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Papers by Christophe Lécuyer
Comptes Rendus de l Académie des Sciences - Series IIB - Mechanics-Physics-Chemistry-Astronomy
Earth and Planetary Science Letters
Functional Ecology, 2015
ABSTRACT Identifying feeding strategies at lower bounds of habitat productivity is fundamental to... more ABSTRACT Identifying feeding strategies at lower bounds of habitat productivity is fundamental to understand the relationship between energy availability and trophic specialization. Low productivity is expected to severely constrain trophic specialization because organisms may no longer be able to fulfil their energy requirements by feeding on a reduced set of resources. However, species living in low-productivity habitats often exhibit particular biological traits such as low metabolic rates and high food-finding abilities, which may release constraints on trophic specialization.In the present study, we used carbon
Physicochemical and Biological Properties, 2013
Earth and Planetary Science Letters, 2013
Journal of Human Evolution, 65: 185-198
Comptes Rendus de l'Académie des Sciences-Series IIA-Earth and Planetary Science, Jun 30, 1997
The Blanco trough (Juan de Fuca ridge) exposes a continuous section of the upper part of the ocea... more The Blanco trough (Juan de Fuca ridge) exposes a continuous section of the upper part of the oceanic crust (basalts and sheeted dykes) hydrothermally altered in a transform fault context. Coupled microthermometric measurements on fluid inclusions and stable oxygen isotope compositions of secondary phases from the diabase unit were performed to investigate the evolution of hydrothermal fluids. The existence of a dense fracture network directly linked to the geotectonic transform fault environment has maintained a still hot ...
Oecologia, Mar 1, 2006
The ¹⁵N/¹⁴N signature of animal proteins is now commonly used to understand their physiology and ... more The ¹⁵N/¹⁴N signature of animal proteins is now commonly used to understand their physiology and quantify the flows of nutrient in trophic webs. These studies assume that animals are predictably ¹⁵N-enriched relative to their food, but the isotopic mechanism which accounts for this enrichment remains unknown. We developed a box model of the nitrogen isotope cycle in mammals in order to predict the ¹⁵N/¹⁴N ratios of body reservoirs as a function of time, N intake and body mass. Results of modeling show that a ...
Bulletin de la Societe Geologique de France, 2011
Upper Carboniferous heating and melting of the middle orogenic crust associated with the emplacem... more Upper Carboniferous heating and melting of the middle orogenic crust associated with the emplacement of syntectonic granitoids are documented in the Upper Gneissic Unit of the Livradois area (central part of the French Massif Central). Crustal melting post-dates peak metamorphism conditions (800-625 C, 10-8 kb) dated at 360±4 Ma (U-Th-Pb on monazite). The PT evolution of the metamorphic series indicates that Barrovian metamorphism was followed by a decompression (from 10±1 kbar to 6±1 kbar) associated ...
Freshwater Biology, Mar 1, 2011
Summary 1. The functional feeding group approach has been widely used to describe the community s... more Summary 1. The functional feeding group approach has been widely used to describe the community structure of benthic invertebrates in relation to organic matter resources. Based on this functional framework, positive interactions between feeding groups (especially shredders and collector-gatherers) were postulated in the River Continuum Concept. However, relationships with organic matter have been poorly documented for invertebrates living in the hyporheic zone.
Geochimica et Cosmochimica Acta, Aug 15, 2011
Deuterium and oxygen isotope fractionations between liquid and vapor water were experimentally-de... more Deuterium and oxygen isotope fractionations between liquid and vapor water were experimentally-determined during evaporation of a NaCl solution (35gL− 1) as a function of water temperature and wind velocity. In the case of a null wind velocity, slopes of δD–δ18O trajectories of residual waters hyperbolically decrease with increasing water temperatures in the range 23–47° C. For wind velocities ranging from 0.8 to 2.2 ms− 1, slopes of the δD–δ18O trajectories linearly increase with increasing wind velocity at a given water ...
Applied Geochemistry, Nov 12, 2011
A semi-automatic, on-line method was developed to determine the δ13C and δ18O values of coexistin... more A semi-automatic, on-line method was developed to determine the δ13C and δ18O values of coexisting calcite and dolomite. An isotopic mass balance is used to calculate the compositions of dolomite after having measured that of calcite and of the “bulk” sample. The limit of validity of this method is established by performing isotopic measurements of artificial mixtures made of precisely weighted and isotopically-characterised dolomite and calcite. The accuracy and repeatability of the calculation of dolomite δ13C and δ18O are ...
