Maastrichtian planktic foraminifera of the South Atlantic Ocean

Stratigraphic, faunal and isotopic analyses of the Maastrichtian at DSDP sites 525A and 21 in the South Atlantic reveal a planktic foraminiferal fauna characterized by two major events, an early late Maastrichtian diversification and end-Maastrichtian mass extinction. Both events are accompanied by major changes in climate and productivity. The diversification event which occurred in two steps between 70.5 and 69.1 Ma increased species richness by a total of 43% and coincided with the onset of major cooling in surface and bottom waters and increased surface productivity. The onset of the terminal decline in Maastrichtian species richness began at 67.5 Ma and the first significant decline in surface productivity occurred at 66.2 Ma, coincident maximum cooling to 13°C in surface waters and the reduction of the surface-to-deep temperature gradient to less than 5°C. Major climatic and moderate productivity changes mark the mass extinction and the last 500 kyr of the Maastrichtian. Between 200 and 400 kyr before the K-T boundary surface and deep waters warmed rapidly by 3-4°C and cooled again during the last 100 kyr of the Maastrichtian. Surface productivity decreased only moderately across the K-T boundary. Species richness began to decline during the late Maastrichtian cooling and by K-T boundary time, the mass extinction had claimed 66% of the species. Viewed within the context of Maastrichtian climate and productivity changes, the K-T mass extinction could have resulted from extreme environmental stress even without the addition of an extraterrestrial impact.

Relative contents of principal diatom groups in suspended matter and surface layer bottom sediments from the Indian Ocean

Data on relative contents of principal diatom groups in suspended matter collected by a separator on the way of the ship and in bottom sediments from different areas of the Indian Ocean are presented in the paper.

The hydropolyp fauna of the Red Sea area

46 hydropolyp species of 28 genera and 10 families were sampled during the "Meteor" passage 1964/65 (IIOE) through the Red Sea and its northern and southern exits and on the occasion of several ecological investigations of 29 selected coral reef sections of the central Red Sea and the Gulf of Aqaba. These collections comprise 128 single records of hydropolyp species. Three species and two genera each with one species are doubtful. 25 species, seven genera, one family and one subfamily, together from 49 records have not previously been found in the Red Sea and its exits. Including these newly reported species, the total list increases from 64 species and 112 records to 89 species and 240 single records and 51 additional ones. Scanning microscopical photos, made for the first time for the illustration of the hydropolyps, have been shown to be suitable for a better characterization and diagnosis of the species. Qualified results on the reasons for the horizontal distribution of the species known from the Red Sea area cannot be given because of the low number of samples sporadically distributed through the whole area. In contrast with this fact, the vertical spread of the species sampled seems primarily to be regulated by water exchange and light intensity. For example, four species of hydropolyps are excellent indicators of certain abiotic factors or combinations of them: Gymnangium eximium reacts extremely stenophote-photophobe-rheophil, Eudendrium ramosum moderately stenophote-photophobe-rheophobe, Lytocarpus philippinus moderately stenophote-photophil-rheophil, and Halocordyle disticha var. australis extremely stenophote-photophil but moderately rheophil. Other species have been found throughout all the light zones. Combined with the small size of their colonies their euryphotic behaviour does not allow their use as indicator species.

Planktonic foraminifera and their stable isotope record of MICNESS samples off Cape Cod

Monthly samples of stratified plankton tows taken from the slope waters off Cape Cod nearly 25 years ago are used to describe the seasonal succession of planktonic foraminifera and their oxygen isotope ratios. The 15°C seasonal cycle of sea surface temperature (SST) accounts for a diverse mixture of tropical to subpolar species. Summer samples include various Globigerinoides and Neogloboquadrina dutertrei, whereas winter and early spring species include Globigerina bulloides and Neogloboquadrina pachyderma (dextral). Globorotalia inflata lives all year but at varying water depths. Compared with the fauna in 1960-1961 (described by R. Cifelli), our samples seem warmer. Because sea surface salinity varies little during the year, d18O is mostly a function of SST. Throughout the year, there are always species present with d18O close to the calculated isotopic equilibrium of carbonate with surface seawater. This raises the possibility that seasonality can be estimated directly from the range of d18O in a sediment sample provided that the d18O-salinity relationship is the same as today.

Chemical composition of bottom sediments from the northern part of the Deryugin Trough, Sea of Okhotsk

Distribution trace element contents in the upper (up to 5 m) Holocene-Upper Pleistocene sediment layer along the northern and southern sublatitudinal profiles in the northern part of the Deryugin Trough is discussed. Mathematical processing of chemical analysis data has been made. On the basis of the cluster analysis 16 elements have been combined into 5 geochemical groups. Two of them (1 - Ag-Mo group and 2 - Mn-Ba-Ni-Sr group) were considered in detail. Analysis of Ag and Mo distributions in the sediments and findings of molybdenite permitted to conclude that enrichment of the sediments by these elements resulted from edaphic washing of magmatic rocks containing Ag-Mo mineralization and probably located on the northwestern slope of the Deryugin trough. The second geochemical group is most likely connected with hydrothermal barite mineralization found in the northeastern part of the Deryugin trough. Considering Mn distribution in bottom sediment cores supply of Mn was pulsating. This allows concluding that during Holocene - Late Pleistocene three cycles of hydrothermal activity occurred in the Deryugin Trough, and the most intensive one was in Holocene.

