Solitary corals of the genus Flabellum are described from the Lower Oligocene glaciomarine strata of the Polonez Cove Formation of King George Island, West Antarctica. This is the oldest record of the genus from Antarctica.
Herve Cove, a small, shallow and partly isolated basin, is strongly influenced by glacial freshwater inlfow, bringing significant amount of mineral suspension. Its mean annual content amounted up to 46 mg dm-3. Sea anemone (Edwardsia sp.), bivalves (Yoldia eightsi, Laternula elliptica and Mysella sp.), amphipods (mostly Cheirimedon femoratus) a well as some species of polychaetes constituted almost 95% of zoobenthos biomass and 90% of abundance. Four different assemblages of benthic invertebrates, with total biomass ranging from 0.002 kg m-2 up to 1.7 kg m-2, were distinguished in this relatively small (about 12 ha) area. It seems that the freshwater impact influences the composition of an assemblage occurring close to the edge of a glacier. Relatively rich crustacean fauna was encountered in the shallow part of the cove near its entrance. Almost complete lack of echinoderms in Herve Cove, that are common in the shallow Antarctic sublittoral, should also be noted. Macrozooplankton of Herve Cove was dominated by Copepoda. The most frequent and abundant species were: Oithona similis, Ctenocalanus citer and Metridia gerlachei. Far less numerous Chaetognatha represented by three species, Ostracoda, Polychaeta, Pteropoda and Siphonophora constituted only 2.5% of all planktonie animals collected.
The paper presents the results of taxonomical investigation of the genus Cladonia Hill ex P. Browne from King George Island . Individuals belonging to this lichen genus were studied using methods of classical herbarium taxonomy supported by chemical analysis. Fourteen species have been recognized in the study area, with C. asahinae J.W. Thomson being reported from King George Island for the first time, and C. cervicornis subsp. mawsonii reported as new for the South Shetland Islands. The occurrence of C. cariosa is confirmed for the Antarctic region. The diagnostic characters, ecology and important remarks referring to particular species are briefly presented. An updated key for identification of the species from King George Island and neighbouring islands of South Shetlands is included.
This paper presents some preliminary data on the quantitative distribution of Tanaidacea in Admiralty Bay, mainly in its Ezcurra Inlet. On the soft bottom of this inlet, and especially its small glacial lagoon, Herve Cove, the highest abundance but the lowest species richness of Tanaidacea was found. In the central basin of Admiralty Bay, much higher species richness was observed along with much lower tanaid abundance.
Objects that have come within the inventory are the effect of whaling activity carried out in the region of South Shetland Islands in the first half of the twentieth century. They include mainly bones of hunted animals, rarely wooden or metal objects, part of which may be related to the whaling industry. In this paper the areas of particular accumulation of these objects have been determined, and the attempts to explain the reasons for such accumulations have been made. In addition, certain suggestions for further investigations into whaling activity in the South Shetland Islands region have been put forward. During the work 158 large fragments of whale skulls, among others, have been inventoried. The total number of individuals whose preserved relics have been explored within the surveyed sections of the Admiralty Bay shores has been estimated to be 210-230.
Molluscan fossils accompanied by familiar SSF have been recovered from Early Cambrian limestone erratics in the Early Miocene glaciomarine Cape Melville Formation of King George Island, West Antarctica. The molluscan fauna comprises the hyoliths Conotheca, Microcornus, Parkula, Hyptiotheca, Hyolithes, the helcionelloids ?Pararacornus, Yochelcionella, Anabarella, the low dextrally coiled Pelagiella and the high helically coiled Beshtashella, as well as the problematic mollusc Cupitheca. Most of described species are recorded here for the first time from Antarctica. The lithological and fossil contents of the erratics are almost the same as from autochthonous successions the Shackleton Limestone in the Argentina Range and Transantarctic Mountains. Early Cambrian outcrops around the Weddell Sea are a probable source of the erratic boulders. The Antarctic fauna is very similar to that from uppermost Botomian and Toyonian carbonate deposits in the Cambrian Basins of South Australia. These faunal and facies similarities between Antarctica and Australia confirm their neighbouring position and common biotic and basin evolution on the Cambrian Gondwana margin.
Radiometric and geochemical studies were carried out at Red Hill in the southern part of King George Island (South Shetland Islands, northern Antarctic Peninsula) on the Bransfield Strait coast. The rock succession at Red Hill has been determined to represent the Baranowski Glacier Group that was previously assigned a Late Cretaceous age. Two formations were distinguished within this succession: the lower Llano Point Formation and the upper Zamek Formation. These formations have stratotypes defined further to the north on the western coast of Admiralty Bay. On Red Hill the Llano Point Formation consists of terrestrial lavas and pyroclastic breccia; the Zamek Formation consist predominantly of fine to coarse tuff, pyroclastic breccia, lavas, tuffaceous mud− , silt−, and sandstone, locally conglomeratic. The lower part of the Zamek Formation contains plant detritus (Nothofagus , dicotyledonous, thermophilous ferns) and numerous coal seams (vitrinitic composition) that confirm the abundance of vegetation on stratovolcanic slopes and surrounding lowlands at that time. Selected basic to intermediate igneous rocks from the succession have been analysed for the whole−rock K−Ar age determination. The obtained results indicate that the Red Hill succession was formed in two stages: (1) from about 51–50 Ma; and (2) 46–42 Ma, i.e. during the Early to Middle Eocene. This, in combination with other data obtained from other Baranowski Glacier Group exposures on western coast of Admiralty Bay, confirms the recently defined position of the volcano−clastic succession in the stratigraphic scheme of King George Island. The new stratigraphic position and lithofacies development of the Red Hill succession strongly suggest its correlation with other Eocene formations containing fossil plants and coal seams that commonly occur on King George Island.
