Anorogenic plateau formation: The importance of density changes in the lithosphere - INSU - Institut national des sciences de l'Univers Accéder directement au contenu
Article Dans Une Revue Journal of Geophysical Research : Solid Earth Année : 2012

Anorogenic plateau formation: The importance of density changes in the lithosphere

Résumé

Away from active plate boundaries the relationships between spatiotemporal variations in density and geothermal gradient are important for understanding the evolution of topography in continental interiors. In this context the classic concept of the continental lithosphere as comprising three static layers of different densities (upper crust, lower crust, and upper mantle) is not adequate to assess long-term changes in topography and relief in regions associated with pronounced thermal anomalies in the mantle. We have therefore developed a one-dimensional model, which is based on thermodynamic equilibrium assemblage computations and deliberately excludes the effects of melting processes like intrusion or extrusions. Our model calculates the "metamorphic density" of rocks as a function of pressure, temperature, and chemical composition. It not only provides a useful tool for quantifying the influence of petrologic characteristics on density, but also allows the modeled "metamorphic" density to be adjusted to variable geothermal gradients and applied to different geodynamic environments. We have used this model to simulate a scenario in which the lithosphere-asthenosphere boundary is subjected to continuous heating over a long period of time (130 Ma), and demonstrate how an anorogenic plateau with an elevation of 1400 m can be formed solely as a result of heat transfer within the continental lithosphere. Our results show that, beside dynamic topography (of asthenospheric origin), density changes within the lithosphere have an important impact on the evolution of anorogenic plateaus.
Fichier principal
Vignette du fichier
PL02976.pdf (980.16 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

insu-00725599 , version 1 (28-02-2013)

Identifiants

Citer

Erik Duesterhoeft, Romain Bousquet, Henry Wichura, Roland Oberhänsli. Anorogenic plateau formation: The importance of density changes in the lithosphere. Journal of Geophysical Research : Solid Earth, 2012, 117, pp.B07204. ⟨10.1029/2011JB009007⟩. ⟨insu-00725599⟩
380 Consultations
767 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More