Recursos de colección

PANGAEA - Publishing Network for Geoscientific & Environmental Data (830.700 recursos)

The information system PANGAEA is operated as an Open Access library aimed at archiving, publishing and distributing georeferenced data from earth system research. The system guarantees long-term availability of its content through a commitment of the operating institutions.

Datasets with geocode "AGE"

Mostrando recursos 1 - 20 de 56.514

  1. Authigenic uranium, mass accumulation rates, benthic d13C and SST reconstruction for ODP Site 177-1094

    Hayes, Christoper T; Martinez-Garcia, Alfredo; Hasenfratz, Albin; Jaccard, Samuel L; Hodell, David A; Sigman, Daniel M; Haug, Gerald H; Anderson, Robert F

  2. Authigenic uranium, mass accumulation rates, benthic d13C and SST during the last interglacial period of ODP Site 177-1094

    Hayes, Christoper T; Martinez-Garcia, Alfredo; Hasenfratz, Albin; Jaccard, Samuel L; Hodell, David A; Sigman, Daniel M; Haug, Gerald H; Anderson, Robert F
    Southern Ocean sediments reveal a spike in authigenic uranium 127,000 years ago, within the last interglacial, reflecting decreased oxygenation of deep water by Antarctic Bottom Water (AABW). Unlike ice age reductions in AABW, the interglacial stagnation event appears decoupled from open ocean conditions and may have resulted from coastal freshening due to mass loss from the Antarctic ice sheet. AABW reduction coincided with increased North Atlantic Deep Water (NADW) formation, and the subsequent reinvigoration in AABW coincided with reduced NADW formation. Thus, alternation of deep water formation between the Antarctic and the North Atlantic, believed to characterize ice ages, apparently...

  3. Planktic foraminiferal Mg/Ca and oxygen isotopes, plus estimated d18Oseawater and ice volume corrected d18Oseawater for the past 35000 years of sediment core GeoB10069-3

    Gibbons, Fern T; Oppo, Delia W; Mohtadi, Mahyar; Rosenthal, Yair; Cheng, Jun; Liu, Zhengyu; Linsley, Braddock K
    Evidence from geologic archives suggests that there were large changes in the tropical hydrologic cycle associated with the two prominent northern hemisphere deglacial cooling events, Heinrich Stadial 1 (HS1; ~19 to 15 kyr BP; kyr BP = 1000 yr before present) and the Younger Dryas (~12.9 to 11.7 kyr BP). These hydrologic shifts have been alternatively attributed to high and low latitude origin. Here, we present a new record of hydrologic variability based on planktic foraminifera-derived d18O of seawater (d18Osw) estimates from a sediment core from the tropical Eastern Indian Ocean, and using 12 additional d18Osw records, construct a single...

  4. Principal component analysis of sediment core GeoB10069-3

    Gibbons, Fern T; Oppo, Delia W; Mohtadi, Mahyar; Rosenthal, Yair; Cheng, Jun; Liu, Zhengyu; Linsley, Braddock K

  5. Mg/Ca measurement and oxygen isotope ratios of sediment core GeoB10069-3

    Gibbons, Fern T; Oppo, Delia W; Mohtadi, Mahyar; Rosenthal, Yair; Cheng, Jun; Liu, Zhengyu; Linsley, Braddock K

  6. Age determination of sediments and biomarkers of ODP Hole 169-1034C

    Smittenberg, Rienk H; Hopmans, Ellen C; Schouten, Stefan; Hayes, John M; Eglinton, Timothy I; Sinninghe Damsté, Jaap S
    The radiocarbon contents of various biomarkers extracted from the varve-counted sediments of Saanich Inlet, Canada, were determined to assess their applicability for dating purposes. Calibrated ages obtained from the marine planktonic archaeal biomarker crenarchaeol compared favorably with varve-count ages. The same conclusion could be drawn for a more general archaeal biomarker (GDGT-0), although this biomarker proved to be less reliable due to its less-specific origin. The results also lend support to earlier indications that marine crenarchaeota use dissolved inorganic carbon (DIC) as their carbon source. The average reservoir age offset DR of 430 years, determined using the crenarchaeol radiocarbon ages,...

  7. (Table 4a) Calibrated age ranges obtained with the atmospheric calibration curve, of sedimentary total organic carbon, terrestrial macrofossils, and isolated biomarkers originating from differently aged sediment layers, ODP Hole 169-1034C

    Smittenberg, Rienk H; Hopmans, Ellen C; Schouten, Stefan; Hayes, John M; Eglinton, Timothy I; Sinninghe Damsté, Jaap S

  8. (Table 5) Reservoir ages in 14C years BP and reservoir age offsets DR for ODP Hole 169-1034C samples

    Smittenberg, Rienk H; Hopmans, Ellen C; Schouten, Stefan; Hayes, John M; Eglinton, Timothy I; Sinninghe Damsté, Jaap S

  9. (Table 4b) Calibrated age ranges obtained with the marine calibration curve, of sedimentary total organic carbon, terrestrial macrofossils, and isolated biomarkers originating from differently aged sediment layers, ODP Hole 169-1034C

