Glaciation in the Dublin/Wicklow Mountains
The Dublin/Wicklow mountains display some fantastic features of the two ice ages Ireland experienced millions of years ago. Glendalough is famous for the two large lakes which have formed from the melt water of glaciers left in the U-shaped valleys.
U-Shaped Valleys
These U-shaped valleys have large steep sides which have been eroded by the glacier. The valley would have once been a V-shaped valley associated with fluvial erosion processes but the power of the moving glacier along with processes of weathering and erosion would have transformed the valley in to a U-shaped valley. Freeze-thaw action would be occurring as well as plucking and abrasion. Plucking is a process whereby the ice of the glacier plucks debris from the floor. Abrasion involves the debris within the glacier smoothing and polishing the floor of the valley.
U-Shaped Valleys
These U-shaped valleys have large steep sides which have been eroded by the glacier. The valley would have once been a V-shaped valley associated with fluvial erosion processes but the power of the moving glacier along with processes of weathering and erosion would have transformed the valley in to a U-shaped valley. Freeze-thaw action would be occurring as well as plucking and abrasion. Plucking is a process whereby the ice of the glacier plucks debris from the floor. Abrasion involves the debris within the glacier smoothing and polishing the floor of the valley.