Lithostratigraphy, age and distribution of Eocene volcanic sequences on eastern King George Island, South Shetland Islands, Antarctica

Abstract New mapping and dating of volcanic outcrops on the east coast Admiralty Bay, King George Island, has demonstrated that Eocene sequences are dominant also crop out extensively elsewhere, particularly eastern part island. The can be divided into at least three formations (Hennequin, Cape Vauréal Carruthers Cliff) together with strata Warkocz near Lions Rump currently unassigned stratigraphically. recently published 40 Ar/ 39 Ar ages indicate all Early in age, mainly Ypresian, extending to Lutetian possibly even Priabonian time more easterly outcrops. Compositional contrasts exist between groups (calc-alkaline vs tholeiitic). composed lavas, many show evidence for contemporary inundation by water. They interbedded sedimentary rocks deposited during flooding events as debris flows, avalanches, hyperconcentrated from traction currents lakes. common presence juvenile detritus suggests sediments were probably linked explosive hydrovolcanic eruptions, some which rooted summit ice caps. Other is permissive, but Island not well established present.