Data

 

264 datasets found! (Query time: 1 ms)

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251. Onodera, J; Takahashi, K (2012): (Appendix 1) Major silicoflagellate skeletons from IODP Exp302

     Size:

     5211 data points

     https://doi.org/10.1594/PANGAEA.787516 - Score: 6.746
252. Spofforth, DJA; Pälike, H; Green, DRH (2008): Element concentration of sediments of Hole 302-M0004A

     Size:

     108 data points

     https://doi.org/10.1594/PANGAEA.659169 - Score: 6.746
253. O'Regan, M; Moran, K; Baxter, CDP et al. (2012): (Table 2) Average elastic properties of sedimentary subunits where consolidation samples were taken from different Holes of IODP Expedition 302

     Size:

     24 data points

     https://doi.org/10.1594/PANGAEA.788556 - Score: 6.746
254. O'Regan, M; Sakamoto, T; King, JW (2008): (Table 1) Core recovery summary and vertical core offsets (affine) for the meters composite depth and revised meters composite depth scales of Hole 302-M0004A

     Size:

     252 data points

     https://doi.org/10.1594/PANGAEA.707032 - Score: 6.746
255. Boucsein, B; Stein, R (2008): Macerals in sediments

     Abstract:

     The study of particulate organic matter (OM) in Arctic Ocean sediments from the Late Cretaceous to the Eocene (IODP Expedition 302) has revealed detailed information about the aquatic/marine OM fluxes, biological sources, preservation and export of terrestrial material. Here, we present detailed data from maceral analysis, vitrinite reflectance measurements and organic geochemistry. During the Campanian/Paleocene, fluxes of land-derived OM are indicated by reworked and oxidized macerals (vitrinite, inertinite) and terrigenous liptinite (cutinite, sporinite). In the Early Eocene, drastic environmental changes are indicated by peaks in aquatic OM (up to 40-45%, lamalginite, telalginite, liptodetrinite, dinoflagellate cysts) and amorphous OM (up to 50% bituminite). These events of increased aquatic OM flux, similar to conditions favoring black shale deposition, correlate with the global d13C events "Paleocene/Eocene Thermal Maximum" (PETM) and "Elmo-event". […]

     Size:

     2 datasets

     https://doi.org/10.1594/PANGAEA.690523 - Score: 5.324
256. Frank, M; Backman, J; Jakobsson, M et al. (2008): (Table 1) The 10Be and 9Be isotope record of IODP EXP202 composite Site

     Abstract:

     The upper 200 m of the sediments recovered during IODP Leg 302, the Arctic Coring Expedition (ACEX), to the Lomonosov Ridge in the central Arctic Ocean consist almost exclusively of detrital material. The scarcity of biostratigraphic markers severely complicates the establishment of a reliable chronostratigraphic framework for these sediments, which contain the first continuous record of the Neogene environmental and climatic evolution of the Arctic region. Here we present profiles of cosmogenic 10Be together with the seawater-derived fraction of stable 9Be obtained from the ACEX cores. The down-core decrease of 10Be/9Be provides an average sedimentation rate of 14.5 ± 1 m/Ma for the uppermost 151 m of the ACEX record and allows the establishment of a chronostratigraphy for the past 12.3 Ma. The age corrected 10Be concentrations and 10Be/9Be ratios suggest the existence of an essentially continuous sea ice cover over the past 12.3 Ma.

