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Résumé de la présentation

A major challenge in Earth sciences is quantifying geochemical cycles, including carbon and hydrogen cycles, at a geodynamic scale. Over geological timescales, these cycles have played a pivotal role in regulating climate and habitability throughout Earth's history.

Mid-ocean ridges, where new oceanic lithosphere forms, play a key role in these cycles. Magmatic degassing releases CO₂ into the ocean, while carbonation—CO₂ uptake during hydrothermal alteration—has significant implications for deep Earth carbon sequestration. Additionally, serpentinization, driven by hydrothermal fluid interactions with lithospheric rocks, generates H₂ and abiotic CH₄.

The products of these interactions strongly depend on the dynamics of the mid-ocean ridge and the composition of the lithosphere rocky foundation. However, major uncertainties remain in constraining the distribution of rock types and the extent of their alteration in newly formed oceanic lithosphere. These knowledge gaps hinder a comprehensive understanding of the oceanic lithosphere’s role in geochemical cycling.

Geodynamic modeling is a powerful tool for studying mid-ocean ridge evolution, linking present-day configuration to their geological history. However, simulating fluid-magma-rock interactions remains a challenge.

A promising approach to address this challenge is the development of coupled numerical models that integrate petrological, geological, and geophysical data.