Inverted relief

Not to be confused with inversion or basin inversion in structural geology.
Inverted relief at former St. George Municipal Airport, Utah. The lava plateau upon which the airport was built once filled the bottom of a valley.
Inverted channels on Mars. These curved and crisscrossing ridges in the Aeolis region were once channels in a sediment fan. The channels were more resistant to wind erosion than the surrounding materials, so now they are left standing as ridges rather than valleys. Illumination is from the left.

Inverted relief, inverted topography, or topographic inversion refers to landscape features that have reversed their elevation relative to other features. It most often occurs when low areas of a landscape become filled with lava or sediment that hardens into material that is more resistant to erosion than the material that surrounds it. Differential erosion then removes the less resistant surrounding material, leaving behind the younger resistant material, which may then appear as a ridge where previously there was a valley. Terms such as "inverted valley" or "inverted channel" are used to describe such features.[1] Inverted relief has been observed on the surfaces of other planets as well as on Earth. For example, well-documented inverted topographies have been discovered on Mars.[2]

  1. ^ Pain, C.F., and C.D. Ollier, 1995, Inversion of relief - a component of landscape evolution. Geomorphology. 12(2):151-165.
  2. ^ Pain, C.F., J.D.A. Clarke, and M. Thomas, 2007, Inversion of relief on Mars. Icarus. 190(2):478–491.