Erosional Landforms 3

Geography: Edexcel A Level, topic 2.4.4

Small Glacial Landforms

A range of glacial erosional processes have created a variety of distinctive small landforms in many upland glaciated areas around the world.

Roches moutonnees are isolated rocks, generally between 5 to 30m in height, along the base of a glaciated valley.
They are characteristically smooth on one side and jagged on another.
They form where a glacier moves over a band of harder rock and it smoothes the upstream side by abrasion often leaving striations to show the direction of movement.
As the glacier spills over the top of the obstruction it removes the loose rocks by plucking, leaving a jagged edge on the downstream side.

These are Scottish names for an irregular landscape of small, bare, ice-sculpted hills (knocks) and small lakes (lochans).
They are the result of widespread abrasion and plucking by an ice sheet moving across an extensive area of hard metamorphic rock (gneiss).
Erosion of faults and joints has created the lochan from softer rocks and knocks leftover from the more resistant rocks.
Differential geology, therefore, plays a key role.

Crag and tails are created by differential geology.
A resistant rock forms an outstanding feature as it doesn't get eroded as much as surrounding rock. This is the crag.
Deposition of eroded material in the lee of the crag creates the tail.
Edinburgh Castle and the Royal Mile down its tail is an excellent example of this feature.

Knocks and lochans are the result of widespread abrasion and plucking by an ice sheet moving across what kind of rock?
Which of these are NOT glacial erosional landforms?