24 research outputs found

    Preparation of mollusc larval shells for individual geochemical analysis v1

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    This protocol describes the digestion process of mollusc larvae and is modified from the procedure found in Becker et al. (2005). Here, we indicate the entire process to obtain the digestion solution, as well as cleaning glassware, actual larval digestion and extraction of shells until storage for subsequent geochemical analysis or observation. This protocol is applicable to shelly larvae of any species, once they are collected and brought to the laboratory. The goal of this preparation is to isolate each larval shell to perform individual geochemical analyses, instead of dissolving several specimens for bulk analysis. To do this, great care needs to be taken to the handling of the shells using ultra-pure solutions and acid-washed glassware to avoid chemical contamination of all kind. Reference: Becker, B.J., Fodrie, F.J., McMillan, P.A., Levin, L.A., 2005. Spatial and temporal variation in trace elemental fingerprints of mytilid mussel shells: a precursor to invertebrate larval tracking. Limnology and Oceanography, 50, 48-61. doi: 10.4319/lo.2005.50.1.0048

    AERYN: A simple standalone application for visualizing and enhancing elemental maps

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    International audienceInterpretation of high spatial resolution elemental mineral maps can be hindered by high frequency fluctuations, as well as by strong naturally-occurring or analytically-induced variations. We have developed a new standalone program named AERYN (Aspect Enhancement by Removing Yielded Noise) to produce more reliable element distribution maps from previously reduced geochemical data. The program is Matlab-based, designed with a graphic user interface and is capable of rapidly generating elemental maps from data acquired by a range of analytical techniques. A visual interface aids selection of appropriate outlier rejection and drift-correction parameters, thereby facilitating recognition of subtle elemental fluctuations which may otherwise be obscured. Examples of use are provided for quantitative trace element maps acquired using both laser ablation (LA-) ICP-MS and electron probe microanalysis (EPMA) of the cold-water coral Lophelia pertusa. We demonstrate how AERYN allows recognition of high frequency elemental fluctuations, including those which occur perpendicular to the maximum concentration gradient. Such data treatment compliments commonly used processing methods to provide greater flexibility and control in producing elemental maps from micro-analytical techniques

    Geochemistry of Bivalve Shells As Indicator of Shore Position of the 2nd Century BC

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    International audienceIn an area named Mermian (municipality of Agde, South of France), a significant amount of fragmented italic amphorae from the 2 nd century BC was discovered, located at a depth of 6 to 8 meters under the bed of the HĂ©rault river. As no ship wreck was found in the vicinity, the reason of the presence of these amphora fragments, whose faces present a large accumulation of oyster shells, is unknown. Reconstructed geomorphological maps of the area present Mermian as a riverine site already at this period, and several hypothetical explanations on the role of these amphorae exist (landfill linked to a neighbouring habitat, bank reinforcement linked to a ford crossing, river landing, etc.). In order to define whether the amphorae were transported to this location and from where, we analysed the stable carbon and oxygen isotopes of the oyster shells. The ÎŽ 13 C and ÎŽ 18 O indicate that all oysters lived in the same environment, refuting a potential transport during the oyster accumulation. Moreover, the analysis of Mytilaster sp. shells in the sediment around the oyster shells also reported a marine origin, suggesting that these oysters were also buried in a marine deposit. Transport to Mermian from a coastal locality is unlikely but may still have happened, although no trace of human handling were observed on the fragments. Still, the presence of other marine or brackish molluscs in the sediment discards the interpretation of Mermian being a continental locality

    Le site subaquatique de Mermian (Agde, Hérault) : enrochement et amas de céramiques dans le fleuve Hérault à la fin de l'ùge du Fer

