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| Registros recuperados: 10 | |
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| Decitre, S; Deloule, E; Reisberg, L; James, R; Agrinier, P; Mevel, C. |
| [1] Analyses of Li and Li isotopes in serpentinized peridotites have been performed using Thermo-Ionisation Mass Spectrometry (TIMS) and Secondary Ion Mass Spectrometry (SIMS) techniques on samples collected from the southwest Indian Ridge (SWIR). In the bulk samples, Li concentrations range from 0.6 to 8.2 ppm, while whole rock delta(6)Li values range from -2.9 to -14parts per thousand. In situ analyses display a greater range in both Li concentration (0.1-19.5 ppm) and Li isotopic composition ( -27 to +19parts per thousand), with the serpentinized portions having higher Li concentrations than the associated relict phases. These variations may reflect changes in Li partitioning and isotopic fractionation between serpentine and fluid with temperature and... |
| Tipo: Text |
Palavras-chave: Lithium; Isotopes; Geochemical cycle; Oceanic crust; Serpentinization. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/00223/33403/31860.pdf |
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| Momoh, Ekeabino; Cannat, Mathilde; Leroy, Sylvie. |
| Extensive outcrops of serpentinized peridotite in melt‐starved spreading corridors of the ultraslow easternmost Southwest Indian Ridge are hypothesized to be due to slip on successive long‐offset normal faults that alternate polarity (flip‐flop detachment faults). We investigate the nature of the oceanic crust which forms under these conditions, using seismic reflection data acquired during the SISMOSMOOTH 2014 cruise. Using 3‐D binning, the seismic profiles were binned elastically, while three of the profiles shot closely were merged into one to take advantage of the larger air gun source volume. Using a poststack imaging sequence, we observe several types of reflectors at crustal and infracrustal depths, in the axial valley and off‐axis. Correlating our... |
| Tipo: Text |
Palavras-chave: Detachment faulting; Ultra-slow spreading; Serpentinization. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00599/71124/69429.pdf |
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| Mei, Nan; Postec, Anne; Monnin, Christophe; Pelletier, Bernard; Payri, Claude E.; Menez, Benedicte; Frouin, Eleonore; Ollivier, Bernard; Erauso, Gael; Quemeneur, Marianne. |
| High amounts of hydrogen are emitted in the serpentinite-hosted hydrothermal field of the Prony Bay (PHF, New Caledonia), where high-pH (similar to 11), low-temperature (< 40 degrees C), and low-salinity fluids are discharged in both intertidal and shallow submarine environments. In this study, we investigated the diversity and distribution of potentially hydrogen-producing bacteria in Prony hyperalkaline springs by using metagenomic analyses and different PCR-amplified DNA sequencing methods. The retrieved sequences of hydA genes, encoding the catalytic subunit of [FeFe]-hydrogenases and, used as a molecular marker of hydrogen-producing bacteria, were mainly related to those of Firmicutes and clustered into two distinct groups depending on sampling... |
| Tipo: Text |
Palavras-chave: Hydrogen; Microbial diversity; Hydrogen producers; Serpentinization; HydA genes; [FeFe]-hydrogenase; Metagenomics. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00467/57913/60308.pdf |
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| Postec, Anne; Quemeneur, Marianne; Bes, Meline; Mei, Nan; Benaissa, Fatma; Payri, Claude; Pelletier, Bernard; Monnin, Christophe; Guentas-dombrowsky, Linda; Ollivier, Bernard; Gerard, Emmanuelle; Pisapia, Celine; Gerard, Martine; Menez, Benedicte; Erauso, Gael. |
| Active carbonate chimneys from the shallow marine serpentinizing Prony Hydrothermal Field were sampled 3 times over a 6 years period at site ST09. Archaeal and bacterial communities composition was investigated using PCR-based methods (clone libraries, Denaturating Gel Gradient Electrophoresis, quantitative PCR) targeting 16S rRNA genes, methyl coenzyme M reductase A and dissimilatory sulfite reductase subunit B genes. Methanosarcinales (Euryarchaeota) and Thaumarchaea were the main archaeal members. The Methanosarcinales, also observed by epifluorescent microscopy and FISH, consisted of two phylotypes that were previously solely detected in two other serpentinitzing ecosystems (The Cedars and Lost City Hydrothermal Field). Surprisingly, members of the... |
| Tipo: Text |
Palavras-chave: Hydrothermal; Serpentinization; Alkaline; Prony; Microbial communities. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00467/57916/60307.pdf |