     Size:

     204 data points

     https://doi.org/10.1594/PANGAEA.734478 - Score: 4.738
257. Haley, BA; Frank, M; Spielhagen, RF et al. (2008): Radiogenic isotope record of Arctic Ocean circulation and weathering inputs of the past 15 million years

     Abstract:

     Lead (Pb), neodymium (Nd), and strontium (Sr) isotopic analyses were carried out on sediment leachates (reflecting the isotope composition of past seawater) and digests of the bulk residues (reflecting detrital continental inputs) of Integrated Ocean Drilling Program (IODP) Leg 302 and core PS2185 from the Lomonosov Ridge (Arctic Ocean). Our records are interpreted to reflect changes in continental erosion and oceanic circulation, driven predominantly by tectonic forcing on million-year timescales in the older (pre-2 Ma) part of the record and by climatic forcing of weathering and erosion of the Eurasian continental margin on thousand-year timescales in the younger (post-2 Ma) part. These data, covering the past ~15 Ma, show that continental inputs to the central Arctic Ocean have been more closely linked to glacial and hydrological processes occurring on the Eurasian margin than on continental North America and Greenland. […]

     Size:

     3 datasets

     https://doi.org/10.1594/PANGAEA.734430 - Score: 4.159
258. Haley, BA; Frank, M; Spielhagen, RF et al. (2008): Neodymium and Strontium chemistry of Arctic Ocean sediments

     Abstract:

     The early oceanographic history of the Arctic Ocean is important in regulating, and responding to, climatic changes. However, constraints on its oceanographic history preceding the Quaternary (the past 1.8 Myr) have become available only recently, because of the difficulties associated with obtaining continuous sediment records in such a hostile setting. Here, we use the neodymium isotope compositions of two sediment cores recovered near the North Pole to reconstruct over the past ~5 Myr the sources contributing to Arctic Intermediate Water, a water mass found today at depths of 200 to 1,500 m. We interpret high neodymium ratios for the period between 15 and 2 Myr ago, and for the glacial periods thereafter, as indicative of weathering input from the Siberian Putoranan basalts into the Arctic Ocean. Arctic Intermediate Water was then derived from brine formation in the Eurasian shelf regions, with only a limited contribution of intermediate water from the North Atlantic. […]

     Size:

     3 datasets

     https://doi.org/10.1594/PANGAEA.769604 - Score: 3.89
259. Kraal, P; Slomp, CP; Forster, A et al. (2009): Geochemistry and P and Fe fractionation in anoxic sediments

     Abstract:

     We investigated the phosphorus (P) and iron (Fe) fractionation in four cores with anoxic sediments, deposited during the mid-Cretaceous oceanic anoxic event 2 (~94 Ma) and the Paleocene-Eocene thermal maximum (?55 Ma), that were exposed to oxygen after core recovery. Surprisingly, P associated with iron oxyhydroxides (Fe-bound P) was a major P phase in these laminated sediments deposited under euxinic conditions. A significant fraction of total Fe was present as (poorly) crystalline ferric Fe. This fraction increased with increasing storage time of the investigated cores. In carbonate-poor samples, Fe-bound P accounted for up to 99% of total P and its abundance correlated with pyrite contents. In samples with higher CaCO3 contents (>5 wt% in the investigated samples), P was mostly present in authigenic Ca-P minerals, irrespective of pyrite contents. […]

     Size:

     1068 data points

     https://doi.org/10.1594/PANGAEA.783338 - Score: 3.781
260. Chen, T-Y; Frank, M; Haley, BA et al. (2012): (Table 1) Nd-Hf isotopes from leachates and detrital materials of the Arctic sediments

     Abstract:

     The warm and saline North Atlantic inflow to the Arctic Ocean is a major component of high northern latitude circulation and the main mechanism of deep water renewal in the Arctic Ocean. Knowledge of its past variability is critical for understanding the high latitude feedback mechanisms of the climate system. Here we present the first combined seawater Hf and Nd isotope compositions of past Arctic Intermediate Water extracted from the authigenic Fe?Mn oxyhydroxide fraction of two sediment cores recovered near the North Pole, to reconstruct changes in contributions from glacial brines of the Eurasian shelf and past inflow of Atlantic waters. The Hf and Nd isotopic compositions obtained from leachates of the authigenic fraction show closely coupled and environmentally controlled variations over the past 14 million years. […]

     Size:

     522 data points

     https://doi.org/10.1594/PANGAEA.871708 - Score: 3.781

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