Magnesium-poor adakites have been found at Monte Burney. Fueguino volcanic rocks also include adakites but these are richer in magnesium. These adakitic magmas reflect the subduction of a relatively hot and young Antarctic Plate. In the case of Monte Burney, these magmas then underwent some fractionation during ascent, as it was retarded by the tectonic regimen, which is somewhat compressive.