Membre

@article{Truche2021,

title = {Hydrogen generation during hydrothermal alteration of peralkaline granite},

author = {Laurent Truche and Franck Bourdelle and Stefano Salvi and Nicolas Lefeuvre and Apolline Zug and Emily Lloret},

doi = {10.1016/j.gca.2021.05.048},

year  = {2021},

date = {2021-09-01},

journal = {Geochimica et Cosmochimica Acta},

volume = {308},

pages = {42--59},

publisher = {Elsevier BV},

keywords = {ER4},

pubstate = {published},

tppubtype = {article}

}

@article{Bourdelle2021a,

title = {Evaluation of scanning transmission X-ray microscopy at the Mn L2,3-edges as a potential probe for manganese redox state in natural silicates},

author = {Franck Bourdelle and Emily Lloret and Cyril Durand and Laura Airaghi},

doi = {10.1007/s00269-021-01142-w},

year  = {2021},

date = {2021-03-01},

journal = {Physics and Chemistry of Minerals},

volume = {48},

number = {4},

publisher = {Springer Science and Business Media LLC},

keywords = {ER4},

pubstate = {published},

tppubtype = {article}

}

@article{Bourdelle2021b,

title = {Kaolinite-to-Chlorite Conversion from Si,Al-Rich Fluid-Origin Veins/Fe-Rich Carboniferous Shale Interaction},

author = {Franck Bourdelle and Michel Dubois and Emily Lloret and Cyril Durand and Ahmed Addad and Schéhérazade Bounoua and Sandra Ventalon and Philippe Recourt},

doi = {10.3390/min11080804},

year  = {2021},

date = {2021-07-01},

journal = {Minerals},

volume = {11},

number = {8},

pages = {804},

publisher = {MDPI AG},

keywords = {ER4},

pubstate = {published},

tppubtype = {article}

}

@article{lloret:hal-03771430,

title = {Microbial Substrate Utilization and Vegetation Shifts in Boreal Forest Floors of Western Canada},

author = {Emily Lloret and Sylvie Quideau},

url = {https://hal.archives-ouvertes.fr/hal-03771430},

doi = {10.3389/ffgc.2021.700751},

year  = {2021},

date = {2021-08-01},

urldate = {2021-08-01},

journal = {Frontiers in Forests and Global Change},

volume = {4},

publisher = {Frontiers Media},

note = {ACL},

keywords = {ER4},

pubstate = {published},

tppubtype = {article}

}

@conference{Elmaleh2017,

title = {An experimental approach of asteroidal water-rock interactions: mineral formation in a Fe,Si-rich system under anoxygenic conditions},

author = {Agnes Elmaleh and Florent Caste and Nicolas Menguy and Franck Bourdelle and Alexandre Gloter and Emily Lloret and Rachid Belkhou and Jessica Brest},

year  = {2017},

date = {2017-01-01},

booktitle = {Goldschmidt Conference, 14-18 août 2017, Paris},

abstract = {Water-rock interactions observed in carbonaceous chondrites bear similarities to terrestrial serpentinization1, with, however, specificities that need to be addressed experimentally for the environmental conditions that prevailed on their asteroidal parent bodies to be understood. mixed valent fe-rich serpentines are common, but their mechanisms of formation and the fe oxidation processes under the presumably low t and anoxygenic conditions of asteroids are still poorly understood. we performed syntheses of serpentines with different starting compositions as well as alteration experiments of reduced minerals (olivine and metal). anoxygenic conditions were maintained throughout, and the influence of the addition of mgal2o4 -a minor yet ubiquitous component of chondrites- on fe oxidation was tested. the experimental products and their fe valence state were studied down to the nanometer scale using tem, eels and stxm-xanes at the fe l2,3 edges. a complex partitioning of fe among hydroxide and silicate phases is observed, and two main conclusions can be drawn. first, results from both hydrothermal alteration and synthesis suggest the efficiency of spinel in catalysing the oxidation of aqueous fe2+ by water at low t (60°c), similarly to previous experiments in fe-poor systems2. such processes produce hydrogen that may then have played an important role in the evolution of the parent bodies of chondrites (redox state, abiotic organosynthesis3,4). second, at high fe/si and fe3+ /fetot ratios we observed the crystallization of fe-rich serpentine close to the cronstedtite end-member at room temperature. such a rapid formation of cronstedtite is in good agreement with the association of this mineral to the early stages of aqueous alteration in cm chondrites6,1. implications on terrestrial processes will also be discussed.},