Geological Magazine, 2011
Carbon-and oxygen-isotope ratios are commonly used to correlate shallow-and deep-marine successio... more Carbon-and oxygen-isotope ratios are commonly used to correlate shallow-and deep-marine successions. Carbon-and oxygen-isotope analyses were performed on bulk-carbonate samples from two Kimmeridgian sections of the Swiss Jura platform in order to correlate them with biostratigraphically well-dated coeval sections in the adjacent basin. On the platform, a general decrease in δ 13 C and δ 18 O values from the base to the top of the studied interval is measured, whereas time-equivalent pelagic–hemipelagic carbonates ...
Geological Society, London, Special Publications, 2006
New material from the Santa Marta Formation (late Coniacian-? early Maastrichtian) of James Ross ... more New material from the Santa Marta Formation (late Coniacian-? early Maastrichtian) of James Ross Island contributes significantly to the current knowledge of Late Cretaceous Antarctic fish diversity. The taxon list for the Santa Marta Formation is extended, and new records of neoselachians and teleosts are reported. The stratigraphic ranges of some previously known taxa are enlarged, and the palaeobiogeography and palaeoecology of Late Cretaceous Antarctic fishes are discussed. Top predators that occupied the higher ...
Geochimica et Cosmochimica Acta, Jul 31, 1998
δ18O values of both carbonate (18.7–25.1‰) and phosphate (15.1–16.7‰) components of the francolit... more δ18O values of both carbonate (18.7–25.1‰) and phosphate (15.1–16.7‰) components of the francolite from the fossil brachiopod shells are interpreted as the result of a partial resetting of pristine isotopic compositions. The similarity of hat-shape REE patterns of some lower Ordovician linguloids with those of extant littoral specimens suggests the preservation of a 500 Myr-old record of REE marine chemistry. In agreement with the known paleogeography, the phosphatic brachiopods have been deposited in a coastal ...
Comptes Rendus de l Académie des Sciences - Series IIB - Mechanics-Physics-Chemistry-Astronomy
Earth and Planetary Science Letters
Functional Ecology, 2015
ABSTRACT Identifying feeding strategies at lower bounds of habitat productivity is fundamental to... more ABSTRACT Identifying feeding strategies at lower bounds of habitat productivity is fundamental to understand the relationship between energy availability and trophic specialization. Low productivity is expected to severely constrain trophic specialization because organisms may no longer be able to fulfil their energy requirements by feeding on a reduced set of resources. However, species living in low-productivity habitats often exhibit particular biological traits such as low metabolic rates and high food-finding abilities, which may release constraints on trophic specialization.In the present study, we used carbon
Physicochemical and Biological Properties, 2013
Earth and Planetary Science Letters, 2013
Journal of Human Evolution, 65: 185-198
Comptes Rendus de l'Académie des Sciences-Series IIA-Earth and Planetary Science, Jun 30, 1997
The Blanco trough (Juan de Fuca ridge) exposes a continuous section of the upper part of the ocea... more The Blanco trough (Juan de Fuca ridge) exposes a continuous section of the upper part of the oceanic crust (basalts and sheeted dykes) hydrothermally altered in a transform fault context. Coupled microthermometric measurements on fluid inclusions and stable oxygen isotope compositions of secondary phases from the diabase unit were performed to investigate the evolution of hydrothermal fluids. The existence of a dense fracture network directly linked to the geotectonic transform fault environment has maintained a still hot ...
Oecologia, Mar 1, 2006
The ¹⁵N/¹⁴N signature of animal proteins is now commonly used to understand their physiology and ... more The ¹⁵N/¹⁴N signature of animal proteins is now commonly used to understand their physiology and quantify the flows of nutrient in trophic webs. These studies assume that animals are predictably ¹⁵N-enriched relative to their food, but the isotopic mechanism which accounts for this enrichment remains unknown. We developed a box model of the nitrogen isotope cycle in mammals in order to predict the ¹⁵N/¹⁴N ratios of body reservoirs as a function of time, N intake and body mass. Results of modeling show that a ...
