chapter  38
4 Pages

Modeling magma ascent

WithA. Ord

Continuum codes are incapable of modeling fracture systems in deforming rocks without making a lot of assumptions about fracture initiation and propagation, hence we are exploring the use of non-continuum or particle codes. Geological systems embody interactions between four components: mechanical, thermal, fluid and chemical. There are significant non-linearities associated with each of the processes, as well as with the coupling mechanisms. A non-continuum computational method is believed to be the only satisfactory way to model numerically the full complexity and non-linearity of such a composite system. We model intrusive behavior by including the elastic/plastic behavior of the magma and the elastic/plastic behavior of the country rock. Local pressure gradients built up within the magma retard magma movement in some areas, and may promote it in others. The intrusion behavior is quite different to classical treatments where the magma is assumed to have no shear strength. Intrusive behavior described through elastic/plastic behavior of the magma and of the country rock does not reflect simple buoyancy. Through the use of such codes in studies of mineralization, we also stand to gain some fundamental understanding in solid and fluid mechanics, particularly in fracture mechanics and damage mechanics, and coupled solid-fluid processes. We need also to couple thermal and chemical processes to explore magmatic-hydrothermal mineralization more fully.