The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Ian Probert - One of the best experts on this subject based on the ideXlab platform.

  • calibration of stable isotope composition of thoracosphaera heimii dinoflagellate calcite for reconstructing paleotemperatures in the intermediate Photic Zone
    Paleoceanography, 2014
    Co-Authors: Fabrice Minoletti, Michaël Hermoso, Yaël Candelier, Ian Probert
    Abstract:

    In this study we investigate the temperature dependence of oxygen isotope ratios preserved in calcite formed by the dinoflagellate Thoracosphaera heimii, focusing primarily on the development of a geological proxy. Geochemical analysis of the calcite shells produced by this species represents a valuable proxy for reconstructing environmental conditions in the intermediate Photic Zone. Calibration is based on isotopic analysis from culture experiments performed in very dilute batch conditions, as well as from near-monospecific T. heimii assemblages separated from core top sediments. Results are similar for both approaches and indicate that T. heimii shells have oxygen isotope compositions close to equilibrium values predicted for inorganic calcite precipitation. This calibration of the isotopic composition of dinoflagellate calcite indicates that monospecific assemblages of T. heimii can be used to unravel paleotemperatures in the intermediate Photic Zone by applying isotopic transfer functions for equilibrium calcite. In culture, however, a δ 18 O offset of A1‰ is observed at temperatures <17°C, which falls below the natural temperature range of this species. Culture analyses also reveal a relationship between temperature and carbon isotope composition of calcite. The mechanisms behind this relationship remain to be explored, but their identification may provide a better understanding of carbon isotope systematics from both biogeochemical and geological perspectives. Comparison of the oxygen isotope composition of T. heimii shells with that of shallower dwelling organisms, such as the coccolithophores, represents a valuable proxy for determining temperature gradients within the Photic Zone and may enable reconstruction of the evolution of the depth of the thermocline.

  • Calibration of stable isotope composition of Thoracosphaera heimii (dinoflagellate) calcite for reconstructing paleotemperatures in the intermediate Photic Zone
    Paleoceanography, 2014
    Co-Authors: Fabrice Minoletti, Michaël Hermoso, Yaël Candelier, Ian Probert
    Abstract:

    In this study we investigate the temperature dependence of oxygen isotope ratios preserved in calcite formed by the dinoflagellate Thoracosphaera heimii, focusing primarily on the development of a geological proxy. Geochemical analysis of the calcite shells produced by this species represents a valuable proxy for reconstructing environmental conditions in the intermediate Photic Zone. Calibration is based on isotopic analysis from culture experiments performed in very dilute batch conditions, as well as from near-monospecific T. heimii assemblages separated from core top sediments. Results are similar for both approaches and indicate that T. heimii shells have oxygen isotope compositions close to equilibrium values predicted for inorganic calcite precipitation. This calibration of the isotopic composition of dinoflagellate calcite indicates that monospecific assemblages of T. heimii can be used to unravel paleotemperatures in the intermediate Photic Zone by applying isotopic transfer functions for equilibrium calcite. In culture, however, a δ 18 O offset of À1‰ is observed at temperatures

Fabrice Minoletti - One of the best experts on this subject based on the ideXlab platform.

  • calibration of stable isotope composition of thoracosphaera heimii dinoflagellate calcite for reconstructing paleotemperatures in the intermediate Photic Zone
    Paleoceanography, 2014
    Co-Authors: Fabrice Minoletti, Michaël Hermoso, Yaël Candelier, Ian Probert
    Abstract:

    In this study we investigate the temperature dependence of oxygen isotope ratios preserved in calcite formed by the dinoflagellate Thoracosphaera heimii, focusing primarily on the development of a geological proxy. Geochemical analysis of the calcite shells produced by this species represents a valuable proxy for reconstructing environmental conditions in the intermediate Photic Zone. Calibration is based on isotopic analysis from culture experiments performed in very dilute batch conditions, as well as from near-monospecific T. heimii assemblages separated from core top sediments. Results are similar for both approaches and indicate that T. heimii shells have oxygen isotope compositions close to equilibrium values predicted for inorganic calcite precipitation. This calibration of the isotopic composition of dinoflagellate calcite indicates that monospecific assemblages of T. heimii can be used to unravel paleotemperatures in the intermediate Photic Zone by applying isotopic transfer functions for equilibrium calcite. In culture, however, a δ 18 O offset of A1‰ is observed at temperatures <17°C, which falls below the natural temperature range of this species. Culture analyses also reveal a relationship between temperature and carbon isotope composition of calcite. The mechanisms behind this relationship remain to be explored, but their identification may provide a better understanding of carbon isotope systematics from both biogeochemical and geological perspectives. Comparison of the oxygen isotope composition of T. heimii shells with that of shallower dwelling organisms, such as the coccolithophores, represents a valuable proxy for determining temperature gradients within the Photic Zone and may enable reconstruction of the evolution of the depth of the thermocline.