note = {ACTI},

keywords = {ER4},

pubstate = {published},

tppubtype = {conference}

}

@conference{Lloret2017,

title = {Soil formation from mining residues: example of weathering of spoil tips, Hauts-de-France region},

author = {Emily Lloret and Franck Bourdelle and Alexis Verbeke and Régine Mosser-Ruck and Agnes Elmaleh},

year  = {2017},

date = {2017-01-01},

booktitle = {Goldschmidt Conference, 14-18 août 2017, Paris},

abstract = {Spoil tips from coalfield symbolize the past mining and industrial activities of the north of france, becoming a scar in the landscape, classified to world heritage (unesco). they are mining residue storage coming from coal extraction, and are constituted by schists (carbonaceous material, quartz, illite, chlorite, pyrite) and scoria with coal residues. although these materials are considered as sterile, some of them present natural revegetation, the formation of a new soil and a novel ecosystem with pioneer species. moreover, spoil tips could be a source of pollution (e.g. metals, sulphur). all these aspects are either the cause or the consequence of a main process: the weathering of spoil tip bedrock materials. therefore, it is important to study this weathering to better understand relationships between mining residues and ecosystems. we selected two spoil tips with different characteristics: the haillicourt spoil tip (h-st) composed of black schists and presenting a short revegetation by pioneer plants, and the ostricourt spoil tip (o-st) with a similar bedrock material but presenting a strong colonization by a forest. a neoformed soil is clearly observable on o-st (with several horizons), but not really identifiable on h-st. neoformed soils were characterised via fine biogeochemical (ph, c/n ratio) and mineralogical (xrd, stxm-xanes, tem) analysis. products of spoil tip weathering mostly consist in interstratified clays and typical sulphur-bearing minerals (jarosite). these phases are more abundant where the vegetation is very developed. some ferich detrital phyllosilicates (as chlorite) are also identified and have a nanoscale intracrystalline zonation (stxm-xanes) of iron redox, resulting of a lower kinetic of weathering. these mineralogical investigations, coupling to c/n ratios and ph measurements (showing that o-st soils are more acidic than h-st soils), allow to constrain the interaction between revegetation of mining residues and the soil formation, giving important keys for the rational management of spoil tips.},

note = {ACTI},

keywords = {ER4},

pubstate = {published},

tppubtype = {conference}

}

@article{Lloret2016,

title = {Sources of dissolved organic carbon in small volcanic mountainous tropical rivers, examples from Guadeloupe},

author = {Emily Lloret and Céline Dessert and Heather-L. Buss and Carine Chaduteau and Sylvain Huon and Patrick Alberic and Marc-F. Benedetti},

