The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Frédéric Boulvain - One of the best experts on this subject based on the ideXlab platform.
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Insights into a million-year-scale Rhenohercynian carbonate platform evolution through a multi-disciplinary approach: example of a Givetian carbonate record from Belgium
Geological Magazine, 2016Co-Authors: Damien Pas, A. C. Da Silva, Xavier Devleeschouwer, David De Vleeschouwer, Pierre Cornet, Corentin Labaye, Frédéric BoulvainAbstract:In this paper we formulate answers to three important questions related to Givetian carbonate records and their use for reconstructing million-year-scale past palaeoenvironmental changes. First, we provide detailed illustrations of the fascinating diversity that shaped a significant shallow reefal platform during early to late Givetian time in the Rhenohercynian Ocean; secondly we improve the sedimentological model of the extensive Givetian carbonate platform in the Dinant Basin; and thirdly we evaluate the application of magnetic susceptibility as a tool for long-term trend correlations and palaeoenvironmental reconstructions. These goals are reached by making a sedimentological, geophysical and geochemical study of the La Thure section. Through the early–late Givetian interval we discerned 18 microfacies ranging from a homoclinal ramp to a discontinuously rimmed shelf and then a drowning shelf. The comparison of these sedimentological results with those published for the south of the Dinant Syncline allowed us to provide an up to date model of the vertical and lateral environmental development of one of the largest Givetian carbonate platforms in Europe. This comparison also increased the knowledge on the distribution of facies belts in the Dinant Basin and allowed us to highlight the Taghanic Event. Palaeoredox proxies reveal a substantial change in the oxygenation level, from oxygen-depleted to more oxic conditions, between middle and late Givetian time. We demonstrated the relationship between variation in magnetic susceptibility values and proxies for siliciclastic input (such as Si, Al). The La Thure section is considered a key section for the understanding of internal shelf settings bordering Laurussia9s southeastern margin.
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The astronomical calibration of the Givetian (Middle Devonian) timescale (Dinant Synclinorium, Belgium)
Geological Society London Special Publications, 2014Co-Authors: David De Vleeschouwer, Damien Pas, Corentin Labaye, Frédéric Boulvain, Anne-christine Da Silva, Philippe ClaeysAbstract:Recent advances in radiometric dating result in significant improvements in the geo- logical timescale and provide better insight into the timing of various processes and evolutions within the Earth's system. However, no radiometric ages are contained within the Givetian. Con- sequently, the absolute ages of the Givetian Stage boundaries, as well as the stage's duration, remain poorly constrained. As an alternative, the analysis of sedimentary cycles allows for the esti- mation of the duration of this stage. We examined the high-resolution magnetic susceptibility signals of four Givetian outcrops in the Givet area for a possible astronomical imprint, to fully understand the rates of evolutionary and environmental change. All four sections are firmly corre- lated and wavelet analyses of the magnetic susceptibility signals reveal the imprint of astronomical eccentricity forcing. The highly stable 405 kyr cycles constrain the duration of the Givetian Stage at 4.35+ 0.45 Myr, which is in good agreement with the International Chronostratigraphic Chart (5.0 Myr). The studied sections also exhibit an imprint of obliquity, suggesting a climatic telecon- nection between low and high latitudes. The corresponding microfacies curves demonstrate similar astronomical imprint, and thereby indicate that the observed 10 5 year-scale cyclicity is the result of climatic and environmental change.
Jindřich Hladil - One of the best experts on this subject based on the ideXlab platform.
