1. Erosion (glacial erosion)
Glacier has a strong erosion of power, most of the role of mechanical erosion, the erosion can be divided into the following categories:
(1) Stubbs erosion (plucking):
When the ice-bed at the bottom or the back cirque bedrock along the joints and loosening of repeated freezing and thawing, if these loose rocks and ice to freeze together, glacier movement when they pulled away rock, which is called out corrosion role. After pulling the post-glacial erosion of its steep curve of the valley is rugged to the formation of a trapezoidal profile of the slope curve.
(2) the role of abrasion (abrasion):
When the glacier movement, frozen in glaciers or ice at the bottom of rock debris, due to pressure from above glaciers of Glacier bed cut grinding and etching, known as the abrasive role. Abrasion role in the formation of bedrock with the polished surface, while or glaciation groove is a good evidence, and its direction can be used to indicate the direction of moving glaciers.
(3) the role of ice wedges (frost action):
Cracks in the rock contained in ice melt water, the role of repeated freezing and thawing, when the volume up when the reduction, caused by broken rock to become fragments, or from both sides of the slope to the glacier falling forward.
(4) Others:
When the ice-melting water into the river, its regular folder there are large volume of ice, will have a strong impact force to undermine cross-strait rock downstream.
Glacier Erosivity strength is subject to the following factors:
(1) ice thickness and weight. From thick and strong emphasis on erosion.
(2) the speed of moving ice. The speed of the larger erosion of power.
(3) to bring the number of stones. Carry more weight the more the number of persons, Erosivity stronger.
(4) of rough ground or smooth rock. Rough ground are more vulnerable to the erosion of glaciers.
(5) at the end of the nature of rock, soft rock at the end of those who are more vulnerable to erosion.
(6) of the tilt rock direction consistent with the direction of movement of glaciers, and prone to erosion.
Due to erosion caused by erosion landform are:
(1) cirque :
For the valley glacier, one of the important erosion landform, formed in the vicinity of the snow line, in flat or low-lying mountain snow Department up to, because of the repeated freezing and thawing snow, causing the collapse of the rock, in the gravity and the combined effect of snowmelt water, will rock eroded into-shaped or horseshoe-shaped depression, the typical cirque was formed. Cirque three steep rock face is to have a downhill openings, if the glaciers receded, the low-lying land with water into a lake, is Lake cirque.
(2) edged ridge , Kok Fung , ice dumb :
If cirque because digging erosion and the erosion of the role of Frost Crack continuous expansion of cirque wall retreat adjacent cirque ridge between formed gradually shaped blade, known as the ridge edge. The cirque of the convergence of several peaks, the shape is very sharp, then known as the peak angle. In between the lower edge of Saddle Ridge, the ice was dumb.
(3)spur , U-type Valley , stone depressions :
When the valley glacier from the highlands to the low mobility, spur was into a triangle, known as the spur. Glacier Valley because of the shape such as the U-shaped cross section, so called U-Valley. U-Valley Valley on both sides of a clear shoulder, shoulder valley below than straight, wide and flat at the bottom, if the bottom of the valley glaciers, glaciers dug by a solar eclipse, caused by the puddles down, then Stone called the low-lying land.
(4) Fjord :
At high latitudes, glaciers often into the ocean, in the shore erosion into some deep U-Valley, when the ice retreat, the water can enter very far along the valley, the original Valley then into ice fjord.
(5) hanging valley :
Hanging valley formed from the glaciers Erosivity differences, the main glaciers due to thick ice, the next eclipse strong, so deep U-Valley; and support of glaciers because of thin ice, the next eclipse weak, so U-Valley more shallow. Because in the glaciers and the main branch of the intersection of the glaciers often glaciers at the end of the disparity between high and low, when the teams entered the main glaciers of the ice when glaciers will fly into a waterfall-like fall, called hanging valley.
(6) sheep back stone :
For ice an erosion of the bed topography, is composed of bedrock hills, often groups of distribution, such as creeping Yuanwang sheep, the sheep known as the stone back. Their plane for Elliptic, the long axis of the flow direction consistent with the ice, glaciers upstream direction to a slope as a result of glacial erosion of the role of the lower slope, gentler slope, and there are many; while in the other side, by glaciers dug erosion, slope rough, steep slope more. Sheep back stone formation is the result of hard and soft rock is the order of white, when the erosion, the role of weathering, the soft rock will be eroded more deeply; while the hard rock resistance to erosion, weathering ability, Therefore, erosion, weathering, the hard rock than soft rock high, the formation of the elliptical uplift terrain, side by abrasion, corrosion side by digging.
