DeMoPlanet: a project to explore deformation as a result of magma intrusion
The DeMoPlanet project is led by Dr Sam Poppe at the Space Research Centre (Polish Academy of Sciences) and funded by the Norwegian Financial Mechanism at the National Science Centre of Poland.
In collaboration with Claire Harnett and other international collaborators, the project aims to use discrete element method (DEM) modelling to investigate deformation and fracturing that occurs in host rock as a result of the injection of magma into a pre-existing magma body (i.e. a laccolith). The project combines fieldwork in trachy-andesite intrusions in the Polish Sudetes, rock mechanics, and modelling to understand how magma intrusion leads to deformation.
The first paper from this study is out now in Journal of Geophysical Research: Solid Earth and can be accessed below:
In this paper, we designed a new 2D model that simulates magma recharge into a pre-existing laccolith intrusion. We explored the effect of host rock stiffness and toughness. High stiffness resulted in extensive cracking of the host rock, with multiple vertical surface fractures propagating from the surface down toward the magma intrusion. For high tougness host rock, we found limited cracking of the host rock, in favour of one central vertical fracture initiated at the surface. This has important implications for surface expression of deformation, both on Earth and on other terrestrial planets.
Figure 2 from the paper: Effect of host rock toughness on the normalized finite shear strain and fracture pattern at 5%, 25%, and 100% of magma injection. The rock toughness was varied by varying the bond tensile strength, while the bond effective modulus was kept constant at 3 GPa for all three simulations shown here. Small black lines perpendicular to broken bonds represent cracks (broken bonds). Strains on all sub-panels are cut off at 0.05% and normalized.