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Carbon and oxygen isotope record across Pridoli to Givetian stage boundaries in the Barrandian basin (Czech Republic)
Palaeogeography Palaeoclimatology Palaeoecology, 1997Co-Authors: Jana Hladikova, Jindřich HladilAbstract:Abstract Carbon and oxygen isotope composition and the chemistry of limestones, clayey limestones and shales were studied across stage boundaries from Pridoli to Givetian in the Barrandian basin. No substantial isotopic shifts were found at the Pragian–Emsian and Emsian–Eifelian boundaries. A gradual shift in δ13C values from −2.6 to +3.6‰ was observed in Pridoli and Lochkovian limestones. This shift is inferred to have been related to a combination of higher productivity, increased deposition of organic matter and shallowing of the basin. The global Kacak–otomari event just below the Eifelian–Givetian boundary is marked by an abrupt change in carbon isotopic values from about 1 to 3‰ in pelagic carbonates. No δ13C shift was found in shallow-water carbonates at the Eifelian–Givetian boundary. High δ18O values up to −1.3‰ in Pragian, Emsian and early Eifelian limestones indicate that the Barrandian basin was relatively isolated from the world ocean during those intervals. Lower δ18O values up to −7.5‰ in late Eifelian limestones may indicate the end of isolation.
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Carbon and oxygen isotope record across Pridoli to Givetian stage boundaries in the Barrandian basin (Czech Republic)
Palaeogeography Palaeoclimatology Palaeoecology, 1997Co-Authors: Jana Hladikova, Jindřich HladilAbstract:Abstract Carbon and oxygen isotope composition and the chemistry of limestones, clayey limestones and shales were studied across stage boundaries from Pridoli to Givetian in the Barrandian basin. No substantial isotopic shifts were found at the Pragian–Emsian and Emsian–Eifelian boundaries. A gradual shift in δ13C values from −2.6 to +3.6‰ was observed in Pridoli and Lochkovian limestones. This shift is inferred to have been related to a combination of higher productivity, increased deposition of organic matter and shallowing of the basin. The global Kacak–otomari event just below the Eifelian–Givetian boundary is marked by an abrupt change in carbon isotopic values from about 1 to 3‰ in pelagic carbonates. No δ13C shift was found in shallow-water carbonates at the Eifelian–Givetian boundary. High δ18O values up to −1.3‰ in Pragian, Emsian and early Eifelian limestones indicate that the Barrandian basin was relatively isolated from the world ocean during those intervals. Lower δ18O values up to −7.5‰ in late Eifelian limestones may indicate the end of isolation.
Damien Pas - One of the best experts on this subject based on the ideXlab platform.
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Insights into a million-year-scale Rhenohercynian carbonate platform evolution through a multi-disciplinary approach: example of a Givetian carbonate record from Belgium
Geological Magazine, 2016Co-Authors: Damien Pas, A. C. Da Silva, Xavier Devleeschouwer, David De Vleeschouwer, Pierre Cornet, Corentin Labaye, Frédéric BoulvainAbstract:In this paper we formulate answers to three important questions related to Givetian carbonate records and their use for reconstructing million-year-scale past palaeoenvironmental changes. First, we provide detailed illustrations of the fascinating diversity that shaped a significant shallow reefal platform during early to late Givetian time in the Rhenohercynian Ocean; secondly we improve the sedimentological model of the extensive Givetian carbonate platform in the Dinant Basin; and thirdly we evaluate the application of magnetic susceptibility as a tool for long-term trend correlations and palaeoenvironmental reconstructions. These goals are reached by making a sedimentological, geophysical and geochemical study of the La Thure section. Through the early–late Givetian interval we discerned 18 microfacies ranging from a homoclinal ramp to a discontinuously rimmed shelf and then a drowning shelf. The comparison of these sedimentological results with those published for the south of the Dinant Syncline allowed us to provide an up to date model of the vertical and lateral environmental development of one of the largest Givetian carbonate platforms in Europe. This comparison also increased the knowledge on the distribution of facies belts in the Dinant Basin and allowed us to highlight the Taghanic Event. Palaeoredox proxies reveal a substantial change in the oxygenation level, from oxygen-depleted to more oxic conditions, between middle and late Givetian time. We demonstrated the relationship between variation in magnetic susceptibility values and proxies for siliciclastic input (such as Si, Al). The La Thure section is considered a key section for the understanding of internal shelf settings bordering Laurussia9s southeastern margin.
