WP1 – Upper crust: We sampled quartz veins in a skarn deposit (Serifos, Greece), in slates along the coastline of Almograve, Portugal, and a section from slates to high-grade gneisses in the Agly Massif to study crustal fluid flow. Together with WP5, we developed numerically consistent models of fluid mixing in fracture networks to estimate porosity and permeability changes, which could be adapted by other ESRs. We also began estimating fluid compositions trapped in quartz veins through fluid inclusions, 40Ar/39Ar dating, and experimental data.
WP2 – Middle crust: We examined mid-crustal levels dominated by ductile processes in quartz- and feldspar-rich rocks, where hydrous fluids alternated between subcritical and supercritical states. Sub-solidus conditions generally prevailed except in crystallizing magmas and contact aureoles. WP2 focused on granitoid magma emplacement, and constraints on fluid flow time- and length scales started to emerge.
WP3 – Lower crust: We investigated crustal levels where supersolidus conditions prevailed in mica-rich lithologies with regional partial melting, mainly migmatites and granulites. Before and after peak temperatures, subsolidus conditions dominated, implying sequences from fluid-dominated to melt-dominated and back to fluid-dominated processes. This complexity required multiple approaches to reconstruct events.
WP4 – Improving the Toolbox: This WP acquired data from natural materials (WP1–3) and experiments. We targeted fluid sources via halogens in inclusions, isotopic signatures, phase reactivity, fluid-flow timescales, and drone photogrammetry for vein distribution. We applied micro-chemical and triple halogen analyses, hydrothermal experiments for porosity-related mineral formation, and microthermometry to determine trapping conditions. We also used step-wise crushing, single-grain fusion, in-situ dating, 40Ar/39Ar geochronology, and noble gas geochemistry to evaluate fluid mobility timescales.
WP5 – Modelling and validation: We focused on data utilization through numerical, database, observational, and experimental methods. Jointly with WP1, we developed models of fluid mixing in fracture networks to estimate porosity and permeability changes, which could be applied by other ESRs.
Fundamental outcomes of the FluidNET effort can be summarized as fluid mobility is periodic, short and pulsed. Chemical interaction as demonstrated in laboratory simulations are found to be fast.
Exploitation of FluidNET results will evolve over time: industry Beneficiaries and Partner Organizations benefitted from fast track dissemination within the ITN as communicated during the Research in Progress meetings. FluidNET provided opportunities for each ESR to communicate results at major international geoscience conferences. FluidNET members organized a symposium during the 2023 EGU conference, creating a platform for interaction with the wider geoscience community. The team also organized a Science Conference inviting prominent external researchers and Advisory Board members, while providing travel and registration grants to early stage researchers outside the ITN.
The dissemination of FluidNET results matches the team’s stage: several ESRs have already defended dissertations, and most others are in the final stages of preparation. All reported materials are published Open Access using ZENODO as the central hub for dissemination (
https://zenodo.org/communities/fluidnet-itn/(s’ouvre dans une nouvelle fenêtre)).
