Certain regions of Mars display scalloped-shaped depressions.
The depressions are believed to be the remains of an ice-rich mantle deposit.
 Scallops are created when ice sublimates from frozen soil.
This mantle material probably fell from the air as ice formed on dust when the climate was different due to changes in the tilt of the Mars pole.
The scallops are typically tens of meters deep and from a few hundred to a few thousand meters across.
 They can be almost circular or elongated.
 Some appear to have coalesced, thereby causing a large heavily pitted terrain to form.
 A study published in Icarus, found that the landforms of scalloped topography can be made by the subsurface loss of water ice by sublimation under current Martian climate conditions.
 Their model predicts similar shapes when the ground has large amounts of pure ice, up to many tens of meters in depth.

The process of producing the terrain may begin with sublimation from a crack because there are often polygon cracks where scallops form.
Certain regions of Mars display scalloped-shaped depressions. The depressions are believed to be the remains of an ice-rich mantle deposit.  Scallops are created when ice sublimates from frozen soil. This mantle material probably fell from the air as ice formed on dust when the climate was different due to changes in the tilt of the Mars pole. The scallops are typically tens of meters deep and from a few hundred to a few thousand meters across.  They can be almost circular or elongated.  Some appear to have coalesced, thereby causing a large heavily pitted terrain to form.  A study published in Icarus, found that the landforms of scalloped topography can be made by the subsurface loss of water ice by sublimation under current Martian climate conditions.  Their model predicts similar shapes when the ground has large amounts of pure ice, up to many tens of meters in depth.
The process of producing the terrain may begin with sublimation from a crack because there are often polygon cracks where scallops form.
Noachis quadrangle