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    International audienceA dive carried out in 2004, as part of an archaeological prospecting program of the HĂ©rault river, led to the discovery in a locality known as Mermian of a scattering of Italic amphorae fragments at a depth of between 6 and 8 meters. This singular discovery, added to several testimonies of an old shipwreck looting in the surrounding area subsequently motivated the realization of prospecting campaigns between 2008 and 2009, followed in 2015 and 2016 by two successive campaigns of archaeological surveys. At the end of the latter, it appeared that despite the presence of actual traces of looting on the site, the initial hypothesis of the presence of an ancient shipwreck should be discarded for the moment. The soundings carried out indicate the existence of a large dumping ground for Italic or Greco-Italic amphorae fragments (18 m2 / 30-40 cm thick) which could thus be the cause of confusion in the interpretation of the site. Despite this observation, the reasons for such an accumulation of artefacts in this part of the river remain very uncertain, especially since the paleoenvironment of the site raises many questions.Une plongĂ©e rĂ©alisĂ©e en 2004, dans le cadre d’un programme de prospection archĂ©ologique du fleuve HĂ©rault, a permis la dĂ©couverte au lieu-dit Mermian d’un Ă©pandage de fragments d’amphores italiques Ă  une profondeur comprise entre 6 et 8 mĂštres. Cette dĂ©couverte singuliĂšre, ajoutĂ©e Ă  plusieurs tĂ©moignages d’un ancien pillage d’épave dans ses environs, ont par la suite motivĂ© la rĂ©alisation de campagnes de prospection entre 2008 et 2009, suivies en 2015 et 2016 de deux campagnes successives de sondages archĂ©ologiques. Au terme de ces derniĂšres, il est apparu qu’en dĂ©pit de la prĂ©sence de traces effectives d’un ancien pillage sur le site, l’hypothĂšse initiale de la prĂ©sence d’une Ă©pave antique devait ĂȘtre pour l’instant Ă©cartĂ©e. Les sondages rĂ©alisĂ©s indiquent en effet l’existence d’un important dĂ©potoir de fragments d’amphores italiques ou grĂ©co-italiques (18 m2 / 30 - 40 cm d’épaisseur) qui pourrait ĂȘtre ainsi Ă  l’origine d’une confusion dans l’interprĂ©tation du site. MalgrĂ© ce constat, les raisons d’une telle accumulation de mobilier en cet endroit du fleuve demeurent encore trĂšs incertaines, et ce d’autant que le palĂ©oenvironnement du site soulĂšve bien des interrogations

    Le site subaquatique de Mermian (Agde, Hérault) : enrochement et amas de céramiques dans le fleuve Hérault à la fin de l'ùge du Fer

    No full text
    International audienceA dive carried out in 2004, as part of an archaeological prospecting program of the HĂ©rault river, led to the discovery in a locality known as Mermian of a scattering of Italic amphorae fragments at a depth of between 6 and 8 meters. This singular discovery, added to several testimonies of an old shipwreck looting in the surrounding area subsequently motivated the realization of prospecting campaigns between 2008 and 2009, followed in 2015 and 2016 by two successive campaigns of archaeological surveys. At the end of the latter, it appeared that despite the presence of actual traces of looting on the site, the initial hypothesis of the presence of an ancient shipwreck should be discarded for the moment. The soundings carried out indicate the existence of a large dumping ground for Italic or Greco-Italic amphorae fragments (18 m2 / 30-40 cm thick) which could thus be the cause of confusion in the interpretation of the site. Despite this observation, the reasons for such an accumulation of artefacts in this part of the river remain very uncertain, especially since the paleoenvironment of the site raises many questions.Une plongĂ©e rĂ©alisĂ©e en 2004, dans le cadre d’un programme de prospection archĂ©ologique du fleuve HĂ©rault, a permis la dĂ©couverte au lieu-dit Mermian d’un Ă©pandage de fragments d’amphores italiques Ă  une profondeur comprise entre 6 et 8 mĂštres. Cette dĂ©couverte singuliĂšre, ajoutĂ©e Ă  plusieurs tĂ©moignages d’un ancien pillage d’épave dans ses environs, ont par la suite motivĂ© la rĂ©alisation de campagnes de prospection entre 2008 et 2009, suivies en 2015 et 2016 de deux campagnes successives de sondages archĂ©ologiques. Au terme de ces derniĂšres, il est apparu qu’en dĂ©pit de la prĂ©sence de traces effectives d’un ancien pillage sur le site, l’hypothĂšse initiale de la prĂ©sence d’une Ă©pave antique devait ĂȘtre pour l’instant Ă©cartĂ©e. Les sondages rĂ©alisĂ©s indiquent en effet l’existence d’un important dĂ©potoir de fragments d’amphores italiques ou grĂ©co-italiques (18 m2 / 30 - 40 cm d’épaisseur) qui pourrait ĂȘtre ainsi Ă  l’origine d’une confusion dans l’interprĂ©tation du site. MalgrĂ© ce constat, les raisons d’une telle accumulation de mobilier en cet endroit du fleuve demeurent encore trĂšs incertaines, et ce d’autant que le palĂ©oenvironnement du site soulĂšve bien des interrogations

