Total organic carbon content, methane isotopic composition and hydrocarbon characteristics of ODP Leg 180 sites

The organic geochemistry of Sites 1108 and 1109 of the Woodlark Basin, offshore Papua New Guinea, was studied to determine whether thermally mature hydrocarbons were present in the penetrated section and, if present, whether they are genetically related to the penetrated "coaly" interval. Both the organic carbon and pyrolysis data indicate that there is no significant hydrocarbon source-rock potential at Site 1108. The hydrocarbons encountered during drilling appear to be indigenous and not migrated products or contaminants. In contrast, the coaly interval at Site 1109 contains zones with significant hydrocarbon-generation potential. Several independent lines of evidence indicate that the coaly sequence encountered at Site 1109 is thermally immature. The Site 1108 methane stable-carbon isotope composition does not display a clear trend with depth as would be expected if it was solely reflecting a maturation profile. The measured isotopic composition of methane has most probably been altered by fractionation during sample handling and storage. This fractionation would result in isotopically heavier values than would be obtained on free gas. The organic geochemical data gathered indicate that Site 1108 can be safely revisited and that the organic-rich sediments encountered at Site 1109 were not the source of the gas encountered at Site 1108.

(Table 1) Mercury concentrations and carbon and nitrogen isotopic ratios in 14 marine species from West Greenland sampled between 2003-2004

Total mercury (THg), methylmercury (MeHg) and stable isotopes of nitrogen (d15N) and carbon (d13C) were measured in three invertebrate, five fish, three seabird and three marine mammal species of central West Greenland to investigate trophic transfer of mercury in this Arctic marine food web. The food web magnification factor (FWMF) estimated as the slope of the regression between the natural logarithm of THg or MeHg concentrations (mg/kg dw) and tissue d15N (per mil) was estimated to 0.183 (SE = 0.052) for THg and 0.339 (SE = 0.075) for MeHg. The FWMFs were not only comparable with those reported for other Arctic marine food webs but also with quite different food webs such as freshwater lakes in the sub-Arctic, East Africa and Papua New Guinea. This suggests similar mechanisms of mercury assimilation and isotopic (d15N) discrimination among a broad range of aquatic taxa and underlines the possibility of broad ecosystem comparisons using the combined contaminant and stable isotope approach.

Sediment biogeochemistry at CO2 vents off Papua-New Guinea (2013, 2014)

Measurement of biogeochemical parameters in coral reef sediments at carbon dioxide vents off Upa-Upasina (Normandy Island, Papua-New Guinea). The data includes in-situ micro/minisensor profiles, sediment characteristics, microbial and meiofauna abundances of vent sediments and reference sites without vent influence.

(Supplemet S1) Silicon oxide and Potassium + Sodium oxide from the PACManus hydrothermal area

This study presents a systematic analysis and interpretation of autonomous underwater vehicle-based microbathymetry combined with remotely operated vehicle (ROV) video recordings, rock analyses and temperaturemeasurements within the PACManus hydrothermal area located on Pual Ridge in the Bismarck Sea of eastern Manus Basin. The data obtained during research cruise Magellan-06 and So-216 provides a framework for understanding the relationship between the volcanism, tectonismand hydrothermal activity. PACManus is a submarine felsic vocanically-hosted hydrothermal area that hosts multiple vent fields locatedwithin several hundredmeters of one another but with different fluid chemistries, vent temperatures and morphologies. The total area of hydrothermal activity is estimated to be 20,279m**2. Themicrobathymetrymaps combinedwith the ROV video observations allow for precise high-resolution mapping estimates of the areal extents of hydrothermal activity.We find the distribution of hydrothermal fields in the PACManus area is primarily controlled by volcanic features that include lava domes, thick andmassive blocky lava flows, breccias and feeder dykes. Spatial variation in the permeability of local volcanic facies appears to control the distribution of venting within a field.We define a three-stage chronological sequence for the volcanic evolution of the PACManus based on lava flow morphology, sediment cover and lava SiO2 concentration. In Stage-1, sparsely to moderately porphyritic dacite lavas (68-69.8 wt.% SiO2) erupted to form domes or cryptodomes. In Stage-2, aphyric lava with slightly lower SiO2 concentrations (67.2-67.9 wt.% SiO2) formed jumbled and pillowed lava flows. In the most recent phase Stage-3, massive blocky lavaswith 69 to 72.5wt.% SiO2were erupted throughmultiple vents constructing a volcanic ridge identified as the PACManus neovolcanic zone. The transition between these stages may be gradual and related to progressive heating of a silicic magma following a recharge event of hot, mantle-derived melts.

The Global Plankton Database: an inventory and data from the Former Soviet Union expeditions

At present time, there is a lack of knowledge on the interannual climate-related variability of zooplankton communities of the tropical Atlantic, central Mediterranean Sea, Caspian Sea, and Aral Sea, due to the absence of appropriate databases. In the mid latitudes, the North Atlantic Oscillation (NAO) is the dominant mode of atmospheric fluctuations over eastern North America, the northern Atlantic Ocean and Europe. Therefore, one of the issues that need to be addressed through data synthesis is the evaluation of interannual patterns in species abundance and species diversity over these regions in regard to the NAO. The database has been used to investigate the ecological role of the NAO in interannual variations of mesozooplankton abundance and biomass along the zonal array of the NAO influence. Basic approach to the proposed research involved: (1) development of co-operation between experts and data holders in Ukraine, Russia, Kazakhstan, Azerbaijan, UK, and USA to rescue and compile the oceanographic data sets and release them on CD-ROM, (2) organization and compilation of a database based on FSU cruises to the above regions, (3) analysis of the basin-scale interannual variability of the zooplankton species abundance, biomass, and species diversity.

Carbon, boron and oxygen isotope ratios of sediments from the Moresby Seamount

We report results from boron, carbon and oxygen stable isotope analyses of faulted and veined rocks recovered by scientific ocean drilling during ODP Leg 180 in the western Woodlark Basin, off Papua New Guinea. In this area of active continental extension, crustal break-up and incipient seafloor spreading, a shallow-dipping, seismically active detachment fault accommodates strain, defining a zone of mylonites and cataclasites, vein formation and fluid infiltration. Syntectonic microstructures and vein-fill mineralogy suggest frictional heating during slip during extension and exhumation of Moresby Seamount. Low carbon and oxygen isotope ratios of calcite veins indicate precipitation from hydrothermal fluids (delta13C PDB down to -17?; delta18O PDB down to -22?) formed by both dehydration and decarbonation. Boron contents are low (<7 ppm), indicating high-grade metamorphic source rock for the fluids. Some of the delta11B signatures (17-35?; parent solutions to calcite vein fills) are low when compared to deep-seated waters in other tectonic environments, likely reflecting preferential loss of 11B during low-grade metamorphism at depth. Pervasive devolatilization and flux of CO2-rich fluids are evident from similar vein cement geochemistry in the detachment fault zone and splays further updip. Multiple rupture-and-healing history of the veins suggests that precipitation may be an important player in fluid pressure evolution and, hence, seismogenic fault movement.