K-Ar dating of basic intrusions at Bellsund, Spitsbergen, Svalbard Krzysztof BIRKENMAJER1, Krzysztof P. KRAJEWSKI2, Zoltán PÉCSKAY3 and Marek W. LORENC4
1 Instytut Nauk Geologicznych PAN, Senacka 1, 31-002 Kraków, Poland
2 Instytut Nauk Geologicznych PAN, Twarda 51/55, 00-818 Warszawa, Poland
3 Institute of Nuclear Research, Hungarian Academy of Sciences,
Bem tér. 18c, 4001 Debrecen, Hungary
4 Instytut Architektury Krajobrazu, Uniwersytet Przyrodniczy we Wrocławiu,
pl. Grunwaldzki 24a, 50-363 Wrocław, Poland
Abstract: Nine samples of basic (dolerite, gabbro) intrusions collected at Bellsund, South Spitsbergen, have been K-Ar dated. Three dates, between 87.8 and 102.9 Ma, obtained from dolerite sills which intrude Carboniferous and Permian deposits in Van Keulenfjorden point to a Cretaceous age of intrusive activity (Diabasodden Suite). The K-Ar dates obtained from dolerite and gabbro which intrude Upper Proterozoic metasedimentary terrane of Chamberlindalen form two groups: the dates between 97.1 and 178.6 Ma point to a Mesozoic age of the intrusions (Diabasodden Suite); the dates from a tectonized gabbroid (280.9–402.0 Ma) might point to a Late Palaeozoic age of the intrusion. No K-Ar dates which would indicate a Proterozoic age of the basic intrusions were obtained.
Key words: Arctic, Spitsbergen, dolerite intrusions, Mesozoic, Late Palaeozoic, K-Ar dating.
POLISH POLAR RESEARCH VOL. 31 No. 1, pp. 17–32
Spatial information on total solar radiation: Application and evaluation of the r.sun model
for the Wedel Jarlsberg Land, Svalbard Maciej KRYZA1, Mariusz SZYMANOWSKI2, Krzysztof MIGAŁA1 and Małgorzata PIETRAS1
1 Uniwersytet Wrocławski, Instytut Geografii i Rozwoju Regionalnego, Zakład Klimatologii i Ochrony Atmosfery, Kosiby 6/8, 51-670 Wrocław, Poland
2 Uniwersytet Wrocławski, Instytut Geografii i Rozwoju Regionalnego, Zakład Kartografii, pl. Uniwersytecki 1, 50-137 Wrocław, Poland
Abstract: The results of the application and evaluation of the r.sun model for calculation of the total solar radiation for the Wedel Jarlsberg Land (SW Spitsbergen) are presented. Linke Turbidity Factor (LTF), which is the obligatory parameter for direct and diffused radiation calculations with the r.sun model, is derived here with the empirical formula and meteorological measurements. Few different approaches for calculation of LTF are presented and tested. The r.sun model results, calculated with these various LTF, are evaluated through comparison with total solar radiation measurements gathered at Polish Polar Station. The r.sun model is found to be in good agreement with the measurements for clear sky conditions, with the explained variance (R2) close to 0.9. Overall, the model slightly underestimates the measured total radiation. Reasonable results were calculated for the cloudiness condition up to 2 octas, and for these r.sun model can be considered as a reliable and flexible tool providing spatial data on solar radiation for the study area.
