Constraining the interplay of magmatic and hydrothermal processes during ore formation with numerical models

Future exploration for mineral resources will target greater depths and submarine settings, which is costly and technically challenging. For this development, numerical modeling can be used to identify the governing processes within entire ore-forming systems. Capturing the dynamics of magmatic-hydrothermal interface processes requires to resolve mass and energy fluxes as a continuum that extends beyond the roots of hydrothermal systems and bridges the gaps between fluid flow and magma dynamics. Magma is mobile during intrusion events and can convect until it reaches a crystal lockup due to cooling and crystallization. During this process, the magma reservoir reaches fluid saturation and exsolves metal-bearing magmatic volatiles to the host rock. We developed a consistent formulation for fluid generation and transport in a coupled model for viscous flow according to the Navier-Stokes-Equations and porous flow with Darcy’s Law, using an up-scaled description of volatile release from reservoir to host rock and realistic magma properties from published experimental and modelling works. We explore the consequences of exsolved volatile phases on magma dynamics and its implications on fluid release and ore formation within the host rock. We distinguish three distinct stages during the evolution of magmatic bodies and their associated porphyry copper deposits with a preparation, a brecciation-stockwork-veining and an ore-formation stage.