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The astronomical calibration of the Givetian (Middle Devonian) timescale (Dinant Synclinorium, Belgium)
Geological Society London Special Publications, 2014Co-Authors: David De Vleeschouwer, Damien Pas, Corentin Labaye, Frédéric Boulvain, Anne-christine Da Silva, Philippe ClaeysAbstract:Recent advances in radiometric dating result in significant improvements in the geo- logical timescale and provide better insight into the timing of various processes and evolutions within the Earth's system. However, no radiometric ages are contained within the Givetian. Con- sequently, the absolute ages of the Givetian Stage boundaries, as well as the stage's duration, remain poorly constrained. As an alternative, the analysis of sedimentary cycles allows for the esti- mation of the duration of this stage. We examined the high-resolution magnetic susceptibility signals of four Givetian outcrops in the Givet area for a possible astronomical imprint, to fully understand the rates of evolutionary and environmental change. All four sections are firmly corre- lated and wavelet analyses of the magnetic susceptibility signals reveal the imprint of astronomical eccentricity forcing. The highly stable 405 kyr cycles constrain the duration of the Givetian Stage at 4.35+ 0.45 Myr, which is in good agreement with the International Chronostratigraphic Chart (5.0 Myr). The studied sections also exhibit an imprint of obliquity, suggesting a climatic telecon- nection between low and high latitudes. The corresponding microfacies curves demonstrate similar astronomical imprint, and thereby indicate that the observed 10 5 year-scale cyclicity is the result of climatic and environmental change.
David De Vleeschouwer - One of the best experts on this subject based on the ideXlab platform.
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Insights into a million-year-scale Rhenohercynian carbonate platform evolution through a multi-disciplinary approach: example of a Givetian carbonate record from Belgium
Geological Magazine, 2016Co-Authors: Damien Pas, A. C. Da Silva, Xavier Devleeschouwer, David De Vleeschouwer, Pierre Cornet, Corentin Labaye, Frédéric BoulvainAbstract:In this paper we formulate answers to three important questions related to Givetian carbonate records and their use for reconstructing million-year-scale past palaeoenvironmental changes. First, we provide detailed illustrations of the fascinating diversity that shaped a significant shallow reefal platform during early to late Givetian time in the Rhenohercynian Ocean; secondly we improve the sedimentological model of the extensive Givetian carbonate platform in the Dinant Basin; and thirdly we evaluate the application of magnetic susceptibility as a tool for long-term trend correlations and palaeoenvironmental reconstructions. These goals are reached by making a sedimentological, geophysical and geochemical study of the La Thure section. Through the early–late Givetian interval we discerned 18 microfacies ranging from a homoclinal ramp to a discontinuously rimmed shelf and then a drowning shelf. The comparison of these sedimentological results with those published for the south of the Dinant Syncline allowed us to provide an up to date model of the vertical and lateral environmental development of one of the largest Givetian carbonate platforms in Europe. This comparison also increased the knowledge on the distribution of facies belts in the Dinant Basin and allowed us to highlight the Taghanic Event. Palaeoredox proxies reveal a substantial change in the oxygenation level, from oxygen-depleted to more oxic conditions, between middle and late Givetian time. We demonstrated the relationship between variation in magnetic susceptibility values and proxies for siliciclastic input (such as Si, Al). The La Thure section is considered a key section for the understanding of internal shelf settings bordering Laurussia9s southeastern margin.
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The astronomical calibration of the Givetian (Middle Devonian) timescale (Dinant Synclinorium, Belgium)
Geological Society London Special Publications, 2014Co-Authors: David De Vleeschouwer, Damien Pas, Corentin Labaye, Frédéric Boulvain, Anne-christine Da Silva, Philippe ClaeysAbstract:Recent advances in radiometric dating result in significant improvements in the geo- logical timescale and provide better insight into the timing of various processes and evolutions within the Earth's system. However, no radiometric ages are contained within the Givetian. Con- sequently, the absolute ages of the Givetian Stage boundaries, as well as the stage's duration, remain poorly constrained. As an alternative, the analysis of sedimentary cycles allows for the esti- mation of the duration of this stage. We examined the high-resolution magnetic susceptibility signals of four Givetian outcrops in the Givet area for a possible astronomical imprint, to fully understand the rates of evolutionary and environmental change. All four sections are firmly corre- lated and wavelet analyses of the magnetic susceptibility signals reveal the imprint of astronomical eccentricity forcing. The highly stable 405 kyr cycles constrain the duration of the Givetian Stage at 4.35+ 0.45 Myr, which is in good agreement with the International Chronostratigraphic Chart (5.0 Myr). The studied sections also exhibit an imprint of obliquity, suggesting a climatic telecon- nection between low and high latitudes. The corresponding microfacies curves demonstrate similar astronomical imprint, and thereby indicate that the observed 10 5 year-scale cyclicity is the result of climatic and environmental change.
