diagram of an escarpment.

An escarpment is a landscape formed by differential erosion. Differential Erosion means lower or higher erosion of different rocks depending on their resistance. In sediments, there are always harder and softer layers, so weathering of this rock will always produce escarpments. The hard rocks form cliffs, as the softer layers below are eroded faster, undermining the hard rocks above. So the hard rock is breaking down, forming sharp edges, instead of being rounded by erosion.

If the layers are horizontal, the result is called a cliff. If they are sloping with a dip less than 30°, the result is called escarpent or cuesta, an asymmetric ridge with a steep side across the layer and a shallow side on the top of the layer, sloping with the dip of the layer itself.