Landforms produced by glacial deposition

Till deposits are unsorted mixtures of rocks, clays and sands. Individual stones are subangular, not round like river or beach materials. The composition of till reflects the character of the rocks which it has passed , for instance East Anglia is covered by chalky till because the ice passed over a chalk escarpment - East Anglian Heights.


Erratics


Erratics are boulders picked up and carried by ice often for many kilometres. Examining the rock for its origins, helps to track ice movement, for instance volcanic material from Ailsa Craig in the Firth of Clyde has been found 250km to the south, on the Lancashire plain.

                                                 Glacial erratic near Point Lake, Canada


Moraine


A moraine is type of landform that develops when the debris carried by a glacier is deposited. There are various types of moraines that are formed:


Lateral moraine


This feature is formed from debris, derived from frost shattering of valley sides and carried along the edges of a glacier. When the glacier melts, it leaves an embankment of material along the valley sides as shown below.

                                                           Lake Hoare, Canada


Medial moraine


This form of moraine is found at the centre of a valley and is a result of two merging lateral moraines, where two glaciers joined.

                                                     St. Elias Mountains, Canada


Terminal moraine


A terminal moraine is high mound of material extending across a valley or lowland area. They are at right angles angles to and are marking the maximum advance of the glacier or ice sheet.

                                                           Bylot Island, Canada


Recessional moraine


This moraine marks the interruptions in the retreat of ice when the glacier or ice sheet remained stationary long enough for a mound of material to build up.

                                                      Thompson Glacier, Canadian Arctic


Push moraines


If the climate deteriorates sufficiently for the ice temporarily to advance again, previously deposited moraine be shunted up into a mound. This is recognised by individuals stones which have been pushed upwards from the original horizontal position.

                                                The Mer De Glace, Chamonix, French Alp
Drumlins

These are smooth, elongated mounds of till with their long axis parallel to the direction of ice movement. The steep stoss end faces the direction from which the ice came, while the lee side has a more gently streamline area. There is often disagreement about the formation of drumlins, I won't go into detail this but the most accepted explanation is that ice became overloaded with material, reducing the capacity of the ice, material is then deposited. It then may be moulded and streamlined later by ice movement.

                                                       Morley flats, Calgary, Canada