A computational Discrete Element Model (DEM) is developed to investigate the kinematic evolution of erosive and non-erosive doubly vergent wedges, focusing on the implications for the interpretation of field data. Many current field studies focus on attempting to identify a positive correlation between tectonic and surface processes. Techniques and observations include thermochronometry, geobarometry, geomorphology, structural reconstruction and syn-tectonic stratigraphy. In order to further constrain the evolution, analogue and computational modelling is required. Modelling studies include analogue sandbox models and computational Finite Element Models (FEMs). Analogue models generate many emergent structural features, but cover a small range of parameter space and have poor reproducibility. FEMs provide poor structural resolution due to underlying continuum assumptions in their formation, but are effective investigating a wider range of parameter space, boundary conditions and erosive feedbacks. The DEM provides the opportunity to build on the best parts of both techniques, providing structural resolution on the sub-orogen scale. This thesis investigates the possibility that some of the discrepancies in the results may be resolved by basing the interpretation of this data on a DEM computational model that allows the emergence of displacements across discrete structures. In order to achieve this, the thesis develops the DEM, highlighting the importance of formulating appropriate boundary conditions and emergent material properties. The role of particle shape, packing structure and inter-particle force parameterisation is investigated using angle of repose and singly vergent wedge experiments. Particles consisting of clusters of three random sized discs produce results most comparable with sandbox analogues and real accretionary prisms. This thesis provides evidence that the discrepancies in field investigations searching for the erosive-tectonic signal may be masked by these emergent second order tectonic fluctuations.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:659897 |
| Date | January 2004 |
| Creators | Naylor, Mark |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/12706 |
Page generated in 0.0022 seconds