1,070 Works

Biogenic sedimentation at ODP Site 138-847

David W Murray, John W Farrell & V S McKenna
Site 847, located on the equator beneath the region of divergent-driven upwelling in the eastern tropical Pacific Ocean, provides a continuous record of biogenic sedimentation spanning the past 3 m.y. Sediments at the site are primarily composed of carbonate and opal microfossils, with secondary amounts of detrital material that was transported to the site by means of winds. The cyclic changes in the relative abundance of carbonate and opal during the past 1 m.y. exhibit...

3D models created from ROV videos and their corresponding subtransect dimensions

Laura Fillinger & Tobias Funke
Underwater video transects have become a common tool for quantitative analysis of the seafloor. However a major difficulty remains in the accurate determination of the area surveyed as underwater navigation can be unreliable and image scaling does not always compensate for distortions due to perspective and topography. Depending on the camera set-up and available instruments, different methods of surface measurement are applied, which make it difficult to compare data obtained by different vehicles. 3-D modelling...

Mineralogy and stable isotopic composition of carbonates and sulfide minerals from ODP Leg 164 sites

Catherine Pierre, Jean Marie Rouchy & Annie Gaudichet
During Ocean Drilling Program Leg 164, gas hydrates were recovered in the Blake Ridge where the top of the gas hydrate zone lies at about 200 meters below seafloor (mbsf) and the bottom-simulating reflector (BSR) is located at about 450 mbsf. There is no sedimentological discontinuity crossing the BSR. The BSR is disrupted by the salt piercement of the Cape Fear Diapir. The authigenic carbonates (dolomite and siderite) are always present in small amounts (a...

Downhole variations in grain sizes at DSDP/ODP Hole 504B

Susumu Umino
The maximum grain sizes of plagioclase and magnetite in the groundmass of the sheeted dike complex drilled at Hole 504B have been measured. Downhole variations through a 440-m-long section show a crude zig-zag pattern consisting of a gradual decrease or increase followed by an abrupt jump. The gradual decrease or increase in grain size extends over many lithologic units, and hence, does not reflect variations in grain size within a single dike. Such a zig-zag...

Sedimentological, geochemical, micropaleontological and rock magnetic proxies of sediment core GeoB6211-2

Sebastian Razik, Cristiano Mazur Chiessi, Oscar E Romero & Tilo von Dobeneck
Surface currents and sediment distribution of the SE South American upper continental margin are under influence of the South American Monsoon System (SAMS) and the Southern Westerly Wind Belt (SWWB). Both climatic systems determine the meridional position of the Subtropical Shelf Front (STSF) and probably also of the Brazil-Malvinas Confluence (BMC). We reconstruct the changing impact of the SAMS and the SWWB on sediment composition at the upper Rio Grande Cone off southern Brazil during...

Body mass, flipper length, oxidative balance indices and telomere length of king penguin chicks (A. patagonicus) on Possession Island

Sylvie Geiger, Maryline le Vaillant, Thomas Lebard, Sophie Reichert, Antoine Stier, Yvon Le Maho & Francois Criscuolo
One of the reasons for animals not to grow as fast as they potentially could is that fast growth has been shown to be associated with reduced lifespan. However, we are still lacking a clear description of the reality of growth-dependent modulation of ageing mechanisms in wild animals. Using the particular growth trajectory of small king penguin chicks naturally exhibiting higher-than-normal growth rate to compensate for the winter break, we tested whether oxidative stress and...

Silicoflagellates and ebridians from ODP Leg 138 holes

Kevin McCartney, J H Churchill & Linda Woestendiek
The biostratigraphic distribution and abundance of middle Miocene to Pleistocene silicoflagellates is documented from Ocean Drilling Program (ODP) Leg 138 Holes 844B, 847B, 848B, 849B, 850B, 85 IB, 852B, and 854B from the eastern Equatorial Pacific Ocean. The silicoflagellates were generally abundant and well preserved and frequently exhibited an unusually large range of variation. The upper Miocene of near-equatorial sites includes an assemblage of Bachmannocena diodon nodosa, which includes a bridge across the width of...

Distribution of recurrent planktonic and benthic foraminifera at DSDP Hole 75-530A

C L McNulty
Hole 530A of Leg 75 is located in the southeastern corner of the Angola Basin of the South Atlantic (19° 11.26' S; 9°23.15 'E), on the abyssal seafloor (4629 m depth), close to the Walvis Ridge and near its junction with the continental margin. The hole penetrated 503 m of Cretaceous (Maestrichtian to Albian) and bottomed in basalt at 1121 m. No other hole of Leg 75 was drilled below the Neogene. Most of the...

Magnetic properties of plutonic rocks at DSDP Leg 82 holes

Guy M Smith & Subir K Banerjee
Ten samples of gabbro and peridotite, with varying degrees of serpentinization, were studied by magnetic techniques and reflected light microscopy. Evidence from these methods suggests that the natural remanent magnetization is primarily of chemical origin. It is generally weak for the gabbros and much stronger for the peridotites. This difference is offset by the fact that the peridotites have generally lower magnetic stability and Koenigsberger ratios. There is a considerable variation in both magnetic parameters...

