Data

 

96 datasets found! (Query time: 2 ms)

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21. Ogawa, Y; Takahashi, K; Yamanaka, T (2012): (Table 2) Geochemical analysis from IODP Exp302

    Abstract:

    Geochemical analyses of biogenic opal, total organic carbon (TOC), total sulfur (TS), and stable sulfur isotopic composition were conducted on the middle Eocene section of the ACEX cores obtained by IODP Expedition 302. The analyzed %TS contents were high in all the examined intervals, indicating sufficient sea water was present in the deep layer of the paleo Arctic basin in contrast with the low salinity surface waters determined by freshwater siliceous microfossils. From the high %TS in Lithological Unit 1/6, the extent of sea water supply from outside of the Arctic basin appeared to have increased after 45 Ma. The euxinic condition of the bottom water is suggested by the TOC-TS diagram. The anoxic environment was brought about by the estuarine type circulation pattern and salinity stratification. The light sulfur isotope composition (d34S) indicates the microbial sulfate reduction in an open system. […]

    Size:

    1738 data points

    https://doi.org/10.1594/PANGAEA.787402 - Score: 8.687
22. Eynaud, F (2011): Planktonic foraminifera and microfossil composition of IODP Hole 302-M0004C

    Abstract:

    Calcareous microfossils are widely used by paleoceanographers to investigate past sea-surface hydrology. Among these microfossils, planktonic foraminifera are probably the most extensively used tool (e.g. [1] for a review), as they are easy to extract from the sediment and can also be used for coupled geochemical (e.g; d18O, d13C, Mg/Ca) and paleo-ecological investigations. Planktonic foraminifera are marine protists, which build a calcareous shell made of several chambers which reflect in their chemistry the properties of the ambient water-masses. Planktonic foraminifera are known to thrive in various habitats, distributed not only along a latitudinal gradient, but also along different water-depth intervals within surface waters (0-1000 m). Regarding their biogeographical distribution, planktonic foraminifera assemblages therefore mirror different water-masses properties, such as temperature, salinity and nutrient content of the surface water in which they live. […]

    Size:

    3709 data points

    https://doi.org/10.1594/PANGAEA.788078 - Score: 8.687
23. Sluijs, A; Schouten, S; Pagani, M et al. (2006): (Table S1) Palynology of IODP Hole 302-M0004A

    Abstract:

    The Palaeocene/Eocene thermal maximum, 55 million years ago, was a brief period of widespread, extreme climatic warming (Zachos et al., 2003; Kennett and Stott, 1991, doi:10.1038/353225a0; Tripati and Elderfield, 2005, doi:10.1126/science.1109202), that was associated with massive atmospheric greenhouse gas input (Dickens et al., 1995, doi:10.1029/95PA02087). Although aspects of the resulting environmental changes are well documented at low latitudes, no data were available to quantify simultaneous changes in the Arctic region. Here we identify the Palaeocene/Eocene thermal maximum in a marine sedimentary sequence obtained during the Arctic Coring Expedition (Backman et al., 2006, doi:10.2204/iodp.proc.302.2006). We show that sea surface temperatures near the North Pole increased from 18 °C to over 23 °C during this event. Such warm values imply the absence of ice and thus exclude the influence of ice-albedo feedbacks on this Arctic warming. […]

    Size:

    1185 data points

    https://doi.org/10.1594/PANGAEA.769815 - Score: 8.687
24. Sluijs, A; Röhl, U; Schouten, S et al. (2008): (Table 1) Elemental mean values of the upper Paleocene and lower Eocene in IODP Hole 302-M0004A

    Abstract:

    We reconstruct the latest Paleocene and early Eocene (~57-50 Ma) environmental trends in the Arctic Ocean and focus on the Paleocene-Eocene thermal maximum (PETM) (~55 Ma), using strata recovered from the Lomonosov Ridge by the Integrated Ocean Drilling Program Expedition 302. The Lomonosov Ridge was still partially subaerial during the latest Paleocene and earliest Eocene and gradually subsided during the early Eocene. Organic dinoflagellate cyst (dinocyst) assemblages point to brackish and productive surface waters throughout the latest Paleocene and early Eocene. Dinocyst assemblages are cosmopolitan during this time interval, suggesting warm conditions, which is corroborated by TEX86'-reconstructed temperatures of 15°-18°C. Inorganic geochemistry generally reflects reducing conditions within the sediment and euxinic conditions during the upper lower Eocene. […]

    Size:

    125 data points

    https://doi.org/10.1594/PANGAEA.733796 - Score: 8.586
25. Cronin, TM; Smith, SA; Eynaud, F et al. (2008): Age determination and stable carbon isotope ratios of Neogloboquadrina pachyderma of IODP Hole 302-M0004C

    Abstract:

    The Integrated Ocean Drilling Program (IODP) Arctic Coring Expedition (ACEX) Hole 4C from the Lomonosov Ridge in the central Arctic Ocean recovered a continuous 18 m record of Quaternary foraminifera yielding evidence for seasonally ice-free interglacials during the Matuyama, progressive development of large glacials during the mid-Pleistocene transition (MPT) ~1.2-0.9 Ma, and the onset of high-amplitude 100-ka orbital cycles ~500 ka. Foraminiferal preservation in sediments from the Arctic is influenced by primary (sea ice, organic input, and other environmental conditions) and secondary factors (syndepositional, long-term pore water dissolution). Taking these into account, the ACEX 4C record shows distinct maxima in agglutinated foraminiferal abundance corresponding to several interglacials and deglacials between marine isotope stages (MIS) 13-37, and although less precise dating is available for older sediments, these trends appear to continue through the Matuyama. […]

    Size:

    30 data points

    https://doi.org/10.1594/PANGAEA.706303 - Score: 8.493
26. Onodera, J; Takahashi, K (2012): (Table 2) Mean abundance of ebridian taxa in each ebridian assemblage group from IODP Exp302

    Size:

    52 data points

    https://doi.org/10.1594/PANGAEA.787524 - Score: 7.914
27. Haley, BA; Frank, M; Spielhagen, RF et al. (2008): Neodymium and Strontium chemistry of IODP Exp302-Composite Site

    Size:

    138 data points

    https://doi.org/10.1594/PANGAEA.769603 - Score: 7.914
28. März, C; Vogt, C; Schnetger, B et al. (2011): X-ray diffraction analysis of sediments of IODP Hole 302-M0002A

    Size:

    13254 data points

    https://doi.org/10.1594/PANGAEA.747735 - Score: 7.914
29. Krylov, AA; Andreeva, IA; Vogt, C et al. (2008): (Table 2) Relative abundance of autigenic minerals of Hole 302-M0002A

    Size:

    85 data points

    https://doi.org/10.1594/PANGAEA.707422 - Score: 7.914
30. O'Regan, M; Sakamoto, T; King, JW (2008): (Table 4) Correlation tie points of Exp302 (ACEX) composite depth scale and cores 96/12-1PC and PS2185-6

    Size:

    60 data points

    https://doi.org/10.1594/PANGAEA.707039 - Score: 7.914

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