The Jarlsbergian unconformity at the Late Proterozoic-Early Cambrian boundary, is expressed in the Hecla Hoek Succession of South Spitsbergen as a regional low-angle unconformity, the result of folding and subsequent erosion of the Late Precambrian Jarlsbergian Basin deposits. The unconformity pre-dates the Bonnia-Olenellus trilobite zone; the sedimentary hiatus covers the lowest Cambrian Fallotaspis and Nevadella trilobite zones, and a closer undefined uppermost part of the Late Proterozoic. There are no Varangian (latest Proterozoic) tillites present in south Spitsbergen at the top of the Late Proterozoic metasediment column which is represented by the Gashamna Formation phyllites and associated rocks.

There are two important unconformities in the Calypsostranda Group (late Palaeogene) at Bellsund, Spitsbergen. The first one is the basal angular unconformity of the Skilvika Formation against folded and planated Proterozoic metasediments: the author provides evidence for its primary sedimentary character. The second one is an intraformational erosional disconformity/discontinuity expressed by rapid replacement of coal-bearing terrestrial strata (Skilvika Formation) by shallow-marine strata (Renarddodden Formation).

The area of NW Wedel Jarlsberg Land south of Bellsund (Spitsbergen), between Dunderbukta in the west and the Berzeliustinden mountain group in the east, consists of five fault-bounded blocks: (1) the Renardbreen Block (Middle–Late Proterozoic basement rocks), (2) the Chamberlindalen Block (Late Proterozoic basement rocks), (3) the Martinfjella Block (Late Proterozoic through Early Ordovician basement rocks), (4) the Berzeliustinden Block (Late Proterozoic and Early Ordovician basement rocks covered by Late Palaeozoic–Tertiary platform deposits), (5) the Reinodden Block (Late Palaeozoic and Mesozoic rocks). The paper presents an outline of lithostratigraphy (Middle/Upper Proterozoic–Lower Ordovician: Hecla Hoek Succession) and architecture of the Caledonian basement in which several thrust-sheets and thrust-folds have been recognized. It also discusses some aspects of Tertiary overthrusting, faulting and rotation with affected the basement rocks and remodelled its Caledonian architecture.

Geological investigations of the 4th Polish Geodynamic Expedition to West Antarctica, summer 1990/91, covered the following topics: volcanological studies and mapping at Deception Island; stratigraphic, palaeonotological and sedimentological studies, and mapping of Tertiary glacial and glacio-marine strata on King George Island; sedimentological and mesostructural studies, and mapping at Hurd Peninsula, Livingston Island; and palaeontological sampling of Jurassic (Mount Flora Formation) and Trinity Peninsula Group deposits at Hope Bay, Trinity Peninsula.

The Trinity Peninsula Group (Permo-Triassic?) at Hope Bay, northern Antarctic Peninsula, is represented by the Hope Bay Formation, more than 1200 m thick. It is subdivided into three members: the Hut Cove Member (HBF,), more than 500 m thick (base unknown), is a generally unfossiliferous marine turbidite unit formed under anaerobic to dysaerobic conditions, with trace fossils only in its upper part; the Seal Point Member (HBF2), 170—200 m thick, is a marine turbidite unit formed under dysaerobic conditions, with trace fossils and allochthonous plant detritus; the Scar Hills Member (HBF3), more than 550 m thick (top unknown), is a predominantly sandstone unit rich in plant detritus, probably formed under deltaic conditions. The supply of clastic material was from northeastern sources. The Hope Bay Formation was folded prior to Middle Jurassic terrestrial plant-bearing beds (Mount Flora Formation), from which it is separated by angular unconformity. Acidic porphyritic dykes and sills cut through the Hope Bay Formation. They were probably feeders for terrestrial volcanics of the Kenney Glacier Formation (Lower Cretaceous) which unconformably covers the Mount Flora Formation. Andean-type diorite and gabbro plutons and dykes (Cretaceous) intrude the Hope Bay Formation, causing thermal alteration of its deposits in a zone up to several hundred metres thick. All the above units are displaced by two system of faults, an older longitudinal, and a younger transversal, of late Cretaceous or Tertiary age.

