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| Counts, John; Jorry, Stephan; Vazquez Riveiros, Natalia; Jouet, Gwenael; Giraudeau, Jacques; Cheron, Sandrine; Boissier, Audrey; Miramontes, Elda. |
| A 27 m core collected on the seafloor near Juan de Nova island at 1909 m depth in the SW Indian Ocean preserves a high‐resolution record of carbonate sediment export to the deep sea over the past 1 Myr. Core chronology was established using calcareous nannofossil biostratigraphy and benthic foraminiferal δ18O. Throughout the core, preserved highstand intervals (MIS 1, 5, 7, 9, 11, 13, 15, 23 and 25) are marked by an increase in the aragonite content within the sediment. Aragonite is likely sourced from the nearby Juan de Nova carbonate platform ~10 km to the south, and is interpreted to result from flooding of the platform top. Platform inundation allows carbonate muds to be winnowed from their original shallow‐water environment of deposition, suspended in... |
| Tipo: Text |
Palavras-chave: Aragonite; Atoll; MIS 11; Mozambique Channel; Sea-level change. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00474/58553/61108.pdf |
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| Poulain, C.; Gillikin, D. P.; Thebault, Julien; Munaron, Jean-marie; Bohn, M; Robert, Rene; Paulet, Yves-marie; Lorrain, Anne. |
| The influence of salinity and water chemistry on Mg/Ca, Sr/Ca and Ba/Ca ratios in the aragonitic shells of the Manila clam were investigated. Clams were reared at constant temperature (20 °C) under different controlled conditions of salinity, commonly encountered in their natural habitat. Clams were held in three tanks with a constant salinity of 35 for the first 35 days and then two tanks were changed to lower salinities (20 and 28) for the next 29 days. Individual shell Mg/Ca, Sr/Ca and Ba/Ca ratios were studied through time. Despite stable conditions (temperature, salinity, and Mg/Cawater) for clams reared at salinity 35 during the experiment, Mg/Ca shell ratios increased through the time. Moreover the salinity decrease at t35 slowed the increase of... |
| Tipo: Text |
Palavras-chave: Ruditapes philippinarum; Aragonite; Sclerochronology; Bivalved mollusk; Trace element; Proxy. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00245/35649/34158.pdf |
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| Thomson, J; Crudeli, D; De Lange, Gj; Slomp, Cp; Erba, E; Corselli, C; Calvert, Se. |
| High relative concentrations of the lower photic zone nannofossil Florisphaera profunda have been reported in all recent eastern Mediterranean sapropels. In the most recent sapropel (S1), high bulk sediment Sr/Ca ratios occur along with high F. profunda contents toward the base of the unit, exemplified here in four cores from 1.5-3.5 km water depth. Co-occurring biogenic carbonates contain insufficient Sr to account for these high Sr concentrations, and X-ray diffraction and selective leaching show that the high Sr/Ca ratios are due to aragonite, the CaCO3 polymorph that is rarely preserved in deep marine sediments, with similar to1 wt % Sr. The possible sources of this aragonite include ( 1) precipitation with surface ocean production, ( 2) detrital input... |
| Tipo: Text |
Palavras-chave: Sapropel; Aragonite; Strontium. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00229/33975/32412.pdf |
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| Jorry, Stephan; Jouet, Gwenael; Edinger, Evan N.; Toucanne, Samuel; Counts, John W.; Miramontes, Elda; Courgeon, Simon; Riveiros, Natalia Vázquez; Le Roy, Pascal; Camoin, Gilbert F.. |
| Over the past ten years, a huge amount of source-to-sink studies have aimed to unravel the tectonic, climatic and other processes that shape the landscape from mountains to the deep ocean. Interestingly, these studies have been mainly dedicated to siliciclastic or mixed systems, for which the connection between drainage basins, continental shelves, slope and basin environments are often well constrained. Here we present a study focusing on a source-to-sink study dedicated to a pure carbonate system, located in the SW Indian Ocean (Glorieuses archipelago). Extensive field sampling and geophysical acquisition across the carbonate platform have allowed us to estimate the composition, the lateral variability, and volumes of neritic sands deposited on the... |
| Tipo: Text |
Palavras-chave: Carbonate platform; Coral reef; Calciturbidite; Aragonite; Carbonate budget; Indian Ocean. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00607/71879/70574.pdf |
