Erosion and tectonics

The interplay between erosion and tectonics has been a matter of debate since the early 1990s. While tectonic effects on surface processes such as erosion (for example, the river entrainment subsequent to a tectonic rock uplift) have been long recognized, the reverse (the effects of erosion on tectonic deformation) has only recently been addressed thanks to the availability of computer modelling techniques.

Tectonics modify erosion because it modifies the surface topography, which is the most important parameter controlling surface processes of mass transport. Erosion might be reduced on a flat landscape before a normal fault generates a topographic gradient for example. Landforms are generally considered as the result of the interaction between the tectonic and isostatic uplift and the response of surface erosion.

The way the tectonic deformation is influenced by erosion is more subtle and is produced by the weight of the mass removed (eroded) from the surface and the weight of the deposited sediments, which in some circumstances can become relevant enough as to modify the state of stress at depth and the pattern of tectonic deformation.

Although originally proposed for continental collision settings, presently the effects of erosion on tectonic deformation have been extended to a diversity of tectonic settings including continental margins, plate subduction, and high plateaus.