The localisation of erosional denudation represents the principal mechanism through which compressional mountains systems are exhumed and is a fundamental parameter in their mechanical and geomorphological development. Exhumation gradients within the central Pyrenean interior have been identified by synchronous periods of exhumation and sedimentation. There is no structural or metamorphic evidence to indicate that tectonic denudation in this region has occurred, hence, the distribution of exhumation was principally controlled through spatially heterogeneous surface erosion. The controlling parameters on the spatial variability of erosion in the Pyrenees and the implications for the developing mountain belt are, to date, poorly understood. In this study, spatial and temporal gradients in erosion-driven exhumation within the central Pyrenees are quantified and the mechanisms through which they were generated are investigated. To this aim, a multidisciplinary approach is adopted. Low temperature thermochronology (apatite (U-Th)/He, apatite fission track and zircon fission track) is applied to constrain time-temperature histories and to characterise the regional distribution of exhumation during active orogenesis and during the post-orogenic period. Geological field data from the orogenic interior and form adjacent sedimentary basins is used to provide constraints on the tectonic evolution of the area. Results indicate the history of erosional denudation during and after orogenesis is considerably more complex than previous models envisaged and is governed by a number of discrete physical mechanisms. During active orogenesis, exhumation was controlled by the strongly spatially variable distribution of tectonically-forced rock uplift and the associated control on erosion. During the post-orogenic period, spatial variability in exhumation was maintained, but was principally governed by externally-forced shifts in the evolution and denudation of the Pyrenean landscape.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:651441 |
| Date | January 2004 |
| Creators | Gibson, Matthew |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/14908 |
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