year  = {2016},

date = {2016-01-01},

journal = {Geoderma},

volume = {282},

pages = {129-138},

abstract = {In the tropical zone, small watersheds are affected by intense meteorological events. these events play an important role in the erosion of soils and therefore on the sources of organic carbon in small tropical rivers. we studied the geochemistry of two soils on basse-terre island (french west indies, fwi): ferralitic soil and andosol. the two studied soils are very similar in terms of soil organic matter (som) and soil solution parameters. the total organic carbon (toc) and total nitrogen (tn) contents vary between 1.7 and 92 g kg‐1 and between 0.1 and 5.5 g kg‐1, respectively, with the highest concentrations observed in the topsoil. the c/n ratios are relatively constant throughout the soil profiles (ca. 12). the carbon isotopic composition of som varies between ‐27.3‰ and ‐22.7‰ and presents an enrichment with increasing depth of soil profiles. dissolved organic carbon (doc) concentrations in soil solutions, varying from 3.2 to 91.3 mg l‐1, are similar for the both extraction used in lab (with milliq water and ca(no3)2) but are higher than those measured in soil solutions sampled from lysimeters (0.65–1.46 mg l‐1). the isotopic compositions of doc obtained by extractions and som are comparable, with δ13c values ranging from ‐28.6‰ to ‐25.8‰. the doc sampled from lysimeters is systematically depleted in 13c compared to doc obtained by extractions, with δ13c values of ‐33.8‰ to ‐30.6‰. the enrichment of δ13c of som through the soil profiles is either consistent with the carbon isotopic fractionation of som by decomposing organisms, or the differential mineralization of both labile and stable carbon stocks in soils. doc concentrations in stream waters vary between 0.46 and 5.75 mg l‐1, and are generally lower during low water level than floods. the isotopic compositions of doc in the rivers range from ‐38.9‰ to ‐27.2‰, with δ13c values, which are more depleted in 13c during low water level than flood events. the δ13cdoc of water river samples and soil solutions obtained by extraction and collected with lysimeters demonstrates that the doc in rivers derives essentially from both the lixiviation of the soil surface layers during floods and groundwater flow during low water levels. lixiviation of soil surface layers can be boosted by significant increases of intensity and duration of meteorological events and can strongly favor the release of surface soil organic matter in rivers and the impoverishment in nutrients of soil surface layers.},

note = {ACL},

keywords = {ER4},

pubstate = {published},

tppubtype = {article}

}

@article{Quideau2016,

title = {Extraction and analysis of microbial phospholipid fatty acids in soils},

author = {Sylvie-A. Quideau and Anne-C.S. McIntosh and Charlotte-E. Norris and Emily Lloret and Mathew-J.B. Swallow and Kirsten Hannam},

year  = {2016},

date = {2016-01-01},

journal = {Journal of Visualized Experiments},

volume = {114},

pages = {e54360},

abstract = {Phospholipid fatty acids (plfas) are key components of microbial cell membranes. the analysis of plfas extracted from soils can provide information about the overall structure of terrestrial microbial communities. plfa profiling has been extensively used in a range of ecosystems as a biological index of overall soil quality, and as a quantitative indicator of soil response to land management and other environmental stressors. the standard method presented here outlines four key steps: 1. lipid extraction from soil samples with a single-phase chloroform mixture, 2. fractionation using solid phase extraction columns to isolate phospholipids from other extracted lipids, 3. methanolysis of phospholipids to produce fatty acid methyl esters (fames), and 4. fame analysis by capillary gas chromatography using a flame ionization detector (gc-fid). two standards are used, including 1,2-dinonadecanoyl-sn-glycero-3-phosphocholine (pc(19:0/19:0)) to assess the overall recovery of the extraction method, and methyl decanoate (mec10:0) as an internal standard (istd) for the gc analysis},

note = {ACLO},

keywords = {ER4},

pubstate = {published},

tppubtype = {article}

}

@conference{Quideau2016a,

title = {Microbial utilization of 13C-labelled substrates in boreal forest soils},

author = {Sylvie Quideau and Emily Lloret},

year  = {2016},

date = {2016-01-01},

booktitle = {IsoEcol 2016, Tokyo (Japon)},

note = {ACTI},

keywords = {ER4},

pubstate = {published},

tppubtype = {conference}

}

@article{Dessert2015,

title = {Controls on chemical weathering on a mountainous volcanic tropical island: Guadeloupe (French West Indies)},

author = {Céline Dessert and Eric Lajeunesse and Emily Lloret and Clémentine Clergue and Olivier Crispi and Caroline Gorge and Xavier Quidelleur},

year  = {2015},

date = {2015-01-01},

journal = {Geochimica et Cosmochimica Acta},

volume = {171},

pages = {216-237},

abstract = {Guadeloupe Island is a natural laboratory, ideally suited to the study 

	of biogeochemical processes in tropical and mountainous volcanic 

	environments. The island’s east–west rainfall gradient (1200–8000 

	mm/yr) is superimposed on a north–south age gradient (2.7 Ma to present), 

	providing a unique opportunity to investigate the influence of rainfall 

	and rock age on the chemical weathering of volcanic terrains. Taking 

	advantage of this configuration, we present the first temporal survey 

	(2007–2013) of the geochemical composition of the dissolved load 

	of rain and river waters in Guadeloupe. 