Composition of organic matter from samples of massive sulfides, bottom sediments, and seawater collected within the Logachev and Broken Spur hydrothermal fields, Mid-Atlantic Ridge

Lipid components of hydrothermal deposits from the unusual field at 14°45'N MAR and from the typical field at 29°N MAR were studied. For the first time mixed nature of organic matter (OM) from hydrothermal sulfide deposits was established with use of biochemical, gas chromatographic, and molecular methods of studies. In composition of OM lipids of phytoplankton, those of chemosynthesis bacteria and non-biogenic synthesis lipids were determined. Specific conditions of localization of sulfide deposits originated from ''black smokers'' (reducing conditions, absence of free oxygen, presence of reduced sulfur preventing OM from decomposition) let biogenic material, including bacterial one, be preserved in sulfide deposits. The hydrothermal system at 14°45'N MAR is characterized by geological, geochemical and thermodynamic conditions allowing abiogenic synthesis of methane and petroleum hydrocarbons. For sulfide deposits at 29°N and other active hydrothermal fields known at MAR, abiogenic synthesis of hydrocarbons occurs in lower scales.

Grain size composition of marine and river bottom sediments

According to average grain size parameters (Kd, Kd1) recent sediments from the northern Caspian Sea and the Barents Sea shelf are similar, while sediments from the Norwegian Sea are closer to their counterparts of the World Ocean. Seaward content of subcolloidal (<0.001 mm) size fraction increases against the background of decreasing proportions of coarse- and medium-grained pelite (<0.01 mm) material.

Hydrocarbons in surface layer bottom sediments from the North Dvina Riverand the southern part of the Dvina Bay, White Sea

Analysis of molecular composition of alkanes in bottom sediments of the southern part of Dvina Bay (White Sea) in October 2001 revealed the following main peculiarities of hydrocarbon behavior in the estuary: dominating of high molecular C23-C45 compounds and irregular distribution of hydrocarbons in bottom sediments as a result of high sedimentation rate and active hydrodynamics in the studied area.

Um estudo descritivo preliminar dos sememas das línguas parintintin e zoró para animais da fauna brasileira

No Brasil, existem aproximadamente 200 línguas indígenas, dessas algumas nao foram descritas. Grosso modo, há dois troncos linguísticos (Tupi e Macro Jê) e existem famílias linguísticas ou línguas que nao apresentam semelhanças suficientes para serem agrupadas nos troncos linguísticos conhecidos. O objetivo deste trabalho é apresentar um estudo descritivo e contrastivo em relaçao aos sememas que descrevem os animais da fauna brasileira das línguas Zoró e Parintintin baseado nos conceitos onomasiologicos. Com relaçao ao aporte teórico adotado, apoiamo-nos em Babini (2001), Barbosa (2002), Lisboa (2008) e Kurovski (2009). A metodologia consiste em pesquisa bibliográfica e comparaçao entre sememas das duas línguas com a língua portuguesa. Podemos mencionar que há elevado grau de diferenciaçao entre o português e as duas línguas estudadas. Como exemplo, pode-se mencionar que para o falante do português os sememas para "peixe pintado" seriam: "peixe e água doce", "peixe de carne saborosa", "peixe de couro" enquanto que o semema da língua zoró para o mesmo peixe seria "causa a hepatite". No caso do parintintin os sememas foram avaliados a partir do sistema exogâmico, que divide todos os seres e objetos em duas categorias: Myty e Kwandu (pássaros da Amazônia brasileira), tal classificaçao é levada em consideraçao na escolha do alimento que será consumido. Dessa forma, verificou-se que os sememas indígenas para animais representam, primordialmente, fonte de alimento e sobrevivência, e, também, estao correlacionados às questoes cosmogônicas e culturais. Por sua vez, os sememas de animais para o homem lusófono focam os aspectos visual e preservacionista. Por fim, cabe salientar que o estudo é preliminar e os dados levantados serao empregados para a construçao de um glossário onomasiológico da fauna brasileira

Isotopic composition of bottom and interstitial waters in the area of gas plumes, Sea of Okhotsk

Data on isotopic composition of interstitial and bottom waters collected in an area of gas hydrate occurrence in the Sea of Okhotsk are presented. Investigations indicate that heavy isotopes of oxygen and hydrogen are used in generation of gas hydrate, so that isotopic composition of its water of constitution is: d18O = +1.9 per mil, d2H = +23 per mil (relative to SMOW). Production of authigenic carbonates results in isotopic exchange with interstitial water, which in turn alters its isotopic composition by an increase in d18O. Bottom waters are isotopically light relative to the SMOW standard and to the average isotopic composition of interstitial waters in the area of gas hydrate occurrence in study.

