Chatter Marks - Marks caused when rocks stuck in the base of the ice have removed thin flakes or chips from the bedrock surface.
P-Forms: These features, which extend several to tens of metres in length, are of uncertain origin. P-forms (P for ) are smooth-walled, linear depressions which may be straight, curved, or sometimes hairpin-shaped and measure tens of centimetres to metres in width and depth. Their cross sections are often semicircular to parabolic, and their walls are commonly striated.
MESO-SCALE:
Whalebacks: Rock drumlins and streamlined spurs; these are smoothed areas of bedrock, attributed to unconfined glacier slip across the bedrock surface. They have a characteristic domed shape, and their long axes tend to be aligned parallel to ice flown direction.
Roche Moutonnee: are outcrops of resistant bed rock with a gentle abraded slope on what would have been the upstream side of the ice (stoss slope) and a steep rougher slope on the downstream side (lee slope). The name is French and translates into English as 'sheep rocks', a good description of them when seen from a distance. The smooth upstream slope is probably caused by abrasion as the ice advances over the rock, and the rough 'tail' is due to the action of plucking where ice has attached to the rock and literally pulled rock fragments away. Plucking could occur because as the ice moved up the stoss slope there was a reduction in pressure, allowing liquid water to re-freeze and attach the ice to the underlying rocks.
Glacial Grooves: Grooves are common on recently exposed bedrock, and on stones that have been transported by glaciers. These have classically been used to infer ice flow direction over bedrock, but as some of the examples illustrate, this can be misleading
Rock Basins: The floor of a glacial trough is uneven. It usually consists of a series of depressions or rock basins – with a reverse gradient at the lower end, separated from the next by a rock bar or step. The formation of such basins is not fully understood, but two theories seem likely: They correspond to areas of the valley floor where the bedrock was weak and thus more easily eroded. Or they correspond to areas where erosion by the glacier increased due to the sudden addition of ice possibly from a tributary glacier.
Subglacial meltwater: When subglacial meltwater drains through tunnels, it defines stream systems similar to surface streams. Those subglacial streams may deposit sediment just as a surface stream would, but confined to the tunnel. The result is a ridge of gravel termed an esker, often sinuous (snake-like), which wanders across a formerly glaciated region. The gravel in an esker may have been transported and even eroded by the glacier, but the subglacial stream sorts the fine material out and carries it away. Thus, eskers are well-drained and make great (if winding) roadbeds. They are commonly mined for their gravel
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Channels: Provide the systems by which water is channelled away from the glaciers, and are often scoured out by extremely powerful water. On a large scale, these are visible on satellite images as vast anastomosing channel features far larger than current drainage networks.
MACRO-SCALE:
: are produced at the heads of valley glaciers, and are formed through a combination of glacial erosion at the cirque base, and frost shattering of the cirque headwall. These are the locations of initial glacier growth, often in the shelter of high mountain masses, and are a classic feature of alpine glacial environments. Whilst Cirque is the standard term for this type of feature, in the UK you may often come across local terms (Cwm in Wales, Corrie or Coire in Scotland) if you travel about.
Arêtes:
Cols: passage or gap formed by back-to-back erosion of cirques
Pyramidal Peaks:
Glacial Troughs: Glacial troughs; formed by valley or outlet glaciers confined by the topography are dramatic valleys with often a (NOT 'U' shaped!) formed by erosion of a confined glacier mass, usually as it moves down former river valleys. It is not known whether similar features are produced beneath major ice streams, although it is likely to be the case. As with many other large glacial erosion features, glacial troughs develop during multiple stages of glaciations over geological time, and do not reflect one simple event.
Hanging Valleys: Hanging valleys are often associated with , joining the main valley along its sides. They are the product of different rates of erosion between the main valley and the valleys that enter it along its sides. The floors of the tributary valleys are eroded and deepened at a slower rate than the floor of the main valley, so the difference between the depths of the two valleys steadily increases over time. The tributaries are left high above the main valley, hanging on the edges, their rivers and streams entering the main valley by either a series of small waterfalls or a single impressive fall.
Truncated Spurs: Spurs that projecting into the original river valley are cut short, their lower ends being destroyed by the moving ice. They may be cut back right to the edges of the new valley, or still project slightly into the valley. This shortens the spurs, or truncates them. They are then known as Truncated Spurs
Areal Scour: The most extensive, but unspectacular, erosional landscape left behind by a continental ice sheet is that of "areal scour". The landscape spreads out for miles with little relief on either erosional or depositional topographic features. Local depressions may be scour features in weak or jointed rock, or small kettles. This picture from the Canadian Shield is typical of the areal scour left by large ice sheets.
Crag and tail: A crag and tail is a larger rock mass than a Roche moutonnee. Like a Roche moutonnee, it is formed from a section of rock that was more resistant than its surroundings. On the lee side of the resistant rock, the bed rock was protected from the erosional power of the glacier.