  • Calibration of stable isotope composition of Thoracosphaera heimii (dinoflagellate) calcite for reconstructing paleotemperatures in the intermediate Photic Zone
    Paleoceanography, 2014
    Co-Authors: Fabrice Minoletti, Michaël Hermoso, Yaël Candelier, Ian Probert
    Abstract:

    In this study we investigate the temperature dependence of oxygen isotope ratios preserved in calcite formed by the dinoflagellate Thoracosphaera heimii, focusing primarily on the development of a geological proxy. Geochemical analysis of the calcite shells produced by this species represents a valuable proxy for reconstructing environmental conditions in the intermediate Photic Zone. Calibration is based on isotopic analysis from culture experiments performed in very dilute batch conditions, as well as from near-monospecific T. heimii assemblages separated from core top sediments. Results are similar for both approaches and indicate that T. heimii shells have oxygen isotope compositions close to equilibrium values predicted for inorganic calcite precipitation. This calibration of the isotopic composition of dinoflagellate calcite indicates that monospecific assemblages of T. heimii can be used to unravel paleotemperatures in the intermediate Photic Zone by applying isotopic transfer functions for equilibrium calcite. In culture, however, a δ 18 O offset of À1‰ is observed at temperatures

Yaël Candelier - One of the best experts on this subject based on the ideXlab platform.

  • calibration of stable isotope composition of thoracosphaera heimii dinoflagellate calcite for reconstructing paleotemperatures in the intermediate Photic Zone
    Paleoceanography, 2014
    Co-Authors: Fabrice Minoletti, Michaël Hermoso, Yaël Candelier, Ian Probert
    Abstract:

    In this study we investigate the temperature dependence of oxygen isotope ratios preserved in calcite formed by the dinoflagellate Thoracosphaera heimii, focusing primarily on the development of a geological proxy. Geochemical analysis of the calcite shells produced by this species represents a valuable proxy for reconstructing environmental conditions in the intermediate Photic Zone. Calibration is based on isotopic analysis from culture experiments performed in very dilute batch conditions, as well as from near-monospecific T. heimii assemblages separated from core top sediments. Results are similar for both approaches and indicate that T. heimii shells have oxygen isotope compositions close to equilibrium values predicted for inorganic calcite precipitation. This calibration of the isotopic composition of dinoflagellate calcite indicates that monospecific assemblages of T. heimii can be used to unravel paleotemperatures in the intermediate Photic Zone by applying isotopic transfer functions for equilibrium calcite. In culture, however, a δ 18 O offset of A1‰ is observed at temperatures <17°C, which falls below the natural temperature range of this species. Culture analyses also reveal a relationship between temperature and carbon isotope composition of calcite. The mechanisms behind this relationship remain to be explored, but their identification may provide a better understanding of carbon isotope systematics from both biogeochemical and geological perspectives. Comparison of the oxygen isotope composition of T. heimii shells with that of shallower dwelling organisms, such as the coccolithophores, represents a valuable proxy for determining temperature gradients within the Photic Zone and may enable reconstruction of the evolution of the depth of the thermocline.

  • Calibration of stable isotope composition of Thoracosphaera heimii (dinoflagellate) calcite for reconstructing paleotemperatures in the intermediate Photic Zone
    Paleoceanography, 2014
    Co-Authors: Fabrice Minoletti, Michaël Hermoso, Yaël Candelier, Ian Probert
    Abstract:

    In this study we investigate the temperature dependence of oxygen isotope ratios preserved in calcite formed by the dinoflagellate Thoracosphaera heimii, focusing primarily on the development of a geological proxy. Geochemical analysis of the calcite shells produced by this species represents a valuable proxy for reconstructing environmental conditions in the intermediate Photic Zone. Calibration is based on isotopic analysis from culture experiments performed in very dilute batch conditions, as well as from near-monospecific T. heimii assemblages separated from core top sediments. Results are similar for both approaches and indicate that T. heimii shells have oxygen isotope compositions close to equilibrium values predicted for inorganic calcite precipitation. This calibration of the isotopic composition of dinoflagellate calcite indicates that monospecific assemblages of T. heimii can be used to unravel paleotemperatures in the intermediate Photic Zone by applying isotopic transfer functions for equilibrium calcite. In culture, however, a δ 18 O offset of À1‰ is observed at temperatures

Joan Rosell - One of the best experts on this subject based on the ideXlab platform.