Plankton abundance and feeding characteristics of Thysanoessa raschii from Godthabsfjord, Greenland

Mette Dalgaard Agersted, Torkel Gissel Nielsen, Peter Munk, Bent Vismann & Kristine Engel Arendt
Despite being a key zooplankton group, knowledge on krill biology from the Arctic is inadequate. The present study examine the functional biology and evaluate the trophic role of krill in the Godthabsfjord (64°N, 51°W) SW Greenland, through a combination of fieldwork and laboratory experiments. Krill biomass was highest in the middle fjord and inner fjord, whereas no krill was found offshore. The dominating species Thysanoessa raschii revealed a type III functional response when fed with...

Geochemical composition of surface sediments in the Trondheimsfjord, central Norway

Johan C Faust, Jochen Knies, Trond Slagstad, Christoph Vogt, Gesa Milzer & Jacques Giraudeau
High sedimentation rates in fjords provide excellent possibilities for high resolution sedimentary and geochemical records over the Holocene. As a baseline for an improved interpretation of geochemical data from fjord sediment cores, this study aims to investigate the inorganic/organic geochemistry of surface sediments and to identify geochemical proxies for terrestrial input and river discharge in the Trondheimsfjord, central Norway. Sixty evenly distributed surface sediment samples were analysed for their elemental composition, total organic carbon (Corg),...

Absorption characteristics, major elements and chl a content of samples from Pond 19 at Zackenberg, NE Greenland

Matteo Cazzanelli, Laura Forsström, Milla Rautio, Anders Michelsen & Kirsten Seestern Christoffersen
1. Shallow arctic lakes and ponds have simple and short food webs, but large uncertainties remain about benthic-pelagic links in these systems. We tested whether organic matter of benthic origin supports zooplankton biomass in a pond in NE Greenland, using stable isotope analysis of carbon and nitrogen in the pond itself and in a 13C-enrichment enclosure experiment. In the latter, we manipulated the carbon isotope signature of benthic algae to enhance its isotopic discrimination from...

Measured water discharges, suspended supply and morphometric parameters of cross-sections in the Lena River Delta during summer period 2002-2012

Irina V Fedorova, Dimitry Yu Bolshiyanov, Antonina Chetverova, Aleksandr Makarov & Mikhail Tretiyakov
The datasets present hydrographic measurements on discharge and suspended supply in the Lena River Delta in the summer periods from 2002 to 2012. Water discharge was calculated according to profile depth and water current velocity measurements, sediment supply was received after water sampling, filtration and turbidity carrying out. Measurements on the standard hydrometrical cross-sections of Roshydromet (Russian Federal Service for Hydrometorology and Environmental Monitoring) are coded with "H". These are across the Lena Main Channel...

First results from the Arctic Mid-Ocean Ridge Expedition with POLARSTERN and HEALY

Jörn Thiede, Jörg Barrais, Sergej Drachev, Steffen Gauger, Christian Haas, Thomas Hartmann, Jörn Hatzky, Gert König-Langlo, Jan L Lieser, Frank Niessen, Hans Werner Schenke, Vladimir P Shevchenko, Jonathan E Snow & Robert F Spielhagen
Helicopter borne sea ice thickness measurements, documentation of sediment cores, meteorological observations, physical oceanography, dredge samples and other data obtained during the Arctic Mid-Ocean Ridge Expedition with POLARSTERN and HEALY.

Mercury species concentrations near Casey station, Antarctica and along the SR3 CASO-GEOTRACES transect

Daniel Cossa, Lars-Eric Heimbürger, Delphine Lannuzel, Stephen R Rintoul, Edward C V Butler, Andrew R Bowie, Bernard Averty, Roslyn J Watson & Tomas Remenyi
We present here the first mercury speciation study in the water column of the Southern Ocean, using a high-resolution south-to-north section (27 stations from 65.50°S to 44.00°S) with up to 15 depths (0-4440 m) between Antarctica and Tasmania (Australia) along the 140°E meridian. In addition, in order to explore the role of sea ice in Hg cycling, a study of mercury speciation in the 'snow-sea ice-seawater' continuum was conducted at a coastal site, near the...

Sedimentology on profiles from Lake Prespa, Greece

Bernd Wagner, Anne Aufgebauer, Hendrik Vogel, Giovanni Zanchetta, Roberto Sulpizio & Magret Damaschke
Hydro-acoustic surveys and coring campaigns at Lake Prespa were carried out between 2007 and 2009. This paper presents hydro-acoustic profiles and provide lithological and chronostratigraphical information from three up to 15.75 m long sediment sequences from the Macedonian side of the lake. The sediment sequences comprise glacial and interglacial sediments likely deposited from the end of Marine Isotope Stage (MIS) 5 to present day. The information implies a distinct change of sedimentation patterns at the...

Magnetic properties and chemical composition at DSDP Hole 77-538A

Toshio Furuta & Hajimu Kinoshita
Magnetic properties of doleritic and some metamorphic basement rocks underlying Catoche Knoll are studied. Doleritic rocks show a high saturation magnetic moment (2-5 emu/g) compared to metamorphic rocks (0.1-1 emu/g). Magnetic minerals of rocks from this hole show a high stability when heated in vacuo up to 600°C at a fixed rate of heating. Curie temperatures are distributed close to 550°C. These properties differ markedly from those of common submarine basalts observed before. X-ray microprobe...

