2. Glacial
Troughs
DEFINITION
A valley shaped by valley glaciers and ice streams within ice sheets that
has a distinct trough form. The trough head is enclosed by glacial cliffs
and may be overlooked by extensive snow-gathering areas.
• Glacial troughs are also known as U shaped valleys.
• Within a glacial trough you can also find hanging valleys and
waterfalls, truncated spurs, misfit streams, ribbon lakes, rock steps and
basins.
• The main processes involved in the formation of glacial troughs are
abrasion and plucking.
4. HOW THEY ARE FORMED?
During the glacial period these valley would have been filled with
glaciers, like a river of ice. As the glacier moved down the valley it
plucked the rock from beneath and then the rocks then rub against the
bed of the valley, eroding it further. This deepens and widens the valley.
At the front end of the glacier it acts like a bulldozer, shifting and
removing soil, plucking rock from interlocking spurs and truncating
them.
5. TERMINAL MORRAINE
Definition
A terminal moraine, also called end moraine, is a moraine that forms at
the snout of a glacier, marking its maximum advance. An end moraine,
in contrast, is at the present boundary of the glacier.
• One famous terminal moraine is the Giant's Wall in Norway which,
according to legend, was built by giants to keep intruders out of their
realm.
6.
7. HOW THEY ARE FORMED?
When glacial ice melts, different types of rock are laid down that have
been carried along by the glacier. Piles of these deposits are called
moraines.
