Data

 

96 datasets found! (Query time: 18 ms)

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21. Ogawa, Y; Takahashi, K; Yamanaka, T et al. (2009): (Appendix A) Geochemistry for Units 1/6, 2, and the upper part of Unit 3 of IODP Holes 302-M0002A and 302-M0004A

    Abstract:

    Integrated Ocean Drilling Program (IODP) Expedition 302 Arctic Coring Expedition (ACEX) obtained the first relatively continuous long sediment cores from the Lomonosov Ridge in the central Arctic Ocean in 2004. Preceding microfossil studies indicated the dominance of low salinity surface waters in the early to middle Eocene Arctic basin. The main purpose of this study is to reconstruct paleoceanographic conditions including the extent of saline (seawater) mass presence. To attain this goal we performed geochemical analyses of total sulfur (%TS), total organic carbon (%TOC) and stable sulfur isotopic composition (d34S) on the early to middle Eocene section of the ACEX cores. The %TS were high in all the examined intervals and the sedimentary sulfur occurred mainly as framboidal pyrite, indicating that sufficient sulfate, indicative of seawater, was present in the deep layer of the paleo-Arctic basin and that the pyrite was formed in the sediments under sufficient iron input. […]

    Size:

    909 data points

    https://doi.org/10.1594/PANGAEA.785796 - Score: 8.873
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: 8.873
23. Weijers, JWH; Schouten, S; Sluijs, A et al. (2007): Reconstruction of continental mean air temperature across the PETM of IODP Hole 302-M0004A (Appendix A)

    Abstract:

    The Palaeocene-Eocene Thermal Maximum (PETM; ~55.5 Ma) is a geologically relatively brief episode of extreme warmth. Both deep and surface ocean temperatures increased by up to 5 °C in equatorial waters and up to 8 °C in mid and high latitude waters. From the continents, the annual mean air temperature response during the PETM is still largely unknown, mainly due to a lack of quantitative temperature proxies and sufficient suitable, continuous high resolution records. Recently, a new proxy for continental temperature reconstructions has been proposed, based on the distribution of membrane lipids of bacteria in present-day soils [Weijers et al., 2007, doi:10.1016/j.gca.2006.10.003] and shown to reconstruct annual mean air temperature. […]

    Size:

    219 data points

    https://doi.org/10.1594/PANGAEA.707279 - Score: 8.873
24. 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: 8.873
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: 8.794
26. 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: 8.146
27. Boucsein, B (2008): Macerals of Hole 302-M0004A

    Size:

    1008 data points

    https://doi.org/10.1594/PANGAEA.690519 - Score: 8.146
28. 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: 8.146
29. Vogt, C (2008): Relative mineral abundances from bulk fraction X-ray diffraction data of Hole 302-M0003A

    Size:

    936 data points

    https://doi.org/10.1594/PANGAEA.704657 - Score: 8.146
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: 8.146

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