High-resolution in situ oxygen microprofiles, porewater and solid phase geochemistry from the Crimean shelf (Black Sea) from Maria S. Merian cruise MSM15/1

The outer western Crimean shelf of the Black Sea is a natural laboratory to investigate effects of stable oxic versus varying hypoxic conditions on seafloor biogeochemical processes and benthic community structure. Bottom-water oxygen concentrations ranged from normoxic (175 µmol O2/L) and hypoxic (< 63 µmol O2/L) or even anoxic/sulfidic conditions within a few kilometers' distance. Variations in oxygen concentrations between 160 and 10 µmol/L even occurred within hours close to the chemocline at 134 m water depth. Total oxygen uptake, including diffusive as well as fauna-mediated oxygen consumption, decreased from 15 mmol/m**2/d on average in the oxic zone, to 7 mmol/m**2/d on average in the hypoxic zone, correlating with changes in macrobenthos composition. Benthic diffusive oxygen uptake rates, comprising respiration of microorganisms and small meiofauna, were similar in oxic and hypoxic zones (on average 4.5 mmol/m**2/d), but declined to 1.3 mmol/m**2/d in bottom waters with oxygen concentrations below 20 µmol/L. Measurements and modeling of porewater profiles indicated that reoxidation of reduced compounds played only a minor role in diffusive oxygen uptake under the different oxygen conditions, leaving the major fraction to aerobic degradation of organic carbon. Remineralization efficiency decreased from nearly 100 % in the oxic zone, to 50 % in the oxic-hypoxic zone, to 10 % in the hypoxic-anoxic zone. Overall, the faunal remineralization rate was more important, but also more influenced by fluctuating oxygen concentrations, than microbial and geochemical oxidation processes.

Ostracode fauna of sediment core GIK23414-9 in the northeast Atlantic

Sediment core M23414 from the Rockall Plateau (North Atlantic) covering the last two climatic cycles, marine isotope stages (MIS) 7 to 1, was investigated for glacial-interglacial variations in the deep-sea benthic ostracode fauna. A highly diversified ostracode fauna including 98 species was found. Two climate-related assemblages were identified, associated with interglacial and peak glacial periods, respectively. The 'interglacial' group occurs during the end of MIS 7, 5 and 1 and is composed of the genera Henryhowella, Pelecocythere, Echinocythereis, Cytherella, Bradleya, Aversovalva and Eucytherura. The 'glacial' group consists of the genera Acetabulastoma (which is known as 'sea ice indicator' in the modern Arctic Ocean), Polycope, Bythoceratina, ?Rhombobythere, and some species possibly belonging to the genus Pseudocythere and is found during MIS 6, 4 and 2. These longer-term variations within the ostracode fauna seem related to the particular glacial and interglacial climate conditions that affected both deep-water production as well as primary production in the surface waters. However, a detailed comparison of ostracode abundances with the occurrence of events marked by increased ice-rafted debris reveals also much shorter-term climate related changes in the ostracode fauna. Thus, the temporal fluctuations within ostracode assemblages reflect long- and short-term alterations of the deep-sea environment that are clearly linked to climate changes.

Um estudo descritivo preliminar dos sememas das línguas parintintin e zoró para animais da fauna brasileira

No Brasil, existem aproximadamente 200 línguas indígenas, dessas algumas nao foram descritas. Grosso modo, há dois troncos linguísticos (Tupi e Macro Jê) e existem famílias linguísticas ou línguas que nao apresentam semelhanças suficientes para serem agrupadas nos troncos linguísticos conhecidos. O objetivo deste trabalho é apresentar um estudo descritivo e contrastivo em relaçao aos sememas que descrevem os animais da fauna brasileira das línguas Zoró e Parintintin baseado nos conceitos onomasiologicos. Com relaçao ao aporte teórico adotado, apoiamo-nos em Babini (2001), Barbosa (2002), Lisboa (2008) e Kurovski (2009). A metodologia consiste em pesquisa bibliográfica e comparaçao entre sememas das duas línguas com a língua portuguesa. Podemos mencionar que há elevado grau de diferenciaçao entre o português e as duas línguas estudadas. Como exemplo, pode-se mencionar que para o falante do português os sememas para "peixe pintado" seriam: "peixe e água doce", "peixe de carne saborosa", "peixe de couro" enquanto que o semema da língua zoró para o mesmo peixe seria "causa a hepatite". No caso do parintintin os sememas foram avaliados a partir do sistema exogâmico, que divide todos os seres e objetos em duas categorias: Myty e Kwandu (pássaros da Amazônia brasileira), tal classificaçao é levada em consideraçao na escolha do alimento que será consumido. Dessa forma, verificou-se que os sememas indígenas para animais representam, primordialmente, fonte de alimento e sobrevivência, e, também, estao correlacionados às questoes cosmogônicas e culturais. Por sua vez, os sememas de animais para o homem lusófono focam os aspectos visual e preservacionista. Por fim, cabe salientar que o estudo é preliminar e os dados levantados serao empregados para a construçao de um glossário onomasiológico da fauna brasileira