Appel à manisfestation d’intérêt – Expédition SPARC « MESMERIC »: MEtal and Sulfur fluxes during Margin Evolution: from RIdge to Continent

Pour mieux comprendre le flux géochimique des métaux lors des phase de rift continental et de l’ouverture océanique, cette expédition « à terre » rassemble une équipe internationale et pluridisciplinaire pour analyser des échantillons collectés lors d’anciennes campagnes de carottage scientifique océanique.

Motivation scientifique (en anglais)

Continental breakup and ocean opening are fundamental processes of the Earth system. They involve progressive thinning of the continental crust, upwelling of asthenospheric mantle and ultimately lead to the formation of new oceanic crust. Throughout this evolution, a tight interplay occurs between tectonism, magmatism, sedimentation and hydrothermal fluid circulation, driving extensive geochemical exchanges between the asthenosphere, lithosphere, hydrosphere and biosphere.

These geochemical fluxes at margins are closely intertwined with ore forming processes and the Sulfur cycle. However, margins are highly diverse and complex, being classified as magma-poor, intermediate or magma-rich. Despite their global significance, the magnitude and nature of large-scale geochemical fluxes at margins remain poorly constrained. Fortunately, geological material recovered by the DSDP, ODP and IODP programs from numerous deep drill cores at continental margins provides unique insight and opportunity to understand geochemical fluxes at margins.

With the MESMERIC project we want to reinvestigate 20 legacy drill cores from:

1) the West Iberian margin and the conjugate Newfoundland margin, representative of magma-poor margins;

2) the South China Sea and the Red Sea margins, representative of intermediate margins;

3) the Norwegian margin, representative of magma-rich margins.

The study of deep drill cores at these margins will allow to gain in-depth insights into the geochemical fluxes of metals (Cu, Zn, Pb, Ni, Co, Au, Ag, Mo, As, Sb, Ge, Ga, In, Se, Te, Bi) and S at margins, especially across the basement-sedimentary interface, which has been little studied so far in this regard.

The MESMERIC project focuses on three main research axes:

1) metal fluxes during margin evolution and the link to ore deposit formation, including Zn-Pb clastic dominated deposits, ultramafic-hosted volcanogenic massive sulfide (VMS) deposits and native Cu deposits,

2) Sulfer cycling throughout margin evolution and the link to ore deposits, bacterial activity and biogenic-abiogenic sulfate-methane reactions,

3) fluid-rock interactions and associated hydrothermal alterations.

The approach of the MESMERIC project is multi-scale and multi-disciplinary combining geochemistry, tectonics, petrology, sedimentology, mineralogy, structural geology, hydrothermalism, geophysics, statistics and ore geology. Combination of state-of-the-art non-destructive and partly destructive methods will allow us to build a unique large database on metal and S concentration and speciation at margins.

The project outcomes and deliverables will provide a unique holistic overview of large-scale processes associated with ore deposit formation as well as in-depth understanding of the S cycle at margins.

Logistique

Les candidatures pour participer à cette expédition seront ouvertes à la fin de l’année 2026. Toutefois, si vous souhaitez être parmi les premiers à recevoir des informations sur cette expédition passionnante, nous invitons les potentiels candidats à remplir le formulaire de manifestation d’intérêt ci-dessous.

Cette démarche n’est pas obligatoire, ne vous engage pas à postuler lors de l’appel principal, et le fait de ne pas remplir ce formulaire n’aura aucune incidence sur l’évaluation de votre candidature ultérieure. Nous vous encourageons toutefois vivement à remplir ce formulaire afin que nous puissions vous accompagner au mieux.