Inversion of a symmetric basin: insights from a comparison between analogue and numerical experiments
M. Panien, S. J. H. Buiter, G. Schreurs, O. A. Pfiffner, 2006. "Inversion of a symmetric basin: insights from a comparison between analogue and numerical experiments", Analogue and Numerical Modelling of Crustal-Scale Processes, S. J. H. Buiter, G. Schreurs
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We use both analogue and numerical experiments to study the inversion by shortening of a symmetric sedimentary basin. The combination of the two modelling techniques uses the strengths of each method to provide insight into basin-inversion processes. The experiments start with a pre-existing basin filled, in part, with weak layers simulating weak sedimentary rocks. Both footwall and hanging wall can deform freely. The physical properties of the materials used in the analogue experiments (sand and microbeads) and the numerical experiments are appropriately scaled to represent upper crustal rocks. We present a systematic study of the effects of basin infill, basin width and basin location and a sensitivity analysis to understand the effects of the boundary conditions. The results of both methods show that the graben fill accommoda tes most shortening. Weak layers play an important role in localising shortening with limited reactivation of pre-existing (but weakened) faults. In general, forward thrusts and back thrusts nucleate at the lateral contrast of strong and weak materials and cut across the graben-bounding faults. Weak basal detachments are required to transfer shortening to the basin region. The overall evolution of the analogue and numerical models is encouragingly similar.
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The crust of the Earth records the deformational processes of the inner Earth and the influence of the overlying atmosphere. The state of the Earth’s crust at any time is therefore the result of internal and external processes, which occur on different time and spatial scales. In recent years important steps forward in the understanding of such complex processes have been made by integrating theory and observations with experimental and computer models. This volume presents state-of-the-art analogue and numerical models of processes that alter the Earth’s crust. It shows the application of models in a broad range of geological problems with careful documentation of the modelling approach used. This volume contains contributions on analogue and numerical sandbox models, models of orogenic processes, models of sedimentary basins, models of surface processes and deformation, and models of faults and fluid flow.