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Exhumation of metamorphic terranes: introduction

Published online by Cambridge University Press:  05 July 2018

S. J. Cuthbert*
Affiliation:
Biological & Geological Sciences, School of Engineering and Science, University of Paisley, Paisley PA1 2BE, UK
M. Ballévre
Affiliation:
Laboratoire de Pétrologie, Géosciences Rennes, Université de Rennes I, 35042 Rennes Cedex, France

Extract

Ever since the landmark paper by England and Richardson (1977) it has been clear that metamorphic rocks are not merely passively advected towards the surface during unroofing, but respond in a dynamic and interactive way to the mechanisms and rates of exhumation. England and Richardson based their modelling upon erosion-driven exhumation dominated by fluvial processes in mid-latitude climates. Since then a variety of mechanisms has been identified, mostly emphasizing tectonic mechanisms including extensional tectonics (e.g. Platt, 1996), tectonic extrusion (Chemenda et al., 1996; Hynes et al., 1996; Thompson et al., 1997) and ‘gravity currents’ (Wernicke and Getty, 1997). It has also become apparent that exhumation itself may be strongly influenced by metamorphic processes. For example, changes in petrophysical properties such as density may dramatically affect the buoyancy of rock masses and hence alter the driving forces for exhumation (Bousquet et al., 1997). The evolution of fluids or melts may create weak zones in the crust and enhance ductile or brittle deformation and shear zone development (e.g. Austrheim, 1998).

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2002

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