Polish Polar Research

New coral taxa Tetraporinus siedlecka sp. n. and Roemeripora aspinosa major ssp. n. are erected from the Lower Permian (Sakmarian and Artinskian) Treskelodden Formation of Hornsund area, Spitsbergen and Syringopora sp. similar to S. subreticulata Nowiński, 1991 are described. Studies on stable isotope ratios of carbon and oxygen in the skeletons of tabulate and rugose corals from Hyrnefjellet and Treskelen areas show that these organism did not frac­tion the isotopes to much. The differences in isotope fractionation, both for carbon and oxygen, reached 2 ‰ comparable to the concurring brachiopods, accepted as reference level.

The Marhegda Bed is a carbonate-dominated Uthostratigraphic unit occurring locally at base of the Middle-Late Jurassic organic-rich sequence of the Agardhfjellet Formation in Spitsbergen, Svalbard. It has been interpreted to represent oolitic limestone facies deposited during an initial stage of Late Jurassic transgression. Petrographic, major element geochemical, and stable carbon and oxygen isotopic data presented in this paper indicate that this litho-stratigraphic unit is not a depositional limestone, but a diagenetic cementstone band originated in organic-rich sediment containing glauconite pellets and phosphatic ooids and grains. Two ep­isodes of carbonate diagenesis, including early precipitation of siderite and burial precipitation of ankerite, have contributed to the development of this cementstone. Extensive siderite precipi­tation occurred at sedimentary temperatures in nearsurface suboxic environment in which microbial reduction of ferric iron was the dominant diagenetic process. Precipitation of ankerite occurred at temperatures of about 80-100°C in burial diagenetic environment overwhelmed by thermal decarboxylation processes. Formation of ankerite was associated with advanced alteration of glauconite, dissolution of apatite and precipitation of kaolinite.

During four Polish Geodynamical Expeditions to West Antarctica between 1979 and 1991, seismic measurements were made along 21 deep refraction profiles in the Bransfield Strait and along the coastal area of Antarctic Peninsula using explosion sources. Recordings were made by 16 land stations and 8 ocean bottom seismometers. Good quality recordings were obtained up to about 250 km distance. This allowed a detailed study of the seismic wave field and crustal structure. Three-dimensional tomographic inversion was carried out using first arriv­als from the complete data set including off-line recordings. As a result, we obtained a 3-D model of the P-wave velocity distribution in the study area. In the area adjacent to the Antarctic Peninsula coast, sedimentary cover of 0.2 to 3 km thickness was found, whereas in the shelf area and in the Bransfield Strait sedimentary basins with thickness from 5 to 8 km were observed. In the Bransfield Strait a high velocity body with Vp > 7.5 km/s was found at 12 km depth. The use of the off-line data allowed for determination of the horizontal extent of the body. The thickness of the crust varies from more than 35-40 km in the coastal area south of the Hero Fracture Zone to 30-35 km in the area of Bransfield Strait and South Shetland Islands and about 12 km in the Pacific Ocean NW of South Shetland Islands.

Body size is an important measure in biology and especially in paleobiology. With respect to fossil penguins from the Eocene La Meseta Formation of Seymour Island (West Antarctica) the overall size has to be judged from the dimensions of single bones. The analysis based on selected measurements of hind limb bones from the Polish collection of Eocene Ant­arctic penguins yielded results supporting predictions published formerly. Estimated body masses and lengths indicate that mean interspecific body size of extinct Antarctic Spheniscidae exceeded that of Recent species.

In total, 18 species and larval forms of endoparasitic worms were found in 19 newly examined notothenioid fishes of three species, Trematomus hansom, Notothenia coriiceps and Chionodraco hamatus, caught off Adelie Land. One digenean species, Neolepidapedon trema-tomi, was recorded in this area for the first time. A total list of endoparasitic worms prepared by Zdzitowiecki etal. (1998) increased from 20 to 21 species and larval forms and concerns 11 deter­mined and one determined species of Digenea (the most diverse group), three larval forms of Cestoda, three species (one identified only to genus) of Acanthocephala, two species (one in the larval stage) and one larval form of Nematoda. All these species and forms, with the exception of the indetcrmined digenean, occur also in the deep Antarctica, in the Ross Sea and/or in the Weddell Sea. The prevalence and relative density of infection with each parasite in three host species is given based on summarized previous and new data.