Graben

In geology, a graben (/ˈɡrɑːbən/) is a depressed block of the crust of a planet or moon, bordered by parallel normal faults.

[3] A graben is a valley with a distinct escarpment on each side caused by the displacement of a block of land downward.

Graben are produced from parallel normal faults, where the displacement of the hanging wall is downward, while that of the footwall is upward.

Comparatively little sediment enters the half-graben across the main bounding fault because of footwall uplift on the drainage systems.

The exception is at any major offset in the bounding fault, where a relay ramp may provide an important sediment input point.

Diagram illustrating the structural relationship between grabens and horsts
Infrared-enhanced satellite image of a graben in the Afar Depression
The Newark Basin , an early Mesozoic half-graben
Rima Ariadaeus on the Moon is thought to be a graben. The lack of erosion on the Moon makes its structure with two parallel faults and the sunken block in between particularly obvious.