28 September 2006
This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows
layers exposed in the north polar region of Mars. The north polar cap is
underlain by a thick sequence of layered material. The layers are most
commonly exposed on the slopes of troughs that are believed to have formed
by wind erosion. The layers give a banded appearance. In this example,
some of the layers are cut off (truncated) by other layers. This
truncation is a classic, textbook example of an erosional unconformity, a
term commonly used by geologists. The unconformity occurs when deposition
of new layered material stops for a while, and erosion occurs. Then, new
layers form on top of the eroded surface and the older layers, at some
point in time when the erosion stops and deposition of layered material
resumes.
Location near: 78.6°N, 342.0°W
Image width: ~3 km (~1.9 mi)
Illumination from: lower right
Season: Northern Spring
