Publications associées à Géochimie

Spatially Explicit Linkages Between Redox Potential Cycles and Soil Moisture Fluctuations

Andrea Rinaldo, Rizlan Bernier-Latmani, Paolo Benettin, Manon Frutschi, Simiao Wang, Filippo Miele, Mitra Asadollahi

Reduction-oxidation cycles measured through soil redox potential (Eh) are associated with dynamic soil microbial activity. Understanding changes in the composition of, and resource use by, soil microbial communities requires Eh predictability under shiftin ...

American Geophysical Union2023

Diffusion timescale conundrum in contact metamorphism: Oxygen isotope and trace element profiles in dolomite

Anders Meibom, Stéphane Laurent Escrig, Lukas Baumgartner, Florence Bégué

Successful application of diffusion chronometry is based on detailed knowledge of diffusion parameters obtained from laboratory experiments, which also need to be upscaled to be applied to natural samples. While generally applicable, several examples of di ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Isotope Ratio - Discharge Relationships of Solutes Derived From Weathering Reactions

Paolo Benettin

To date, the vast majority of studies seeking to link discharge to solute concentrations have been based on representations of fluid age distributions in watersheds that are time-invariant. As increasingly detailed spatial and temporal datasets become avai ...

Amer Journal Science2023

Year-round trace gas measurements in the central Arctic during the MOSAiC expedition

Julia Schmale, Ivo Fabio Beck, Hélène Paule Angot

Despite the key role of the Arctic in the global Earth system, year-round in-situ atmospheric composition observations within the Arctic are sparse and mostly rely on measurements at ground-based coastal stations. Measurements of a suite of in-situ trace g ...

2022

Quantifying Photoinduced Polaronic Distortions in Inorganic Lead Halide Perovskite Nanocrystals

Majed Chergui, Nicola Colonna, Michele Puppin, Giulia Fulvia Mancini, Thomas Charles Henry Rossi, Andre Al Haddad, Dominik Kinschel, Oliviero Cannelli, James Michael Budarz, Ludmila Maria Diniz Leroy

The development of next-generation perovskite-based optoelectronic devices relies critically on the understanding of the interaction between charge carriers and the polar lattice in out-of-equilibrium conditions. While it has become increasingly evident fo ...

2021

Investigating Magma Ocean Solidification on Earth Through Laser‐Heated Diamond Anvil Cell Experiments

Philippe Gillet, Cécile Hébert, Marco Cantoni, James Badro, Farhang Nabiei, Charles-Edouard Boukaré

We carried out a series of silicate fractional crystallization experiments at lower mantle pressures using the laser-heated diamond anvil cell. Phase relations and the compositional evolution of the cotectic melt and equilibrium solids along the liquid lin ...

2021

Dissolved major and trace geochemical dynamics in Antarctic lacustrine systems

Tyler Joe Kohler

Clearwater Mesa Uames Ross Island, northeast Antarctic Peninsula) provides a unique opportunity to study solute dynamics and geochemical weathering in the pristine lacustrine systems of a high latitude environment. In order to determine major controls on t ...

Elsevier2020

Nanoscale mechanism of UO2 formation through uranium reduction by magnetite

Rizlan Bernier-Latmani, Barbora Bártová, Thomas La Grange, Zezhen Pan

Uranium (U) is a ubiquitous element in the Earth's crust at similar to 2 ppm. In anoxic environments, soluble hexavalent uranium (U(VI)) is reduced and immobilized. The underlying reduction mechanism is unknown but likely of critical importance to explain ...

Nature Research2020

Taking the pulse of volcanic eruptions using plagioclase glomerocrysts

Anders Meibom, Stéphane Laurent Escrig, Anders McCarthy, Pierre Vonlanthen

Crystallization timescales in subvolcanic systems and the consequences of interaction between ascending magmas and gases remain largely unconstrained, as do links between these processes and monitoring signals at restless volcanoes. We apply diffusion chro ...

ELSEVIER2020

Enhanced trace element mobilization by Earth's ice sheets

Tyler Joe Kohler

Trace elements sustain biological productivity, yet the significance of trace element mobilization and export in subglacial runoff from ice sheets is poorly constrained at present. Here, we present size-fractionated (0.02, 0.22, and 0.45 mu m) concentratio ...