 

	Our data demonstrate that the chemical composition of river water 

	is influenced by rainfall abundance, hydrothermal alteration (from 

	active or fossilized volcanic systems) and interactions between water 

	and minerals during chemical weathering processes. The contribution 

	of rain to the overall chemical balance is especially significant 

	in the older northern part of the island, where the ferralitic soils 

	are base-cation-depleted. Between 15% and 65% of the Ca or Mg riverine 

	budgets comes from atmospheric deposits, highlighting the major role 

	of rainfall in the geochemical budgets of small tropical and mountainous 

	watersheds. The river water dataset indicates that different chemical 

	weathering processes dominate the budget depending on the age of 

	the local bedrock. In the younger, southern part of the island, a 

	pool of easily-weatherable andesitic minerals from the bedrock dominates. 

	The contribution from this pool decreases significantly (to 5–15 

	wt.% of the bulk soil) towards the older terrains in the north. The 

	northern rivers are characterized by low Ca/Mg ratios (0.5–1.0), 

	intermediate between those of fresh rocks (1.7–3.3) and soil (0.1). 

	Weathering in the northern part of the island is therefore dominated 

	by the dissolution of depleted secondary minerals into soils. The 

	Ca/Mg ratio of the river water increases from north to south, eventually 

	reaching values similar to those of the bedrocks, arguing for congruent 

	dissolution of the youngest volcanic rocks. 

 

	The magnesium isotopic composition of river water (δ26Mg) reflects 

	inputs from both rain and weathering processes. In southern and central 

	rivers, the Mg isotopic value of waters after correction for rain 

	inputs (δ26Mgwea) is systematically depleted in heavy isotopes (mean 

	value of −0.34‰) relative to that of the bedrock (−0.24‰ to −0.15‰). 

	In the north, the δ26Mgwea of the river water (−0.09‰) is heavier 

	than that of the andesitic bedrock, possibly reflecting the dissolution 

	of 26Mg-rich secondary minerals (ferralitic soil measured around 

	+0.13‰). The robustness of δ26Mg and Ca/Mg as proxies of the degree 

	of soil weathering should be investigated further via more detailed 

	sampling campaigns in the future. 

 

	By combining high-frequency monitoring of river discharge with measurements 

	of concentration–discharge relationships for a wide range of chemical 

	elements, we estimate the mean annual chemical weathering fluxes 

	for three rivers that belong to the OBSERA critical zone observatory. 

	Fluxes vary from 51.7 to 91.8 t/km2/yr north to south along the bedrock 

	age gradient, and are among the highest recorded in volcanic tropical 

	regions. Flash floods can explain 21–31% of the annual chemical weathering 

	fluxes. The results highlight the importance of monitoring rivers 

	over periods of several years in order to obtain accurate estimates 

	of chemical exports in tropical and mountainous environments.},

note = {ACL},

keywords = {ER4},

pubstate = {published},

tppubtype = {article}

}

@conference{Gauthier2015,

title = {Ecological and geological evolution of coal heap in urban context: what are the impact related facilities and sites overcrowding?},

author = {Arnaud Gauthier and Frederic Kowalski and Emily Lloret and Michel Dubois},

year  = {2015},

date = {2015-01-01},

booktitle = {Soils in Urban, Industrial, Traffic and Mining Areas (SUITMA 8), 20-25 September 2015, Mexico city (Mexico)},

note = {ACTI},

keywords = {ER4},

pubstate = {published},

tppubtype = {conference}

}

@conference{Lloret2015,

title = {Microbial processing of leaf- and root-derived organic matter in the boreal forest},

