What is it: A mass of resistant rock with a smooth rounded stoss end and a jagged lee slope marked with striations.
Example: Nant Ffrancon Valley, Snowdonia
What processes are used?: Plucking and abrasion
How is it formed?
The pressure of the glacier over obstacles causes the ice to melt. As it pasts over the meltwater refreezes and plucking occurs. However, the main rock cannot be picketd up so the glacier continues to retreat over it. The stoss end has more abrasion and the lee slope has more plucking.
Striations are formed wjn large rocks under the ice scratch the bedrock and are found on the lee side.
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