Influence on slope shape:
Planar slope failure (rare but occurs in well-bedded rocks like sandstone):
- Mass movement along a slip plane where bedding planes are parallel to the angle of the slope.
A large section of slope (i.e. the block) moves downward in a block leaving behind a slip plane which is a large area of under soil exposed by the moving block called a scar. The block forms a mound lower down the slope. The slope is more gentle sloping.
A scar = a slip plane left behind by the downward movement of a block in which a large area of under soil is exposed by the moving block
A large section of the slope slides & moves backwards at the same time causing a backward tilting block which forms a feature called a terrace. With several rotational slumps in a row there will be a sequence of terraces called steps. The area exposed by the slump is called a scar. The slope is more gentle sloping.
Comments
No comments have yet been made