(7) glacier polished surface, glaciers :
Sheep back in the stone or U-Valley and in the Great boulder on the role of glaciers often formed polished surface, when the glaciers moving objects is sand and silt, the rocks in the more dense, the polished surface is more for well-developed; if glaciers moving objects for gravel, then etched into the wall in the Valley Streak or groove called glaciers, one end of rough, the other side of thin, thick at one end point to the upper reaches.
2. Handling the role of (glacial transportation)
Because of the role of glacial erosion resulting from a large number of loose debris and a debris avalanche from the slopes, it will enter the glacier system, together with the movement of glaciers, which was carrying debris known as moraine material, according to their different locations within the glacier , removal can be divided into different types:(1) Table moraine: the exposed surface of the glacier moraine material.
(2) moraine : caught in the glacial moraine material inside
(3) at the end moraine : accumulation in the bottom of the glacier moraine material.
(4) lateral moraine : on both sides of the glacier moraine accumulation of objects.
(5) in the moraine : the convergence of two glaciers, its adjacent lateral moraine that is merged into one, joined at the middle known as the glaciers in the moraine.
(6) the end moraine (end moraine) : With the advance of glaciers, and in glaciers around the end of the moraine material, known as terminal moraine.
(7) back moraine : As the retreat of glaciers in the process, will brief stay local, and every stay will result in a retreat moraine.
(8) boulders : handling the role of glaciers, not only can moraine were moved to faraway places, but also can be a huge part of the rock moved to the high, which was handling the huge rock that is known as boulders, and its lithology and near the bedrock completely different.
Moving glaciers strong, but relatively, glaciers panning bad.
3. Stacking (glacial deposition)
Sand and gravel carried by glaciers often thrown out along the way it does in the glacier, the different forms of material handling, stacking it down the formation of the corresponding structures of various moraine. The so-called moraine material is directly caused by the glaciers of the ice layer is not sediments. Sediments and ice, that is directly deposited by the glaciers of the material, or as a result of the role of ice water sediments, and because of glaciation and deposition in rivers and lakes ocean substances.
Ice sediments can be divided into no sediment layer of ice and into a layer of ice between the two sediments:
(1) not a layer of ice sediments:
Such ice sediments from the time of the retreat of glaciers caused by gravel left behind, as the ice melted and left behind on the ground deposits of various sizes, with smaller stones at edges and corners, the surface to be polished or with a brush marks, not now after the accumulation of bedding, bedding such clutter-free ice sediments, often called ice boulders from the moraine soil were formed moraine terrain are:
a.) moraine hills :
Melting Ice, the original table with moraine moraine moraine in all sink to the bottom of glaciers, and the end moraine moraine as the base of these objects by the glacier moraine bottom topography, piled into a slope-shaped hills, known as ice moraine hills. Continental glacier area larger moraine hills, and valleys formed by glacial moraine hills, the scale should be smaller.
b.) lateral moraine embankment :
By lateral moraine and table in the retreat of glaciers Department moraine deposited by co-located on both sides of the valley glaciers, shaped into a breakwater to the upper reaches of the glacier could have been extended to near the snow line, and to the downstream and terminal moraine often linked embankment.
c.) the end moraine embankment :
End moraine embankment is reflected by the retreat of glaciers during the suspension period, if the glaciers melt in the supply and balance, then the end of the glacier might like to stop at a certain location, this time by the glacier moving to the material will be available on the flared end of the accumulation of ice into the embankment, known as the end moraine embankment. Continental glaciers smaller terminal moraine embankment height, length up to several hundred kilometers, the smaller arc curvature; the other hand, the end of the valley glacier moraine embankment height of up to several hundred meters, the length of the small curvature of the larger arc.
d.) Drum Hill :
Drum Hill is composed of ice sediments of a hill, about into an oval, long axis in line with the direction of flow, Ying is a steep ice, the ice back is a gentle slope, and its profile for the asymmetric convex. Drum Hill is generally believed that as a result of weakening the movement of glaciers, hampered by the end moraine deposited by. Its glaciers are mainly distributed in the mainland terminal moraine embankment within a few kilometers to several tens of kilometers, often occur in groups, resulting in drum; valley glaciers Hill small number of drums.
