Data

 

96 datasets found! (Query time: 3 ms)

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11. Waddell, LM; Moore, TC (2008): Salinity of the Eocene Arctic Ocean from oxygen isotope analysis of fish bone carbonate

    Abstract:

    Stable isotope analysis was performed on the structural carbonate of fish bone apatite from early and early middle Eocene samples (~55 to ~45 Ma) recently recovered from the Lomonosov Ridge by Integrated Ocean Drilling Program Expedition 302 (the Arctic Coring Expedition). The d18O values of the Eocene samples ranged from -6.84 per mil to -2.96 per mil Vienna Peedee belemnite, with a mean value of -4.89 per mil, compared to 2.77 per mil for a Miocene sample in the overlying section. An average salinity of 21 to 25 per mil was calculated for the Eocene Arctic, compared to 35 per mil for the Miocene, with lower salinities during the Paleocene Eocene thermal maximum, the Azolla event at ~48.7 Ma, and a third previously unidentified event at ~47.6 Ma. At the Azolla event, where the organic carbon content of the sediment reaches a maximum, a positive d13C excursion was observed, indicating unusually high productivity in the surface waters.

    Size:

    3 datasets

    https://doi.org/10.1594/PANGAEA.733934 - Score: 9.342
12. Weller, P; Stein, R (2010): (Table 1) CPI17-23, hopanoic acid, and n-C35 + lycopane/n-C31 ratios as well as 17beta(H), 21beta(H) homohopane, long-chain alkanes, and alkenones concentrations in IODP Exp302

    Abstract:

    During Integrated Ocean Drilling Program Expedition 302 (Arctic Coring Expedition (ACEX)) a more than 200 m thick sequence of Paleogene organic carbon (OC)-rich (black shale type) sediments was drilled. Here we present new biomarker data determined in ACEX sediment samples to decipher processes controlling OC accumulation and their paleoenvironmental significance during periods of Paleogene global warmth and proposed increased freshwater discharge in the early Cenozoic. Specific source-related biomarkers including n-alkanes, fatty acids, isoprenoids, carotenoids, hopanes/hopenes, hopanoic acids, aromatic terpenoids, and long-chain alkenones show a high variability of components, derived from marine and terrestrial origin. The distribution of hopanoic acid isomers is dominated by compounds with the biological 17beta(H), 21beta(H) configuration indicating a low level of maturity. […]

    Size:

    394 data points

    https://doi.org/10.1594/PANGAEA.733333 - Score: 8.794
13. Sangiorgi, F; Brumsack, H-J; Willard, DA et al. (2010): (Table 1) Element enrichment in dark versus light layers of the ''Zebra'' interval of IODP Hole 302-M0002A

    Size:

    57 data points

    https://doi.org/10.1594/PANGAEA.733255 - Score: 8.794
14. Eynaud, F (2007): Late Pleistocene planktonic foraminifera of Hole 302-M0004C (Addendum 1)

    Size:

    4208 data points

    https://doi.org/10.1594/PANGAEA.672076 - Score: 8.794
15. Eynaud, F; Cronin, TM; Smith, SA et al. (2009): (Table 1) Late Pleistocene planktonic foraminifera of Hole 302-M0004C

    Abstract:

    Planktonic foraminifera populations were studied throughout the top 25 meters of the IODP ACEX 302 Hole 4C from the central Arctic Ocean at a resolution varying from 5cm (at the top of the record) to 10cm. Planktonic foraminifera occur in high absolute abundances only in the uppermost fifty centimetres and are dominated by the taxa Neogloboquadrina pachyderma. Except for a few intermittent layers below this level,most samples are barren of calcareous microfossils.Within the topmost sediments, Neogloboquadrina pachyderma specimens present large morphological variability in the shape and number of chambers in the finalwhorl, chamber sphericity, size, and coiling direction. Five morphotypeswere identified among the sinistral (sin.) population (Nps-1 to Nps-5), including a small form (Nps-5) that is similar to a non-encrusted normal form also previously identified in the modern Arctic Ocean watermasses. […]

    Size:

    943 data points

    https://doi.org/10.1594/PANGAEA.672078 - Score: 8.691
16. Onodera, J; Takahashi, K; Jordan, RW (2010): (Table 2) Similarity Indexes (Pearson's correlation coefficient) of the silicoflagellate assemblages of IODP Exp302

    Abstract:

    The silicoflagellate and ebridian assemblages in early middle Eocene Arctic cores obtained by IODP Expedition 302 (ACEX) were studied in order to decipher the paleoceanography of the upper water column. The assemblages in Lithologic Unit 2 (49.7-45.1 Ma), one of the biosiliceous intervals, were usually endemic as compared to the assemblages that occurred outside of the Arctic Ocean. The presence of these endemic assemblages is probably due to a unique environmental setting, controlled by the degree of mixing between the low-salinity Arctic waters and relatively high salinity waters supplied from outside the Arctic Ocean, such as the Atlantic and possibly the Western Siberian Sea. Using the basin-to-basin fractionation model, the early middle Eocene Arctic Ocean corresponds to an estuarine circulation type, which includes the modern-day Black Sea. […]

    Size:

    20 data points

    https://doi.org/10.1594/PANGAEA.733882 - Score: 8.691
17. St. John, KEK (2010): (Table 1) Summary of general lithology in IODP Exp302 cores

    Abstract:

    The Cenozoic ice-rafted debris (IRD) history of the central Arctic is reconstructed utilizing the terrigenous coarse sand fraction in IODP 302 cores from 0 to 273 meters composite depth. This Holocene - middle Eocene quantitative record of terrigenous sand accumulation on the Lomonosov Ridge, along with qualitative information on grain texture and composition, confirms the interpretation that ice initiation (sea ice and glacial ice) occurred ~46 Ma in the Arctic, and provides a long-term pattern of Arctic ice expansion and decay since the middle Eocene. IRD mass accumulation rates range from 0 to 0.13 g/cm2/ka in the middle Eocene and from 0 to 0.36 g/cm2/ka in the Neogene. IRD mass accumulation rate (MAR) maxima in the Miocene and Pliocene cooccur with either glacial initiation or intensification in the sub-Arctic. […]

    Size:

    41 data points

    https://doi.org/10.1594/PANGAEA.734547 - Score: 8.691
18. Pagani, M; Pedentchouk, N; Huber, M et al. (2006): Stable carbon isotope ratios of alkane of IODP Hole 302-M0004A

    Abstract:

    The Palaeocene/Eocene thermal maximum represents a period of rapid, extreme global warming approx ~55 million years ago, superimposed on an already warm world (Zachos et al., 2003, doi:10.1126/science.1090110; Bowen et al., 2004, doi:10.1038/nature03115; Thomas et al., 2002, doi:10.1130/0091-7613(2002)030<1067:WTFFTF>2.0.CO;2). This warming is associated with a severe shoaling of the ocean calcite compensation depth **4 and a >2.5 per mil negative carbon isotope excursion in marine and soil carbonates (Zachos et al., 2003, doi:10.1126/science.1090110; Bowen et al., 2004, doi:10.1038/nature03115; Thomas et al., 2002, doi:10.1130/0091-7613(2002)030<1067:WTFFTF>2.0.CO;2; Zachos et al., doi:10.1126/science.1109004). Together these observations indicate a massive release of 13C-depleted carbon (Zachos et al., doi:10.1126/science.1109004) and greenhouse-gas-induced warming. […]

    Size:

    417 data points

    https://doi.org/10.1594/PANGAEA.733130 - Score: 8.691
19. 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: 8.687
20. 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: 8.687

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