Fold and thrust belt

A fold and thrust belt (FTB) is a series of mountainous foothills adjacent to an orogenic belt, which forms due to contractional tectonics.

Fold and thrust belts commonly form in the forelands adjacent to major orogens as deformation propagates outwards.

This sequential propagation of thrusts into the foreland is the most common.

In map view, fold and thrust belts are generally sinuous rather than completely linear.

[1] Where the thrust front bulges out in the direction of tectonic transport, a salient is formed.

Modelling of a fold and thrust belt in a sand box
Profile through the Pyrenees. In the south a fold and thrust belt exists as sediments are folded and stacked (thrust) on top of the other.
An example of thin-skinned thrusting in Montana . The white Madison Limestone is repeated, with one example in the foreground (that pinches out with distance) and another to the upper right corner and top of the picture.