Fault and Deformation Modelling
We pay particular interest to faults. These brittle structures dominate the upper crust of the Earth. They offer, amongst other things, pathways for fluids and are therefore of great interest for e.g., the petroleum industry, the production of geothermal energy and the sequestration of CO2.
An outcrop showing normal faults in upper Triassic 'Keuper', Ütterroda, near Eisenach. Width of the outcrop is 12 m.
An example of retro-deforming a seismic fault, while plotting strain in the hanging-wall
To model the fault movement in three-dimensions, the following is required:
- The morphlogy of the fault surface and the faulted beds around it,
- The fault displacement, as ascertained from 1. and
- the kinematic vector, which can be determined from, e.g., corrugations on the fault surface.
Using the software programme '3DMove', the faulted beds can then be retro-deformed, i.e. moved kinematically on the fault, back to the unfaulted position. The beds can be mapped for strain during the retrodefromation, thus revealing the strain due to faulting. The software determines the orientation and magnitude of the strain tensor, which can be then compared and calibrated against borehole (e.g. fracture density plots) or outcrop data.