31. Glacial erosion has left a rugged landscape, which close of the volcano is smoothed by deposits coming from the volcano.32. The loch occupies a basin produced by the overdeepening of the valley by glacial erosion , along an east-west fault line. 33. During the Ice Age glacial erosion eroded one side of the valley resulting in the steep valley which is seen today. 34. During the Quaternary Period the area experienced many glacial periods and retreats and such evidence for the glacial erosion of Mt. 35. The process of nivation follows, whereby a hollow in a slope may be enlarged by ice segregation weathering and glacial erosion . 36. The depression, along with the parallel one, now occupied by the Cowgate, was formed by glacial erosion during the Castle Rock. 37. Prior to Late Pleistocene glacial erosion these centers formed a series of coalesced, low-profile shield volcanoes of unknown volume and distribution. 38. Lassen Peak's shape was significantly altered by glacial erosion from 25, 000 to 18, 000 years ago during the Wisconsin glaciation. 39. Less than two billion years ago and before glacial erosion , these beautiful quartzite and granite mountains were as high as the Rockies. 40. Subsequent glacial erosion was resisted more by the dolerite, which protected the softer rock to the east, leaving a crag and tail formation.
