Studia Geologica Polonica  vol. 101 (Abstracts)

Trinity Peninsula Group (Permo-Triassic?) at Paradise Harbour, Antarctic Peninsula

Krzysztof BIRKENMAJER

Abstract
The Trinity Peninsula Group (Permo-Triassic ?) at Paradise Harbour, Danco Coast, Antarctic Peninsula, is represented by the Paradise Harbour Formation (new unit), more than 1000 m thick. It is subdivided into three members: the Almirante Brown Member (ABM), more than 500 m thick (base unknown); the Skontorp Cove member (SCM) about 200 m thick; and the Mount Inverleith Member (MIM), 100-300 m thick. This is a marine clastic succession, corresponding to distal turbidite facies (ABM and SCM), and to distal submarine delta (MIM).
The whole succession is devoid of body megafossils and microfossils. MArine trace fossils have been found only at transition from the ABM to the SCM units.
The Paradise Harbour Formation (PHF) was strongly folded probably close to the Triassic-Jurassic boundary when Se-vergent thrust faults were formed. During the Jurassic-earliest Cretaceous time, the formation was subject to strong erosion and weathering, then unconformably covered by a  huge pile of Cretaceous basic lavas, finally intruded by Cretaceous granitoids and late-magmatic acidic and basic dyke complex. Refolding of the PHF together with its lava cover, and SE-vergent thrusting of the whole complex, took place probably during Late Cretaceous.

Studia Geologica Polonica, 101: 27-82.

Volcanic succession at Deception Island, West Antarctica: A revised lithostratigraphic standard

Krzysztof BIRKENMAJER

Abstract
New lithostratigraphic standard is proposed for the Quaternary volcanic succession at Deception Island, South Shetland Islands (West Antarctica). The succession is subdivided into the older Foster Group (redefined group) which includes pre-caldera volcanics, and the younger Hawkes Group (new group) which includes syn-caldera and post-caldera volcanics and volcanic forms. The Foster Group consists of four formations (new units): the Entrance Fm. (basaltic and basaltic andesite lavas and pyroclastics); the Cathedral Fm. (agglomerates); the Stonethrow Fm. (basaltic adesite lavas alternating with agglomerates); and the Window Fm. (trachybasalt dykes). The Hawkes Group consists of seven formations (new units): the Murature Fm. (andesitic lapilli tuff, destroyed ring tephra cones); the Ronald Fm. (trachydacite lava and plug); the Collins Fm. (trachydacite lava flows, tuffs, craters and destroyed cones); the Chacao Fm. (basaltic andesite tephra cones and maars); the Casco Fm. (basaltic andesite tephra cones with craters); the Kirkwood Fm. (basaltic lavas and tephra; fissure eruptions and craters); and the Telefon Fm. (andesitic tephra cones, lavas and tephra cover associated with fissure eruptions, maars). The Telefon Fm. (three phases) relates to the 1967-1970 volcanic activity; the Kirkwood Fm. includes the 1842 event and the events between 1829 and 1912; all older formations pre-date 1829