New evidence of Eocene preglacial environments has been found on the southern coast of Ezcurra Inlet on King George Island, South Shetland Islands, West Antarctica. Plant remains (trunks, leaves, detritus) and carbonaceous seams and beds occur in sedimentary strata in a 4 km long Cytadela outcrop of the Point Thomas Formation. They are an evidence for the presence and diversity of terrestrial vegetation in the northern Antarctic Peninsula region. The forests were composed mostly of Podocarpaceae– Araucaria – Nothofagus , with an undergrowth of hygrophilous and thermophilous ferns, and grew on volcanic slopes and surrounding lowland areas of King George Island during breaks in volcanic activity. The succession that crops out at Cytadela provides a record of changing climatic conditions from a warm and wet climate with extensive vegetation to a much drier climate with limited vegetation and ubiquitous weathering of volcanic bedrock. The geochemical indices of weathering (CIA, PIA and CIW) have narrow and relatively high value ranges (76–88), suggesting moderate to high chemical weathering under warm and humid climate conditions. The decrease in humidity and the decline in plant life through the succession can be related to the gradually cooling climate preceding development of the Oligocene ice cover across the Antarctic continent.
Luticola muticopsis is a characteristic species of polar and subpolar regions. Its morphological variability is not yet precisely described. In the investigated population the cells from capitate to shortened, flat rounded tips were observed. The range of dimensions of specimens was 8.8-40.6 μm x 5.5-17.6 μm, striae 11-22/10 μm; this range considerably exceeded that found in holotype diagnosis.
Trace fossils Phymatoderma melvillensis isp. nov., Thalassinoides isp., ?Nereites isp. and Planolites isp. are reported from the glacio−marine sediments of the Cape Melville Formation (Lower Miocene) of King George Island, West Antarctica. Their occurrence and strong bioturbation of sediments point to an offshore or deeper (outer shelf or upper slope) en− vironment. Deep marine crab Antarctidromia inflata Förster, 1985, has been found in Thalassinoides isp. The tracemaker (?crustacean) of Phymatodermamelvillensis re−reworked pelletal sediments probably during times of food deficiency.
Pyrite framboids occur in loose blocks of plant−bearing clastic rocks related to volcano−sedimentary succession of the Mount Wawel Formation (Eocene) in the Dragon and Wanda glaciers area at Admiralty Bay, King George Island, West Antarctica. They were investigated by means of optical and scanning electron microscopy, energy−dispersive spectroscopy, X−ray diffraction, and isotopic analysis of pyritic sulphur. The results suggest that the pyrite formed as a result of production of hydrogen sulphide by sulphate reducing bacteria in near surface sedimentary environments. Strongly negative #2;34SVCDT values of pyrite (−30 – −25 ‰) support its bacterial origin. Perfect shapes of framboids resulted from their growth in the open pore space of clastic sediments. The abundance of framboids at cer− tain sedimentary levels and the lack or negligible content of euhedral pyrite suggest pulses of high supersaturation with respect to iron monosulphides. The dominance of framboids of small sizes (8–16 μm) and their homogeneous distribution at these levels point to recurrent development of a laterally continuous anoxic sulphidic zone below the sediment surface. Sedimentary environments of the Mount Wawel Formation developed on islands of the young magmatic arc in the northern Antarctic Peninsula region. They embraced stagnant and flowing water masses and swamps located in valleys, depressions, and coastal areas that were covered by dense vegetation. Extensive deposition and diagenesis of plant detritus in these environments promoted anoxic conditions in the sediments, and a supply of marine and/or volcanogenic sulphate enabled its bacterial reduction, precipitation of iron mono− sulphides, and their transformation to pyrite framboids.
Carotenoids in six species of the lichens from Antarctica (Xanthoria eleguns, Caloplaca regalis, Usnea antarctica, U. fasciata, Himantormia lugubris and Ramalina terebrata) have been investigated by means of column and thin — layer chromatography. The following carotenoids were found: β-carotene, α- and β-cryptoxanthin, canthaxanthin. lycophyll, lycoxanthin, lutein, lutein epoxide, zeaxanthin, antheroxanthin, adonixanthin, diatoxanthin, rhodoxanthin, rhodoxanthm derivative, α-doradexanthin, astaxanthin, astaxanthin ester, mutatochrome, mutatoxanthin and cryptoflavin. Most frequently occurred β-carotene, β-cryptoxanthin, lutein epoxide, zeaxanthin and mutatoxanthin. The total carotenoid content ranged from 10.242 (Ramalina terebrata) to 18.700 mg/g dry weight (Himantormia lugubris) in October and from 4.765 (Ramalina terebrata) to 12.462 mg/g dry weight (Caloplaca regalis) in February.
In the material collected in 26 stations along the course of three creeks in the vicinity of Polish Antarctic Station 183 taxa of algae have been identified: 25 of Cyanophyta, 123 of Bacillariophyceae, 2 of Xanthophyceae, 2 of Chrysophyceae and 31 of Chlorophyta. The highest species diversity was found in the algal community in Creek II (132 taxa), the second place was occupied by the "Petrified Forest Creek" (97 taxa), and the least diversified algal community was that from the "Ornithologists' Creek" (73 taxa).
A topographic map 1:12,500 scale of the SSSI No. 8 and the Arctowski Station region was prepared during the XXV Polish Polar Expedition (2000/2001) organized by the Department of Antarctic Biology, Polish Academy of Sciences. The map documents geomorphological changes which took place during the last 20 years. Several new place names have been introduced for the SSSI No. 8 area.