Reproduction and genetic structure of a freshwater crustacean Lepidurus arcticus from Spitsbergen Barbara WOJTASIK* and Magdalena BRYŁKA-WOŁK
Katedra Genetyki, Uniwersytet Gdański, Al. Piłsudskiego 46, 81-378 Gdynia, Poland;
Polska Stacja Polarna PAN, 9177-Hornsund, Svalbard
(* corresponding author)
Abstract: Genetic variability of two populations of Arctic freshwater crustacean Lepidurus arcticus (Crustacea, Notostraca) occuring in small tundra reservoirs near the Polish Polar Station in Hornsund (Spitsbergen) was studied. The allozyme polimorphism analysis of 11 enzyme systems indicates a considerable distinctness and genetically heterogeneous character of the populations of L. arcticus inhabiting freshwater reservoirs of similar hydrological conditions situated close to each other (2 km). Our research revealed a complicated and genetically heterogeneous character of the populations. Three hypotheses about genetic structure and type of reproduction were tested: hypothesis M – the free transfer without assigning a clone for particular reservoir and the lack of double mutations; hypothesis I – separation of individuals between reservoirs and the possibility of double mutations; hypothesis S – presence of partial sexual reproduction in the population, probably with males. In conclusion participation of males in reproduction is probable, despite their presence was not recorded in our study. Males usually occur in low numbers or not every year. The populations' clonal structure as well as the genetic diversity typical of species reproducing sexually was observed. The Hardy-Weinberg genetic equilibrium is maintained as new clonal lines appear due to the genetic diversity increasing incidentally as a result of sexual reproduction.
Key words: Arctic, Svalbard, Crustacea, Lepidurus arcticus, parthenogenesis, males, allozymes.
POLISH POLAR RESEARCH VOL. 31 No. 1, pp. 45–60
Human impact upon the environment in the vicinity of Arctowski Station, King George Island, Antarctica Katarzyna J. CHWEDORZEWSKA and Małgorzata KORCZAK
Zakład Biologii Antarktyki, Polska Akademia Nauk, Ustrzycka 10/12, 02-141 Warszawa, Poland
Abstract: During thirty three expeditions to the Polish Arctowski Antarctic Station significant influences of human activity upon the environment have been recorded. Introductions of alien species, shifts of bird and seal breeding areas and decreases in both bird and seal populations, are the most obvious effects of human pressure. Though numbers of visits by tourists have increased during this period, impacts from expeditioners appear to be the main cause of changes. In particular, increasing numbers and mobility of summer groups at the station are the likely most influential factors.
Key words: Antarctica, King George Island, human impact.
POLISH POLAR RESEARCH VOL. 31 No. 1, pp. 61–82
Benthic foraminifera from West Antarctic fiord environments: An overview Wojciech MAJEWSKI
Instytut Paleobiologii PAN, Twarda 51/55, 00-818 Warszawa, Poland
Abstract: After several years of research, the foraminiferal fauna of Admiralty Bay (King George Island, South Shetland Islands) has become the most studied fiord in West Antarctica with respect to foraminifera. As such, it provides actualistic data for better understanding of paleoenvironmental records from this dynamically changing area. Over a few years, the bay was systematically sampled down to 520 m water depth, for multi-chambered and monothalamous benthic foraminifera, including soft-walled allogromiids often overlooked in former studies. Altogether, 138 taxa were identified, and three new taxa described. This paper aims to integrate these results, put them into a broader perspective, and supplement them with information that was not presented to date. Most notably, a record of the vertical distribution of Rose Bengal stained foraminifera below the sediment surface and the proportions of soft and robustly-testate forms at different sites are described.
Key words: Antarctica, King George Island, Admiralty Bay, Foraminifera.
POLISH POLAR RESEARCH VOL. 31 No. 1, pp. 83–99
Phymatoderma melvillensis isp. nov. and other trace fossils from the Cape Melville Formation (Lower Miocene)
of King George Island, Antarctica Alfred UCHMAN1 and Andrzej GAŹDZICKI2
1 Instytut Nauk Geologicznych, Uniwersytet Jagielloński, Oleandry 2a, 30-063 Kraków, Poland
2 Instytut Paleobiologii, Polska Akademia Nauk, Twarda 51/55, 00-818 Warszawa, Poland
Abstract: 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) environment. Deep marine crab Antarctidromia inflata Förster, 1985, has been found in Thalassinoides isp. The tracemaker (?crustacean) of Phymatoderma melvillensis re-reworked pelletal sediments probably during times of food deficiency.
Key words: Antarctica, King George Island, Cape Melville Formation, ichnofossils, Miocene, glacio-marine strata.