|
|
|
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
1 Biological & Geological Sciences, School of Engineering and Science, University of Paisley, Paisley PA1 2BE, UK
2 Laboratoire de Pétrologie, Géosciences Rennes, Université de Rennes I, 35042 Rennes Cedex, France
* E-mail: simon.cuthbert@paisley.ac.uk
| The first 20% of the full text of this article appears below. |
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). Hence there are important feedbacks between exhumation and metamorphic processes. The efficiency of metamorphic transformations (often controlled by the action of fluids as shown by Heinrich, 1982) controls the extent to which these feedbacks are effective, but also influences the preservation of the metamorphic record available to us.
This thematic set of papers comes from
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |