Séminaire ISTerre

Elemental transfers at mineral interfaces – from mineral weathering to nutrient availability

mercredi 23 novembre 2022 - 10h00
Bastien Wild  - ISTerre-Séminaire Post-doc
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Mineral interfaces constitute the locus of chemical reactions that are key to the evolution of the Earth system. Fluid confined in nanoporous interfaces exhibits singular properties that can control dissolution and precipitation processes involved in metasomatism and metamorphic reactions, and involved in ductile deformation of the upper crust, fault creep and interseismic healing. Electron transfers at mineral interfaces support the metabolism of deep biosphere microbial communities, while in the most surficial layers of our planet, biofilms and thin fluid films adsorbed at mineral interfaces in the regolith carry reactive species in the form of organic molecules, dissolved ions and gases that drive rock weathering, thereby regulating atmospheric CO2, climate, and pedogenesis and thereby generating bio-essential elements that fuel ecosystem development. Common to this broad range of systems is the need to probe experimentally or numerically the properties of complex fluid-mineral(-microorganism) interfaces. This seminar will highlight a set of recent studies conducted in hydrothermal and surface contexts that aim to disentangle processes driving mineral dissolution. I will show how structural changes probed by surface-sensitive synchrotron techniques at fluid-mineral interfaces can impact mass and energy transfer between the mineral and the bulk fluid, as determined using atomic-scale non-equilibrium molecular dynamics simulations. Moving towards surface environments, we incubated a suite of well-characterized single crystals in soil profiles located at several instrumented sites in France and in the United States to assess the impact of the properties of the fluid flow in unsaturated soil media on local dissolution rates. We combined high resolution microscopy and molecular biology tools to quantitatively compare the relative effect of microbial colonization and the evolution of mineral interfaces on weathering. Finally, I will outline how we intend to further develop this framework in synergy with capabilities available at ISTerre to better understand the production of critical nutrients for surface ecosystems at the fluid-mineral-microorganism nexus.

Equipe organisatrice : Organisation labo

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

“Minimalist seismology”: studying earthquakes with sparse instrumentation

jeudi 17 septembre 2026 - 11h00

Mathieu Causse - ISTerre

Equipe organisatrice : Organisation labo

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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Stable‑to‑dynamic expansion of fault slipping area through fluid injection observed in laboratory experiments using a sub‑meter scale specimen

vendredi 18 septembre 2026 - 14h00

Takatoshi Ito  - Université de Tohoku, Japan

Equipe organisatrice : Mécanique des failles

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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Tectonics, Mantle Dynamics and Coupled Lithosphere-Mantle-Core Evolution of Earth and Other Rocky Worlds

jeudi 24 septembre 2026 - 11h00

Paul Tackley - ETH Zurich

Equipe organisatrice : Grands Séminaires ISTerre

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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Tectonics, Mantle Dynamics and Coupled Lithosphere-Mantle-Core Evolution of Earth and Other Rocky Worlds

jeudi 24 septembre 2026 - 11h00

Paul Tackley - ETH Zurich

Equipe organisatrice : Grands Séminaires ISTerre

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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Apport des expériences analogiques pour la modélisation et le suivi en temps réel de la propagation du magma en profondeur : Exemple du Rift Est Africain

jeudi 1er octobre 2026 - 11h00

Virginie Pinel - ISTerre

Equipe organisatrice : Organisation labo

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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A t-on encore besoin de plaques pour expliquer la tectonique de la vallée du Rhône et des Alpes Occidentales ?

vendredi 2 octobre 2026 - 11h00

philippe VERNANT - Geosciences Montpellier

Equipe organisatrice : Tectonique active et sismicité

Salle Dolomieu, Maison des Géosciences, 38400 Saint Martin d'Hères

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TBA

vendredi 2 octobre 2026 - 14h00

Hugo Boulze - 

Equipe organisatrice : Cycle sismique et déformations transitoires

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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TBA

vendredi 9 octobre 2026 - 11h00

Eric Beaucé - ISTerre

Equipe organisatrice : Cycle sismique et déformations transitoires

Salle Dolomieu, Maison des Géosciences, 38400 Saint Martin d'Hères

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TBA

vendredi 20 novembre 2026 - 11h00

Farzaneh Mohammadi - ENS Paris

Equipe organisatrice : Cycle sismique et déformations transitoires

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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