South Shetland Islands. Together with observations from other parts of the archipelago, the information in this study supports earlier suggestions of a southerly expansion of this species and of attempts to colonise the Antarctic Peninsula region.