  • a model for the palaeoenvironmental distribution of larger foraminifera based on late middle eocene deposits on the margin of the south pyrenean basin ne spain
    Palaeogeography Palaeoclimatology Palaeoecology, 2002
    Co-Authors: Josep Romero, Esmeralda Caus, Joan Rosell
    Abstract:

    Abstract On the margin of the South Pyrenean basin, the late Middle Eocene sediments represent a well preserved regressive system permitting determination of the distribution of larger foraminifera along the depth gradient. Eocene deposits are compared with distribution patterns of Recent larger foraminifera based on taxa occupying comparable positions along similar ecological gradients. Eocene taxa reveal by their test morphology a similar response to specific ecological conditions to that recorded for Recent foraminifera. Four assemblages characterise an open marine shelf; they range from the lower limit of the Photic Zone to the lower part of the upper Photic Zone. Two assemblages characterise the upper part of the upper Photic Zone, and indicate, respectively, two different substrates, firm or soft. Below the Photic Zone, no larger foraminifera exist and the foraminiferal assemblages are dominated by smaller benthic foraminifera.

  • A model for the palaeoenvironmental distribution of larger foraminifera based on late Middle Eocene deposits on the margin of the South Pyrenean basin (NE Spain)
    Palaeogeography Palaeoclimatology Palaeoecology, 2002
    Co-Authors: Josep M. Romero, Esmeralda Caus, Joan Rosell
    Abstract:

    Abstract On the margin of the South Pyrenean basin, the late Middle Eocene sediments represent a well preserved regressive system permitting determination of the distribution of larger foraminifera along the depth gradient. Eocene deposits are compared with distribution patterns of Recent larger foraminifera based on taxa occupying comparable positions along similar ecological gradients. Eocene taxa reveal by their test morphology a similar response to specific ecological conditions to that recorded for Recent foraminifera. Four assemblages characterise an open marine shelf; they range from the lower limit of the Photic Zone to the lower part of the upper Photic Zone. Two assemblages characterise the upper part of the upper Photic Zone, and indicate, respectively, two different substrates, firm or soft. Below the Photic Zone, no larger foraminifera exist and the foraminiferal assemblages are dominated by smaller benthic foraminifera.

Michaël Hermoso - One of the best experts on this subject based on the ideXlab platform.

  • calibration of stable isotope composition of thoracosphaera heimii dinoflagellate calcite for reconstructing paleotemperatures in the intermediate Photic Zone
    Paleoceanography, 2014
    Co-Authors: Fabrice Minoletti, Michaël Hermoso, Yaël Candelier, Ian Probert
    Abstract:

    In this study we investigate the temperature dependence of oxygen isotope ratios preserved in calcite formed by the dinoflagellate Thoracosphaera heimii, focusing primarily on the development of a geological proxy. Geochemical analysis of the calcite shells produced by this species represents a valuable proxy for reconstructing environmental conditions in the intermediate Photic Zone. Calibration is based on isotopic analysis from culture experiments performed in very dilute batch conditions, as well as from near-monospecific T. heimii assemblages separated from core top sediments. Results are similar for both approaches and indicate that T. heimii shells have oxygen isotope compositions close to equilibrium values predicted for inorganic calcite precipitation. This calibration of the isotopic composition of dinoflagellate calcite indicates that monospecific assemblages of T. heimii can be used to unravel paleotemperatures in the intermediate Photic Zone by applying isotopic transfer functions for equilibrium calcite. In culture, however, a δ 18 O offset of A1‰ is observed at temperatures <17°C, which falls below the natural temperature range of this species. Culture analyses also reveal a relationship between temperature and carbon isotope composition of calcite. The mechanisms behind this relationship remain to be explored, but their identification may provide a better understanding of carbon isotope systematics from both biogeochemical and geological perspectives. Comparison of the oxygen isotope composition of T. heimii shells with that of shallower dwelling organisms, such as the coccolithophores, represents a valuable proxy for determining temperature gradients within the Photic Zone and may enable reconstruction of the evolution of the depth of the thermocline.

  • Calibration of stable isotope composition of Thoracosphaera heimii (dinoflagellate) calcite for reconstructing paleotemperatures in the intermediate Photic Zone
    Paleoceanography, 2014
    Co-Authors: Fabrice Minoletti, Michaël Hermoso, Yaël Candelier, Ian Probert
    Abstract:

    In this study we investigate the temperature dependence of oxygen isotope ratios preserved in calcite formed by the dinoflagellate Thoracosphaera heimii, focusing primarily on the development of a geological proxy. Geochemical analysis of the calcite shells produced by this species represents a valuable proxy for reconstructing environmental conditions in the intermediate Photic Zone. Calibration is based on isotopic analysis from culture experiments performed in very dilute batch conditions, as well as from near-monospecific T. heimii assemblages separated from core top sediments. Results are similar for both approaches and indicate that T. heimii shells have oxygen isotope compositions close to equilibrium values predicted for inorganic calcite precipitation. This calibration of the isotopic composition of dinoflagellate calcite indicates that monospecific assemblages of T. heimii can be used to unravel paleotemperatures in the intermediate Photic Zone by applying isotopic transfer functions for equilibrium calcite. In culture, however, a δ 18 O offset of À1‰ is observed at temperatures