National Academy of Sciences2020

A modeling approach integrating microbial activity, mass transfer, and geochemical processes to interpret biological assays: An example for PCE degradation in a multi-phase batch setup

Christof Holliger, Julien Maillard, Alexandra Marie Murray

The rate at which organic contaminants can be degraded in aquatic environments is not only dependent upon specific degrading bacteria, but also upon the composition of the microbial community, mass transfer of the contaminant, and abiotic processes that oc ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Convection in Lakes

Alfred Johny Wüest, Damien Bouffard

Lakes and other confined water bodies are not exposed to tides, and their wind forcing is usually much weaker compared to ocean basins and estuaries. Hence, convective processes are often the dominant drivers for shaping mixing and stratification structure ...

2019

Copper sulfide nanoparticles as hole-transporting-material in a fully-inorganic blocking layers n-i-p perovskite solar cells: Application and working insights

Mohammad Khaja Nazeeruddin, Giulia Grancini, Cristina Roldán Carmona, Valentin Ianis Emmanuel Queloz

One of the challenges in the field of perovskite solar cells (PSC) is the development of inorganic hole-transporting-materials (HTM) suitable for solution-processed deposition, in order to have cheaper, more stable and scalable devices. Herein, we report t ...

2019

Phyllomanganate vein-infillings in faulted and Al-poor regoliths of the New Caledonian ophiolite: periodic and sequential crystallization of Ni-asbolane, Alk-birnessite and H-birnessite

Gabrielle Dublet

Mineralogy, chemistry and spatial distribution of phyllomanganates, found in abundance at the bottom of thick Ni-laterite deposits, were established on dislocated vein-infillings showing banded and fibrous patterns (i.e. colloforms with rows of tiny boxwor ...

2019

Modelling of C/Cl isotopic behaviour during chloroethene biotic reductive dechlorination: Capabilities and limitations of simplified and comprehensive models

Julien Maillard, David Hunkeler

Predicting the fate of chloroethenes in groundwater is essential when evaluating remediation strategies. Such predictions are expected to be more accurate when incorporating isotopic parameters. Although secondary chlorine isotope effects have been observe ...

2018

Fe-Ni ideality during core formation on Earth

James Badro

Earth's core is essentially composed of a light-element bearing iron-nickel alloy (Birch 1964). The nickel content in the core has negligible effects on physical properties such as density and compressibility (e.g., Lin et al. 2003; Kantor et al. 2007; Mar ...

MINERALOGICAL SOC AMER2018

Biogeochemical Cycling by a Low-Diversity Microbial Community in Deep Groundwater

Rizlan Bernier-Latmani, Manon Frutschi, Emma Bell, Louise Julia Balmer, Guillaume Sommer, Chen Qian

Olkiluoto, an island on the south-west coast of Finland, will host a deep geological repository for the storage of spent nuclear fuel. Microbially induced corrosion from the generation of sulphide is therefore a concern as it could potentially compromise t ...

Frontiers Media SA2018

Effects of non-uniform vertical constituent profiles on remote sensing reflectance of oligo- to mesotrophic lakes

Alfred Johny Wüest, Damien Bouffard, Vincent Maurice Nouchi

We investigate the impact on remote sensing reflectance by the vertical non-uniformities of water constituents. Reflectance simulated for 210 pairs of in situ measured chlorophyll-a and turbidity profiles (z = 0–20 m) from Lake Geneva are compared to simul ...

2018

Modulation of the endogenous production of protoporphyrin IX in a yeast - based model organism

Georges Wagnières, Emmanuel Louis Arthur Gerelli, Jaroslava Joniová

The main aim of this study was to assess conditions at which simple yeast-based model organism produces maximal levels of protoporphyrin IX (PpIX) after an exogenous administration of its precursor, 5-aminolevulinic acid (ALA), and the ferrous-ion chelator ...

Spie-Int Soc Optical Engineering2017

The Role of Geological Barriers in Achieving Robust Well Integrity

Brice Tanguy Alphonse Lecampion

Wells play a key role in the reduction of greenhouse gas emissions. They are not only a critical element in ensuring the permanent trapping of carbon dioxide (CO2) in deep subsurface permeable formations, but they are also being recognized as an important ...

2017