(2) into a layer of ice sediments:
This is the glaciers and ice-melting water from the common deposition results, the material carried by glaciers are melting the ice water after scouring and panning will be in accordance with the particle size, the accumulation of stratification, the formation of ice accretion, and in the glaciers from the brink ice deposits composed of a variety of landforms, known as ice accumulation landforms. There are several types:
a.) ice deposition , ice fan , outside the red plains :
At the end of the ice glaciers melt water carried by a large number of gravel, piled up in front of the glaciers in the valley or plain, on the formation of ice water deposition; if the ends of glaciers in the mainland, these sediments can be several kilometers long, in the end moraine piled into the outer breakwater fan, fan-called ice water; a number of ice water fan connected to the formation of the broad masses of ice water on the alluvial plain, also known as the plains outside the red. In these terrain, slope sediments were inclined to downstream to the lower reaches of particle size smaller.
b.) ice water lake , quarter-designate mud :
Lake ice is formed by ice melt water, because the retreat of glaciers, the moraine in front of the glaciers were to block access, can always be water lake. Lake ice has obvious seasonal variation, summer, more ice melt water, a large number of substances into the lakes, a number of coarse particles on the rapid deposition, but also fine particles suspended in the water, color, light; and the winter ice melt water reduction, a number of long-term suspension of fine particles of clay deposition began, the deeper the color. As a result, in the lakes caused by a rough on a small two-story is easy to identify sediment, called the quarter-designate mud.
c.) ice gravel port :
Port for ice gravel bedding and sorting through the fine sand formed, round or irregular shape of the hill. Ice gravel port usually has a layer of the upper layer moraine, ice boulders port is due to the small lake ice, river or stagnant glacier sediment point gap in the glacier bed in the end after the fall from the accumulation, with the drum Venturi difference in the shape of Yu Bing gravel port is not rules, and is layered into. In the mainland are glaciers and valley glacier ice boulders port development.
d.) port ice gravel terraces :
On both sides of the glacier, as the rock wall and lateral moraine endothermic more glaciers and ice on both sides than the middle to low, so ice-melt water on the pool in this, the formation of ice side of the river, and bring ice water substances, wait until the ice to melt, these substances accumulate in Glacier Valley on both sides of the formation of ice gravel terraces port, it developed in the valley glacier.
e.) pot hole :
Plain ice water often a circular depression, known as the pot hole. Its formation is due to depletion of glaciers, some residual ice was isolated and buried in ice water sediments, when melting ice caused by collapse, caused by pot hole.
f.) snake-like mound :
Snake Hill is a long and narrow twists and turns of the terrain, was snake-like bending,steep,narrower, and its extended broadly in line with the direction of the flow of glaciers consistent glaciers are mainly distributed in the mainland areas.
Snake-like dome of the main causes are:
1. Glacier, the ice along the glacier melt water infiltration fissure under the glacier, in the glacier at the bottom of the flow of the tunnel under the formation of ice when the ice completely melts, the tunnel in the gravel on the deposition and the formation of snake-like mound.
2. In the summer, an increase in ice melt water, ice sediments at the end of the formation of glacier ice water delta, wait until next summer, once again retreating glaciers, and then ice water to form a delta, and so constantly repeated, not even a cold water delta together, they form a serpentine-shaped mound moniliforme had.
Conclusion
Valley glacier landscape type is the most complex and diverse, can exceed more than 20 kinds. There are obvious vertical distribution. The above the snow line in the angle peaks and cirque ridge edge for heavy erosion landform; snow line until the embankment until the end moraine is U-shaped valley, lateral moraine embankment and moraine hills mainly erosion, geomorphology moraine , glacier terminal moraine embankment is finally represented moraine topography, the end moraine margin for fans and ice water outside the red plains of ice accumulation of landforms.
Continental glacier landscape type is relatively simple, only a dozen for the horizontal distribution. Moraine embankment to the end for the sector, in order to mainly moraine topography, development moraine hills and ice retreat end moraine embankment, outside the terminal moraine embankment to ice accumulation mainly geomorphic, development outside the red plains, deltas and ice water pot hole.
And above a glacier landforms ideal model. In fact glacier activities will be affected by climate, such as the valley glacier as an example, the oceanic climate glacier activity, and erosion of the more developed landforms; continental climate glacier activity weak, eroded terrain on the less developed.