author = {Emily Lloret and Sylvie Quideau},

year  = {2015},

date = {2015-01-01},

booktitle = {European Geosciences Union General Assembly 2015. 12-17 April 2015, Vienna (Autriche)},

abstract = {Soil microbial composition may vary in response to changes in organic matter inputs or stand compositions. boreal soils from alberta, canada, support a canopy cover of aspen (populus tremoloides michx.), white spruce (picea glauca (moench) voss) or a mixing of these two species. these soils also reflect different biogeochemical processing of organic matter degradation. this study sets out to determine if a simple labelled compound (13c glucose) and more complex labelled litter (13c leaves, or roots) are processed differently by forest floors from these two dominant stand types (aspen and spruce). to examine these effects, we put in place a lab incubation experiment, and added labelled substrates (glucose, roots or leaves) to a small quantity of moistened aspen or spruce forest floor. we measured soil respiration throughout the 67-day incubation, and used phospholipid fatty acids (plfa) analysis to identify the soil microbial structure. by quantifying the incorporation of 13c into different plfas, we were also able to identify functional groups responsible for the metabolism of labelled compounds. the measure of 13c-co2 gave some information about the percent of co2 coming from each added substrate. preliminary results indicate that daily respired co2 fluxes were more important from spruce than from aspen forest floor; this was true for all added substrates. for the spruce samples, co2 fluxes decreased very rapidly during the first four days, and stayed relatively constant during the remainder of the incubation. for the aspen samples, fluxes also decreased very rapidly during the first four days, and decreased more gradually for the rest of the incubation. results also show that both soils rapidly incorporated and respired the simple labelled carbon; indeed, after two days between 40 and 60 % of the added glucose had been respired against only 20 to 30 % for the more complex substrates (roots and leaves). the two soils maintained a distinct microbial community structure throughout the 67-day incubation. while the microbial structure changed during incubation, there was no measurable shift in response to substrate addition (labelled glucose, leaves or roots). finally, results show that the percent of substrate incorporated into microbial plfas was more important for the labelled roots than for the other two labelled substrates (glucose or leaves).},

note = {ACTI},

keywords = {ER4},

pubstate = {published},

tppubtype = {conference}

}

@article{Condomines2014,

title = {(228Ra/226Ra) ratios in hydrothermal carbonates and the origin of radium in CO2-rich waters of the Lodève Basin (South of France)},

author = {Michel Condomines and Emily Lloret and Jean-Luc Seidel and Michel Lopez},

year  = {2014},

date = {2014-01-01},

journal = {Chemical Geology},

volume = {372},

pages = {46-53},

abstract = {The present study reports data on co2-rich geothermal waters and their associated carbonate deposits from the sw part of the permian lodève basin (south of france). both waters and carbonates are enriched in 226ra, with activities up to 2.2 bq/l and 3.5 bq/g respectively. a series of carbonate samples precipitated around the studied wells since 1990 were dated through the 226ra–210pb and 228ra–228th methods, and the results are discussed in a new concordia diagram. while both methods give comparable dates for many samples, ra–pb ages are sometimes much older than ra–th ages. we propose that these discrepancies result from the adsorption of 222rn daughter nuclides in such a rn-rich environment. the (228ra/226ra)0 activity ratios calculated at the time of deposition are remarkably constant for about 12 years, suggesting the presence of a steady-state aquifer. the low (228ra/226ra)0 ratios (0.348 ± 0.008) are best explained if most of the ra derives from the cambrian carbonate series (mainly dolostone) underlying the permian basin, which have low th/u and similar (228ra/226ra) ratios. this study suggests that ra and other alkaline-earth elements do not necessarily originate from the rocks surrounding the deep geothermal reservoir, but rather may be introduced into the co2-rich water during its transfer towards the surface and interaction with carbonate rocks},

note = {ACL},

keywords = {ER4},

pubstate = {published},

tppubtype = {article}

}