Calcium carbonate, total and organic carbon and accumulation rate characteristics at DSDP Leg 78A Holes

Audrey Wright
Bulk sediment accumulation rates and carbonate and carbonate-free accumulation rates corrected for tectonic tilting have been calculated for Leg 78A sediments. These rates are uniformly low, ranging from 0.1 to 6.8 g/(cm**2 x 10**3 yr.), reflecting the pelagic-hemipelagic nature of all the sediments drilled in the northern Lesser Antilles forearc. Rates calculated for Sites 541 and 542 [0.6-6.8 g/(cm**2 x 10**3 yr.)], located on the lower slope of the accretionary prism, are significantly greater than...

Major-oxides and trace-elements at DSDP Hole 78-543A

James H Natland, John Tarney, Nicholas G Marsh, William G Melson & Timothy O'Hearn
Four chemically distinct basalts were cored in 44 m of basement penetration at Deep Sea Drilling Project Site 543, in Upper Cretaceous crust just seaward of the deformation front of the Barbados Ridge and north of the Tiburon Rise. All four types are moderately fractionated abyssal tholeiites. The four types have different magnetic inclinations, all of reversed polarity, suggesting eruption at different times which recorded secular variation of the earth's magnetic field. Extensive replacement of...

Foraminiferal species and dissolution index at DSDP Hole 78-541

Christoph Hemleben & Anabelle Auras
The calcite compensation depth (CCD) fluctuates as a result of changes in the water-mass system, thereby producing a distinct dissolution pattern. Differential dissolution changes the composition of the foraminiferal assemblages, reflecting the depositional environment in respect to the fluctuating CCD. The dissolution pattern for the comparatively shallow Site 541 on the Barbados Ridge indicates a depositional environment mostly above the CCD, but below the foraminiferal lysocline during the late Miocene to early Pleistocene. In contrast,...

Radiocarbon dates of Mytilus shells and peat and wood samples collected on Drayton Island

Anne-Marie Lemieux, Najat Bhiry & Pierre M Desrosiers
A multidisciplinary study was undertaken at the Qijurittuq Site (IbGk-3) on Drayton Island in Low-Arctic Quebec (Canada) to document the relationships between climatic, environmental, and cultural changes and the choice of Thule/Inuit dwelling style in the eastern Arctic. Several marine terraces were 14C-dated with shells in order to reconstruct the area's uplift (glacioisostatic rebound) curve. Plant macrofossil analysis of peat was conducted to reconstruct past vegetation and, indirectly, past climate. Archaeological surveys and excavations characterized...

The physical properties of basalt at DSDP Hole 45-395A

Roy D Hyndman, Nikolas I Christensen & Malcolm J Drury
A detailed study has been made of the physical properties of core samples from Deep Sea Drilling Project Hole 395A. The properties include: density, porosity, compressional and shear wave velocity, thermal conductivity, thermal diffusivity, and electrical resistivity. Of particular importance are the relations among the parameters. Most of the variations in the basalt properties follow the porosity, with smaller inferred dependence on pore structure, original mineralogy differences, and alteration. The sample measurements give very similar...

Basic measurements and other of radiation from the Baseline Surface Radiation Network (BSRN) Station Ny-Ålesund in the years 1992 to 2011, reference list of 228 datasets

Marion Maturilli, Andreas Herber & Gert König-Langlo
Any user who accepts the BSRN data release guidelines (http://bsrn.awi.de/data/conditions-of-data-release) may ask Amelie Driemel (mailto:Amelie.Driemel@awi.de) to obtain an account to download these datasets.

40Ar/39Ar analysis for incremental heating experiments at DSDP Holes 77-537 and 77-538A

R D Dallmeyer
Drilling penetrated pre-Mesozoic crystalline basement beneath abbreviated sedimentary sequences overlying fault blocks in the southeastern Gulf of Mexico. At Hole 538A, located on Catoche Knoll, a foliated, regional metamorphic association of variably mylonitic felsic gneisses and interlayered amphibolite is intruded by post-tectonic diabase dikes. Hornblende from the amphibolite displays internally discordant 40Ar/39Ar age spectra, suggesting initial post-metamorphic cooling at about 500 Ma followed by a mild thermal disturbance at about 200 Ma. Biotite from the...

Maceral distribution, stratigraphic position and vitrinite reflectance at DSDP Hole 81-555

Jane Lund & Walter Riegel
Twenty-four sediment samples from late Paleocene to early Eocene were studied for maceral content, vitrinite reflectance, and spectral fluorescence in order to determine some parameters of the origin and diagenetic history of their organic fraction. The sediments had been obtained at Site 555 of DSDP Leg 81 in the northeastern North Atlantic. The bulk of the microscopically visible fraction is made up of humic materials; inertinites follow as a distant second; and liptinites are exceedingly...

Registration Year

  • 2013

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  • Collection