    Smittenberg, Rienk H; Hopmans, Ellen C; Schouten, Stefan; Hayes, John M; Eglinton, Timothy I; Sinninghe Damsté, Jaap S

  10. (Table 2) Amounts, stable and radiocarbon isotopic compositions of sedimentary total organic carbon, terrestrial macrofossils, and isolated biomarkers originating from differently aged sediment layers, ODP Hole 169-1034C

    Smittenberg, Rienk H; Hopmans, Ellen C; Schouten, Stefan; Hayes, John M; Eglinton, Timothy I; Sinninghe Damsté, Jaap S

  11. (Table 3) Initial radiocarbon contents and conventional radiocarbon ages of sedimentary total organic carbon, terrestrial macrofossils, and isolated biomarkers originating from differently aged sediment layers, ODP Hole 169-1034C

    Smittenberg, Rienk H; Hopmans, Ellen C; Schouten, Stefan; Hayes, John M; Eglinton, Timothy I; Sinninghe Damsté, Jaap S

  12. Calcite accumulation in the eastern equatorial Pacific

    Loubere, Paul; Mekik, Figen; Francois, Roger; Pichat, Sylvain
    The eastern equatorial Pacific (EEP) is an important center of biological productivity, generating significant organic carbon and calcite fluxes to the deep ocean. We reconstructed paleocalcite flux for the past 30,000 years in four cores collected beneath the equatorial upwelling and the South Equatorial Current (SEC) by measuring ex230Th-normalized calcite accumulation rates corrected for dissolution with a newly developed proxy for "fraction of calcite preserved". This method produced very similar results at the four sites and revealed that the export flux of calcite was 30-50% lower during the LGM compared to the Holocene. The internal consistency of these results supports...

  13. (Table 2) Calcite accumulation rates in the eastern equatorial Pacific

    Loubere, Paul; Mekik, Figen; Francois, Roger; Pichat, Sylvain

  14. (Table 3) Th230 excess content and calcite accumulation rates in the eastern equatorial Pacific

    Loubere, Paul; Mekik, Figen; Francois, Roger; Pichat, Sylvain

  15. (Table 1) Previously published, corrected postpublication and new measurements of Nitrogen abundance and stable isotope ratios in ODP Hole 117-724C

    Higginson, Matthew J; Altabet, Mark A

  16. Comparison of nitrogen isotopic values from different preparation methods

    Higginson, Matthew J; Altabet, Mark A
    We are writing to comment on the work of Tamburini et al. (2003, doi:10.1029/2000PA000616). During the course of subsequent discussions between the authors and ourselves, it has become clear that the published sedimentary nitrogen isotopic values for Ocean Drilling Program (ODP) Site 724 are in error. Our reanalysis of sediment samples from the same intervals has revealed a significant offset from the original d15N data, requiring a revised assessment of their initial interpretation. The purposes of this comment are to (1) address the origin of these errors; (2) outline a protocol for future validation of nitrogen isotopic analyses; and (3)...

  17. Nd and Pb isotope signatures of the clay-size fraction of sediment core MD99-2227

    Fagel, Nathalie; Hillaire-Marcel, Claude; Humblet, Marc; Brasseur, G; Weis, D; Stevenson, R
    Nd and Pb isotopes were measured on the fine fraction of one sediment core drilled off southern Greenland. This work aims to reconstruct the evolution of deep circulation patterns in the North Atlantic during the Holocene on the basis of sediment supply variations. For the last 12 kyr, three sources have contributed to the sediment mixture: the North American Shield, the Pan-African and Variscan crusts, and the Mid-Atlantic Ridge. Clay isotope signatures indicate two mixtures of sediment sources. The first mixture (12.2-6.5 ka) is composed of material derived from the North American shield and from a "young" crustal source. From...

  18. Vertical flux reconstruction for sediment cores off Chile

    Dezileau, Laurent; Ulloa, Osvaldo; Hebbeln, Dierk; Lamy, Frank; Reyss, Jean-Louis
    Biogenic opal and organic carbon vertical rain rates in sediment cores reveal a strong cyclicity in the productivity of the upwelling system off presently arid northern Chile during the last 100,000 years. Changes in productivity are found to be in phase with the precessional cycle (~20,000 years) and with inputs of iron from the continent. During austral summer insolation maxima, increased precipitation and river runoff in the region appear to have brought high inputs of iron, mainly from the Andes, to the coastal ocean enhancing primary productivity there. We interpret our results as providing evidence for iron control of past...

  19. (Table 1) Th, TOC and opal content in sediment cores GeoB3375-1 and GeoB7101-1

    Dezileau, Laurent; Ulloa, Osvaldo; Hebbeln, Dierk; Lamy, Frank; Reyss, Jean-Louis

  20. (Table 2) Nd and PB isotope record of the carbonate-free clay fraction of sediment core MD99-2227

    Fagel, Nathalie; Hillaire-Marcel, Claude; Humblet, Marc; Brasseur, G; Weis, D; Stevenson, R

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.