Bulletin de la Societe Geologique de France, 2011
Upper Carboniferous heating and melting of the middle orogenic crust associated with the emplacem... more Upper Carboniferous heating and melting of the middle orogenic crust associated with the emplacement of syntectonic granitoids are documented in the Upper Gneissic Unit of the Livradois area (central part of the French Massif Central). Crustal melting post-dates peak metamorphism conditions (800-625 C, 10-8 kb) dated at 360±4 Ma (U-Th-Pb on monazite). The PT evolution of the metamorphic series indicates that Barrovian metamorphism was followed by a decompression (from 10±1 kbar to 6±1 kbar) associated ...
Freshwater Biology, Mar 1, 2011
Summary 1. The functional feeding group approach has been widely used to describe the community s... more Summary 1. The functional feeding group approach has been widely used to describe the community structure of benthic invertebrates in relation to organic matter resources. Based on this functional framework, positive interactions between feeding groups (especially shredders and collector-gatherers) were postulated in the River Continuum Concept. However, relationships with organic matter have been poorly documented for invertebrates living in the hyporheic zone.
Geochimica et Cosmochimica Acta, Aug 15, 2011
Deuterium and oxygen isotope fractionations between liquid and vapor water were experimentally-de... more Deuterium and oxygen isotope fractionations between liquid and vapor water were experimentally-determined during evaporation of a NaCl solution (35gL− 1) as a function of water temperature and wind velocity. In the case of a null wind velocity, slopes of δD–δ18O trajectories of residual waters hyperbolically decrease with increasing water temperatures in the range 23–47° C. For wind velocities ranging from 0.8 to 2.2 ms− 1, slopes of the δD–δ18O trajectories linearly increase with increasing wind velocity at a given water ...
Applied Geochemistry, Nov 12, 2011
A semi-automatic, on-line method was developed to determine the δ13C and δ18O values of coexistin... more A semi-automatic, on-line method was developed to determine the δ13C and δ18O values of coexisting calcite and dolomite. An isotopic mass balance is used to calculate the compositions of dolomite after having measured that of calcite and of the “bulk” sample. The limit of validity of this method is established by performing isotopic measurements of artificial mixtures made of precisely weighted and isotopically-characterised dolomite and calcite. The accuracy and repeatability of the calculation of dolomite δ13C and δ18O are ...
Geological Magazine, 2011
Carbon-and oxygen-isotope ratios are commonly used to correlate shallow-and deep-marine successio... more Carbon-and oxygen-isotope ratios are commonly used to correlate shallow-and deep-marine successions. Carbon-and oxygen-isotope analyses were performed on bulk-carbonate samples from two Kimmeridgian sections of the Swiss Jura platform in order to correlate them with biostratigraphically well-dated coeval sections in the adjacent basin. On the platform, a general decrease in δ 13 C and δ 18 O values from the base to the top of the studied interval is measured, whereas time-equivalent pelagic–hemipelagic carbonates ...
Geological Society, London, Special Publications, 2006
New material from the Santa Marta Formation (late Coniacian-? early Maastrichtian) of James Ross ... more New material from the Santa Marta Formation (late Coniacian-? early Maastrichtian) of James Ross Island contributes significantly to the current knowledge of Late Cretaceous Antarctic fish diversity. The taxon list for the Santa Marta Formation is extended, and new records of neoselachians and teleosts are reported. The stratigraphic ranges of some previously known taxa are enlarged, and the palaeobiogeography and palaeoecology of Late Cretaceous Antarctic fishes are discussed. Top predators that occupied the higher ...
Geochimica et Cosmochimica Acta, Jul 31, 1998
δ18O values of both carbonate (18.7–25.1‰) and phosphate (15.1–16.7‰) components of the francolit... more δ18O values of both carbonate (18.7–25.1‰) and phosphate (15.1–16.7‰) components of the francolite from the fossil brachiopod shells are interpreted as the result of a partial resetting of pristine isotopic compositions. The similarity of hat-shape REE patterns of some lower Ordovician linguloids with those of extant littoral specimens suggests the preservation of a 500 Myr-old record of REE marine chemistry. In agreement with the known paleogeography, the phosphatic brachiopods have been deposited in a coastal ...