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| Gerard, Emmanuelle; De Goeyse, Siham; Hugoni, Mylene; Agogue, Helene; Richard, Laurent; Milesi, Vincent; Guyot, Francois; Lecourt, Lena; Borensztajn, Stephan; Joseph, Marie-beatrice; Leclerc, Thomas; Sarazin, Gerard; Jezequel, Didier; Leboulanger, Christophe; Ader, Magali. |
| Lake Dziani Dzaha is a thalassohaline tropical crater lake located on the "Petite Terre" Island of Mayotte (Comoros archipelago, Western Indian Ocean). Stromatolites are actively growing in the shallow waters of the lake shores. These stromatolites are mainly composed of aragonite with lesser proportions of hydromagnesite, calcite, dolomite, and phyllosilicates. They are morphologically and texturally diverse ranging from tabular covered by a cauliflower-like crust to columnar ones with a smooth surface. High-throughput sequencing of bacterial and archaeal 16S rRNA genes combined with confocal laser scanning microscopy (CLSM) analysis revealed that the microbial composition of the mats associated with the stromatolites was clearly distinct from that of the... |
| Tipo: Text |
Palavras-chave: Stromatolites; Alkaline lake; Pleurocapsales; Mg-silicate; Alphaproteobacteria; Anoxygenic phototrophic bacteria; Aragonite; Hydromagnesite. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00443/55451/56970.pdf |
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| Trinkler, Nolwenn; Bardeau, Jean-francois; Marin, Frederic; Labonne, Maylis; Jolivet, Aurelie; Crassous, Philippe; Paillard, Christine. |
| The mineral phase of shell repair in the Manila clam Venerupis philippinarum affected by brown ring disease (BRD) was characterised at various scales and at various stages of shell repair by confocal Raman microspectrometry and scanning electron microscopy. Spherulitic and quadrangular aragonite microstructures associated with polyene pigments were clearly observed. Von Kossa staining showed that at the beginning of shell repair, hemocytes are filled with insoluble calcium carbonate salts in all fluids and then are transported toward the extrapallial fluids and the repair sites. Our analyses suggest that after a Vibrio tapetis attack and BRD deposit some clams rapidly cover the deposit, resulting in a modification in the microstructure, which could be... |
| Tipo: Text |
Palavras-chave: Aragonite; Hemocytes; Shell microstructure; Calcium carbonate; Biomineralization; Mollusc; Raman microspectrometry; Scanning electron microscopy. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00029/14065/11301.pdf |
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| Grau-Crespo, R.; Ruiz-Hernández, S. E.; Ruiz-Salvador, A. R.; De Leeuw, N. H.. |
| We have investigated the thermodynamics of mixing between aragonite (orthorhombic CaCO3) and strontianite (SrCO3). In agreement with experiment, our simulations predict that there is a miscibility gap between the two solids at ambient conditions. All SrxCa1 xCO3 solids with compositions 0.12 < x < 0.87 are metastable with respect to separation into a Ca-rich and a Sr-rich phase. The concentration of Sr in coral aragonites (x 0.01) lies in the miscibility region of the phase diagram, and therefore formation of separated Sr-rich phases in coral aragonites is not thermodynamically favorable. The miscibility gap disappears at around 380 K. The enthalpy of mixing, which is positive and nearly symmetric with respect to x = 0.5, is the dominant... |
| Tipo: Journal Contribution |
Palavras-chave: 1246; Aragonite; Coral reefs; Thermodynamic activity; Strontium; Strontium. |
| Ano: 2010 |
URL: http://hdl.handle.net/1834/4103 |
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| Jolivet, Aurelie; Bardeau, J.f.; Fablet, Ronan; Paulet, Y.m.; De Pontual, Helene. |
| It is generally accepted that the formation of otolith microstructures (L- and D-zones) and in particular the organic and mineral fractions vary on a daily basis. Raman microspectrometry provides a nondestructive technique that can be used to provide structural information on organic and mineral compounds. We applied it to thin otolith sections of hake in order to address the following issues: (1) the simultaneous characterization of variations in the organic and mineral fractions both in the core area and along successive otolith microstructures; (2) elucidation of significant differences between these fractions; (3) quantification of the effects of etching and staining protocols on otolith structures. The primordium appeared as a punctual area depicting... |
| Tipo: Text |
Palavras-chave: Acid etching; Staining; Aragonite; L and D zones; Core. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4355.pdf |
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