Project description
New model for fluid flow in the Earth interior
The transformation of crustal rocks during burial and heating generates fluids which play an important role for earthquake generation, magmatism, crustal growth and global geochemical cycles. Despite recent efforts, it remains challenging to recognise and quantify fluid fluxes in natural rocks and to model fluid pathways. The EU-funded PROMOTING project will study these fluids using new computer simulation. The models will be nourished and enriched with data obtained using new high-resolution imaging techniques for rock analysis. This project will also produce the first computer model for metamorphism, integrating element mobility from rock scale to crustal sections. Existing models are based on thermodynamic analysis of single-rock types. Also, they do not take into consideration the chemical changes caused by fluid expulsion and interactions with other rocks are not factored in.
Objective
Prograde metamorphism produces large amounts of fluids that have an important role for earthquake generation, arc magmatism, the growth of continental crust and for global geochemical cycles. Despite recent efforts, it remains challenging to recognize and quantify fluid fluxes in natural rocks and to model fluid pathways. The existing petrological modeling techniques are all based on the thermodynamic analysis of single rock types and neglect the chemical changes caused by fluid expulsion and the possible interactions with other rocks. The next frontier in metamorphic petrology is therefore to move our modeling capabilities from an isolated single rock system to an open and multi rock system, in which fluids can flow in, react and flow out. This concept introduces several challenges from the quantification of fluid-rock interactions in natural samples to the integration of aqueous thermodynamics and fluid dynamics in the petrological models. Based on the developments of high-resolution techniques such as quantitative compositional mapping, I have demonstrated that the petrological models can be inverted to quantify prograde metamorphism based on preserved mineral relics that partially re-equilibrated in the presence of fluids. The primary objective of PROMOTING is to develop a brand-new framework for petrological modeling of fluid-rock interactions in different, coupled rock types during prograde metamorphism. The models will be calibrated on two key tectonic settings that shaped Earth: subduction of oceanic crust and differentiation of the continental crust. A cutting-edge petrochronological strategy is required to identify at which conditions and when fluid-rock interactions occurred in natural rocks. The outcomes of this project will not only form the basis for a new generation of models integrating element mobility from rock scale to crustal sections, but they will also bring new constraints to test the validity of the most advanced subduction models.
Fields of science
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Funding Scheme
ERC-STG - Starting GrantHost institution
3012 Bern
Switzerland