Fretted terrain is a type of surface feature common to certain areas of Mars and was discovered in Mariner 9 images.
Fretted terrain in Arabia Terra (Ismenius Lacus quadrangle), seems to transition from narrow straight valleys to isolated mesas.
[14][15] Fretted terrain in Aeolis Mensae is similar to that of Arabia Terra, but it lacks debris aprons and lineated valley fill.
The Medusae Fossae Formation, a friable, layered material that is covered with yardangs surrounds parts of the fretted terrain in Aeolis Mensae.
[3] Research presented in 2018 at a Lunar and Planetary Science Conference in Texas suggested that the erosion that formed fretted terrain was aided by water moving under the surface.
Much of the area in high latitudes, especially the Ismenius Lacus quadrangle, is believed to still contain enormous amounts of water ice.
At times the tilt changes such that the polar ice caps sublimate and the atmosphere carries the moisture to the mid-latitudes where snow falls and accumulates.
[23][24] It would be difficult to take a hike on the fretted terrain because the surface is folded, pitted, and often covered with linear striations.
Around the many mesas and buttes in fretted terrain in Arabia is a feature called lobate debris apron (LDA).