Polish Polar Research

The paper deals with Recent and relic phosphatic soils of ornithogenic origin which occur in ice free oasis of the maritime Antarctic Zone (Antarctic Peninsula and King George Island regions). These soils form on rocky and clay weathering covers within and around of penguin rookeries. Their morphology strongly depends on penological character of a substrate and climatic differentiation of a region. They are built of a surface layer of guano and underlying zone of a phosphatized rock. Except organic matter and unstable urates, the guano contains calcium phosphates (fluorapatite somtimes brushite) and magnesium-amonium phosphate (struvite). The phosphatized zone consists of phosphatic- silicate clays in which occur diversified aluminium-iron phosphates bearing potassium and ammonium ions (leucophosphite, minyulite, taranakite, amorphous aluminium phosphate). The guano layer is strongly reduced by erosion and weathering in ornithogenic relic soils left by penguins in areas abandoned by them during Holocene. Formation of a humus horizon of a plant origin may be observed under a vegetation cover in the relic soils. Clays of the phosphatized zone in these areas are transformed in the processes of chemical and mechanical weathering, by mass movements and frost processes.

The glacial and glacio-marine sediments of the Oligocene Polonez Cove and Early Miocene Cape Melville Formations on King George Island (South Shetland Islands, West Antarctica) yield numerous erratic boulders of limestone, in particular archaeocyathan-algal boundstone, oolite, onkolite, and biomicrite. Some of these boulders are fossiliferous and contain archaeocyathans, sponges, inarticulate brachiopods, monoplacophorans, gastropods, hyolithids, trilobites, ostracodes and such enigmatic fossils as: Chancelloria, Coleolella. Dailyatia. Halkieria. Hadimopanella. Hyolithellus. "Lenastella", Mongolitubulus and Torellella. The small shelly fauna appears to be Early Cambrian (Botomian) in age. The boulders of fossiliferous limestones resemble the rocks of the Shackleton Limestone unit in the central Transantarctic Mts. The lithological composition of the boulder assemblage brought to King George Island during the Tertiary glaciations suggests that the Cambrian outcrops around the Weddell Sea are the source of the erratics. The Antarctic Lower Cambrian fauna resembles its analogues in Australia and Asia.

The paper presents an overview of lithostratigraphy and radiochronological and biochronological data for the Tertiary volcanic and sedimentary successions of King George Island, South Shetland Islands (West Antarctica). Special stress was laid on dating fossiliferous terrestrial and marine strata and glacial and glacio-marine deposits of Tertiary age. for which King George Island offers the most complete and so-far best documented standard in the Antarctic Peninsula sector of West Antarctica.

The algal microfossil Bolboforma reticulata Daniels and Spiegler is recorded from the Oligocene-Miocene glacio-marine sediments of King George Island, South Shetland Islands, Antarctica. The record extends the geographic extent of the species to Antarctica.

Rocks of the Legoupil Formation in the Cape Legoupil area were folded about a N70E oriented axis. Later these rocks were affected only by brittle deformation which occurred in four stages: (1) jointing — set I, (2) dyking, (3) faulting and, (4) jointing — set II. Both, folding and subsequent brittle deformation, are hardly compatible with the Mesozoic-Cenozoic eastward subduction of the ancient Pacific ocean crust.