Corentin Labaye - One of the best experts on this subject based on the ideXlab platform.
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Insights into a million-year-scale Rhenohercynian carbonate platform evolution through a multi-disciplinary approach: example of a Givetian carbonate record from Belgium
Geological Magazine, 2016Co-Authors: Damien Pas, A. C. Da Silva, Xavier Devleeschouwer, David De Vleeschouwer, Pierre Cornet, Corentin Labaye, Frédéric BoulvainAbstract:In this paper we formulate answers to three important questions related to Givetian carbonate records and their use for reconstructing million-year-scale past palaeoenvironmental changes. First, we provide detailed illustrations of the fascinating diversity that shaped a significant shallow reefal platform during early to late Givetian time in the Rhenohercynian Ocean; secondly we improve the sedimentological model of the extensive Givetian carbonate platform in the Dinant Basin; and thirdly we evaluate the application of magnetic susceptibility as a tool for long-term trend correlations and palaeoenvironmental reconstructions. These goals are reached by making a sedimentological, geophysical and geochemical study of the La Thure section. Through the early–late Givetian interval we discerned 18 microfacies ranging from a homoclinal ramp to a discontinuously rimmed shelf and then a drowning shelf. The comparison of these sedimentological results with those published for the south of the Dinant Syncline allowed us to provide an up to date model of the vertical and lateral environmental development of one of the largest Givetian carbonate platforms in Europe. This comparison also increased the knowledge on the distribution of facies belts in the Dinant Basin and allowed us to highlight the Taghanic Event. Palaeoredox proxies reveal a substantial change in the oxygenation level, from oxygen-depleted to more oxic conditions, between middle and late Givetian time. We demonstrated the relationship between variation in magnetic susceptibility values and proxies for siliciclastic input (such as Si, Al). The La Thure section is considered a key section for the understanding of internal shelf settings bordering Laurussia9s southeastern margin.
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The astronomical calibration of the Givetian (Middle Devonian) timescale (Dinant Synclinorium, Belgium)
Geological Society London Special Publications, 2014Co-Authors: David De Vleeschouwer, Damien Pas, Corentin Labaye, Frédéric Boulvain, Anne-christine Da Silva, Philippe ClaeysAbstract:Recent advances in radiometric dating result in significant improvements in the geo- logical timescale and provide better insight into the timing of various processes and evolutions within the Earth's system. However, no radiometric ages are contained within the Givetian. Con- sequently, the absolute ages of the Givetian Stage boundaries, as well as the stage's duration, remain poorly constrained. As an alternative, the analysis of sedimentary cycles allows for the esti- mation of the duration of this stage. We examined the high-resolution magnetic susceptibility signals of four Givetian outcrops in the Givet area for a possible astronomical imprint, to fully understand the rates of evolutionary and environmental change. All four sections are firmly corre- lated and wavelet analyses of the magnetic susceptibility signals reveal the imprint of astronomical eccentricity forcing. The highly stable 405 kyr cycles constrain the duration of the Givetian Stage at 4.35+ 0.45 Myr, which is in good agreement with the International Chronostratigraphic Chart (5.0 Myr). The studied sections also exhibit an imprint of obliquity, suggesting a climatic telecon- nection between low and high latitudes. The corresponding microfacies curves demonstrate similar astronomical imprint, and thereby indicate that the observed 10 5 year-scale cyclicity is the result of climatic and environmental change.