Fernanda M. Canile, A. C. Rocha-Campos, Paulo R. dos Santos, and Luiz E. Anelli. Instituto de Geociências, Universidade de São Paulo, São Paulo, Brazil
Recession of the Wyspianski glacier margin (Wesele Cove, King George Island) of > 60 m, since 1993, exposed a thick (over 60 m), tilted (25º to SE) terrestrial succession of well preserved >13 lava flows of the Mazurek Point Formation (Eocene), and an extensive outcrop (>150,000 m2) of diamictites and sandstones from the Krakowiak Glacier Member. Each flow (2-7m thick) is made up of a lower, fresh, compact basalt zone (1-6 m thick), that grades to an upper weathered, massive, clay-rich interval (1-1.5 m thick), bearing relict basalt clasts. At one point the diamictites rest erosively on top of basalt. Features of the diamictites point to subglacial deposition in glacial-marine and possibly also in terrestrial settings. Thin sections and geochemical analyses indicate that zoning of the predominantly tholeiitic basalt flows may be assigned to weathering processes under mild climatic conditions that preceded the onset of Oligocene glaciation.