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| Pisapia, Celine; Gerard, Emmanuelle; Gerard, Martine; Lecourt, Lena; Lang, Susan Q.; Pelletier, Bernard; Payri, Claude E.; Monnin, Christophe; Guentas, Linda; Postec, Anne; Quemeneur, Marianne; Erauso, Gael; Menez, Benedicte. |
| Despite their potential importance as analogs of primitive microbial metabolisms, the knowledge of the structure and functioning of the deep ecosystems associated with serpentinizing environments is hampered by the lack of accessibility to relevant systems. These hyperalkaline environments are depleted in dissolved inorganic carbon (DIC), making the carbon sources and assimilation pathways in the associated ecosystems highly enigmatic. The Prony Bay Hydrothermal Field (PHF) is an active serpentinization site where, similar to Lost City (Mid-Atlantic Ridge), high-pH fluids rich in H-2 and CH4 are discharged from carbonate chimneys at the seafloor, but in a shallower lagoonal environment. This study aimed to characterize the subsurface microbial ecology of... |
| Tipo: Text |
Palavras-chave: Serpentinization; Alkaline hydrothermalism; Deep life; Firmicutes; Acetothermia; Omnitrophica; Organic carbon. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00467/57909/60314.pdf |
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| Mugler, C.; Jean-baptiste, P.; Perez, Florian; Charlou, Jean-luc. |
| The production of hydrogen by serpentinization in ultramafic-hosted hydrothermal systems is simulated by coupling thermodynamic and dynamic modeling in the framework of a thermo-hydraulic single-pass model where a high-temperature hydrothermal fluid moves preferentially through a main canal of high permeability. The alteration of ultramafic rocks is modeled with a first-order kinetic formulation, wherein the serpentinization rate coefficient, Kr, takes the form: Kr = A exp(−α(T − T0)2). In this formulation, α determines the temperature range of the reaction and T0 is the temperature at which the serpentinization rate reaches its maximum. This model is applied to the Rainbow hydrothermal system, which is situated on the Mid-Atlantic Ridge, and characterized... |
| Tipo: Text |
Palavras-chave: First-order kinetic law; Hydrothermal system; Rainbow vent site; Reaction rate; Serpentinization. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00314/42514/41906.pdf |
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| Eickenbusch, Philip; Takai, Ken; Sissman, Olivier; Suzuki, Shino; Menzies, Catriona; Sakai, Sanae; Sansjofre, Pierre; Tasumi, Eiji; Bernasconi, Stefano M.; Glombitza, Clemens; Jorgensen, Bo Barker; Morono, Yuki; Lever, Mark Alexander. |
| Serpentinitic systems are potential habitats for microbial life due to frequently high concentrations of microbial energy substrates, such as hydrogen (H-2), methane (CH4), and short-chain organic acids (SCOAs). Yet, many serpentinitic systems are also physiologically challenging environments due to highly alkaline conditions (pH > 10) and elevated temperatures (>80 degrees C). To elucidate the possibility of microbial life in deep serpentinitic crustal environments, International Ocean Discovery Program (IODP) Expedition 366 drilled into the Yinazao, Fantangisfia, and Asut Tesoru serpentinite mud volcanoes on the Mariana Forearc. These mud volcanoes differ in temperature (80, 150, 250 degrees C, respectively) of the underlying subducting slab, and... |
| Tipo: Text |
Palavras-chave: Limits of life; Deep biosphere; Serpentinization; Abiotic synthesis; Formate; Acetate; Methane; International Ocean Discovery Program. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00637/74919/75981.pdf |
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| Andreani, Muriel; Escartin, Javier; Delacour, Adelie; Ildefonse, Benoit; Godard, Marguerite; Dyment, Jerome; Fallick, Anthony E.; Fouquet, Yves. |
| Rainbow is a dome-shaped massif at the 36°14′N nontransform offset along the Mid-Atlantic Ridge. It hosts three ultramafic-hosted hydrothermal sites: Rainbow is active and high temperature; Clamstone and Ghost City are fossil and low temperature. The MoMARDREAM cruises (2007, 2008) presented here provided extensive rock sampling throughout the massif that constrains the geological setting of hydrothermal activity. The lithology is heterogeneous with abundant serpentinites surrounding gabbros, troctolites, chromitites, plagiogranites, and basalts. We propose that a W dipping detachment fault, now inactive, uplifted the massif and exhumed these deep-seated rocks. Present-day deformation is accommodated by SSW-NNE faults and fissures, consistent with oblique... |
| Tipo: Text |
Palavras-chave: Rainbow; Hydrothermal; Serpentinization; Atlantic ridge. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00210/32151/30609.pdf |
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| Registros recuperados: 10 | |
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