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Analogue-Modelling and Section-Balancing |
1 Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
2 Geologisches Institut der TH Darmstadt, Schnittspahnstr, 9, 6100 Darmstadt, Germany
In an attempt to constrain the influence of boundary conditions on fault nucleation and propagation processes, basement-controlled normal faulting has been simulated using analogue clay models and plane-strain finite element models. Two opposing basement configurations were investigated and the results of the analogue and numerical models were compared.
In the first series of clay models subsidence of a basement block along an inclined normal fault and along a vertical fault was simulated. An upwards-propagating fault initiated at the base of the clay model. The final fault geometry was consistent with the geometry of the stress distribution calculated in the finite element model. No listric fault developed.
In the second experiment horizontal basement extension was simulated and, as expected from the numerical calculations, these boundary conditions resulted in the formation of listric faults. The results of the analogue and numerical experiments show that initial fault geometry can be predicted successfully from the stress distribution at the elastic limit.