    Le site subaquatique de Mermian (Agde, Hérault) : enrochement et amas de céramiques dans le fleuve Hérault à la fin de l'ùge du Fer

    No full text
    International audienceA dive carried out in 2004, as part of an archaeological prospecting program of the HĂ©rault river, led to the discovery in a locality known as Mermian of a scattering of Italic amphorae fragments at a depth of between 6 and 8 meters. This singular discovery, added to several testimonies of an old shipwreck looting in the surrounding area subsequently motivated the realization of prospecting campaigns between 2008 and 2009, followed in 2015 and 2016 by two successive campaigns of archaeological surveys. At the end of the latter, it appeared that despite the presence of actual traces of looting on the site, the initial hypothesis of the presence of an ancient shipwreck should be discarded for the moment. The soundings carried out indicate the existence of a large dumping ground for Italic or Greco-Italic amphorae fragments (18 m2 / 30-40 cm thick) which could thus be the cause of confusion in the interpretation of the site. Despite this observation, the reasons for such an accumulation of artefacts in this part of the river remain very uncertain, especially since the paleoenvironment of the site raises many questions.Une plongĂ©e rĂ©alisĂ©e en 2004, dans le cadre d’un programme de prospection archĂ©ologique du fleuve HĂ©rault, a permis la dĂ©couverte au lieu-dit Mermian d’un Ă©pandage de fragments d’amphores italiques Ă  une profondeur comprise entre 6 et 8 mĂštres. Cette dĂ©couverte singuliĂšre, ajoutĂ©e Ă  plusieurs tĂ©moignages d’un ancien pillage d’épave dans ses environs, ont par la suite motivĂ© la rĂ©alisation de campagnes de prospection entre 2008 et 2009, suivies en 2015 et 2016 de deux campagnes successives de sondages archĂ©ologiques. Au terme de ces derniĂšres, il est apparu qu’en dĂ©pit de la prĂ©sence de traces effectives d’un ancien pillage sur le site, l’hypothĂšse initiale de la prĂ©sence d’une Ă©pave antique devait ĂȘtre pour l’instant Ă©cartĂ©e. Les sondages rĂ©alisĂ©s indiquent en effet l’existence d’un important dĂ©potoir de fragments d’amphores italiques ou grĂ©co-italiques (18 m2 / 30 - 40 cm d’épaisseur) qui pourrait ĂȘtre ainsi Ă  l’origine d’une confusion dans l’interprĂ©tation du site. MalgrĂ© ce constat, les raisons d’une telle accumulation de mobilier en cet endroit du fleuve demeurent encore trĂšs incertaines, et ce d’autant que le palĂ©oenvironnement du site soulĂšve bien des interrogations

    Data for the publication by Mouchi et al "A step towards measuring connectivity in the deep-sea: elemental fingerprints of mollusk larval shells discriminate hydrothermal vent sites"

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    This is the elemental data collected by fsLA-ICP-MS-MS on 600 individual larval shells of the hydrothermal-vent limpet Shinkailepas tollmanni from 14 sites in the Southwest Pacific Ocean. The first column indicates the sample ID corresponding to onship sample during the scientific cruise CHUBACARC (Hourdez & Jollivet, 2019). The second column indicates the S. tollmanni sample ID from the publication of Mouchi et al. Columns 3 to 15 correspond to elemental abundances measured. Column 16 to 18 correspond to the region, area and hydrothermal sites, respectively, for each larval shell. Hourdez, S., Jollivet, D., 2019. CHUBACARC cruise, L’Atalante R/V. doi: 10.17600/18001111
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