The Polish geological research on King George Island, South Shetland Islands (West Antarctica), during the two past decades (1977-1996) included: stratigraphy, radiometric dating, petrology and geochemistry, sedimentology and palaeoenvironmental studies, volcanology, tectonics, structural geology, Quaternary geology, paleobotany and palaeozoology. The major scientific achievements were: (1) the establishment of formal lithostratigraphic standards for radiometrically-dated Upper Cretaceous through Tertiary magmatic rock sequences and intercalated sediments; (2) the discovery of four Tertiary glaciations and three interglacials, spanning some 30 Ma from Early/Middle Eocene through Early Miocene; (3) the discovery and systematic elaboration of rich terrestrial and marine biota of Late Cretaceous through Early Miocene ages; (4) the reconstruction of changing Late Cretaceous and Tertiary terrestrial and marine palaeoenvironments in a mobile volcanic-arc setting; (5) the determination of age and structural evolution of the island's two Quaternary volcanoes; (6) the reconstruction of the Late Cretaceous through Recent evolution stages of the South Shetland magmatic arc and its backarc Bransfield Basin and Rift, based on tectonic and structural studies.

The rocks exposed along the western coast of Arctowski Peninsula and on offshore islands, Danco Coast (West Antarctica), represent the following lithostratigraphic units: the Trinity Peninsula Group metasediments (?Permian-Triassic); the Antarctic Peninsula Volcanic Group lavas, agglomerates and tuffs (Lower Cretaceous); the Andean Intrusive Suite, including adamellite, granite, granodiorite, diorite, tonalite and gabbro plutons (mid-Cretaceous), moreover basic and acid hypabyssal dykes (?Upper Cretaceous). The relationships between these rock-units are shown in geological map and sketches of field exposures.

The paper presents a catalogue, with description, detailed map location and references to first publications, of new place names introduced mainly during the Polish Geodynamic Expeditions to West Antarctica, 1984-1991. In the South Shetland Islands, new place names were introduced in parts of King George Island and Deception Island (Some new names for Admiralty Bay, King George Island and Penguin Island, introduced prior to 1984 but not yet formally described, are also included here). In Antarctic Peninsula, new place names have been introduced at Hope Bay (Trinity Peninsula), Arctowski Peninsula-Andvord Bay (Danco Coast/Gerlache Strait) and Paradise Harbour (Danco Coast).

During the Polish Geodynamic Expeditions to West Antarctica, 1984-1991, led by A. Guterch, the scientific research of the geological group (leader K. Birkenmajer) included stratigraphic, sedimentological, petrological, tectonic, volcanological and Quaternary geology studies. They were caried out mainly in the area of Antarctic Peninsula, Palmer Archipelago and South Shetland Islands (the results from King George Island have been reviewed separately, in 1996). The major scientific archievements are: (1) introduction of formal lithostrati-graphical standards, recognition of tectonic structure, and sedimentological characteristics of the Trinity Peninsula Group (?Upper Permian-Triassic) metasediments (Antarctic Peninsula: Hope Bay and Paradise Harbour; Livingston Island: Hurd Peninsula); (2) elaboration of Late Mesozoic-TTertiary magmatic successions (Antarctic Peninsula Volcanic Group and Andean Intrusive Suite) on northern Antarctic Peninsula (Hope Bay; Arctowski Peninsula; Paradise Harbour - Gerlache Strait); (3) together with geophysical group: elaboration of lithospheric transect from South Shetland Islands to Antarctic Peninsula; (4) elaboration of Late Cenozoic evolution stages of the Bransfield Basin and Rift, as based on geological and palaeontological record; (5) introduction of a revised volcanostratigraphic standard, and reconstruction of evolution stages, of the Deception Island volcano (South Shetland Islands); (6) reconstruction of the Holocene history in some areas of Antarctic Peninsula (Hope Bay) and South Shetland Islands (King George Island). The results of palaeontological and sedimentological research on Seymour and Cockburn islands (NE Antarctic Peninsula) were presented separately.