glacial deposition

Question 1

terminal moraine formation

Answer 1

• terminal moraine is a ridge across the valley and made up of glacial deposits such as clay which is unsorted
• as the glacier moves downhill it acts like a bulldozer, pushing sediment in front of its snout as it goes
• when temperatures rise, the glacier melts, losing power and depositing the moraine

Question 2

esker formation

Answer 2

• eskers are meandering ridges along a valley floor formed by meltwater streams in/or underneath a glacier
• they are made up of meltwater sands and gravels. These are sorted by size because heavier stones are dropped first by flowing water
• the stones also tend to be more rounded than glacial deposits, because of the action of flowing water rounding the edges by erosion

Question 3

drumlin formation

Answer 3

• Drumlins are elongated hills of glacial deposits
• They are formed when the ice is still moving
• The steep ‘stoss’ slope faces upstream and the gently sloping ‘lee’ side indicates the direction in which the glacier was moving
• The drumlin would have been deposited when the glacier became overloaded with sediment and the glacier lost power
• The glacier may have experienced a reduction in power due to melting
• If there is a small obstacle on the ground, this may act as a trigger point and till will build up around it
• It may also have been reshaped by further ice movements after it was deposited