Upland Glaciated areas Carboniferous Limestone areas Coasts

Three different types of area must be studied in the

lithosphere core –Click on the button of the landscape type you want to

revise.

Upland Glaciation Features

Features of Glacial Erosion

Features of Glacial Deposition

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Click on a feature of upland glaciation to find out more about it.Bac

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This is a Pyramidal Peak Pyramidal Peaks are the sharp

mountain tops formed when several corries cut back into the sides of a mountain. The steep backwalls of the corries create the near-vertical sides of the pyramidal peak. They are also called horns.

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This is a U-shaped Valley. U-shaped valleys are formed when ice from a corrie

moves slowly downhill under the influence of gravity, eroding and wearing away the rock by plucking and abrasion. Before glaciation the valley was V-shaped, as it was formed by the action of running water. The glacier changes the shape to a U-shape. U-shaped valleys are very long, straight, and deep. They are joined by tributary valleys, almost at right angles that are left high on the sides of the main valleys as hanging valleys. The interlocking spurs along the valley sides are left as truncated spurs, separating the hanging valleys. When a U-shaped valley reaches the sea it is flooded and creates a fjord (fiord).

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This is a Corrie. A corrie is a huge arm-chair shaped hollow in

the side of a mountain, there may be several of them around a mountain top, creating a pyramidal peak. Corries are formed when snow collects in the hollows on mountainsides and eventually turns to ice. The ice begins to move downhill under the influence of gravity. As it moves it grinds away at the land, eroding it by plucking and abrasion. Also as the ice moves in the hollow it rotates slightly and so digs out the hollow. Corries have a steep backwall and two steep sides, the fourth side is marked by a shallow lip that can sometimes hold back a corrie-lake or TARN. Pictur

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This is a Hanging Valley A hanging valley is created when a

tributary glacier joins a larger glacier. Because the two glaciers are different sizes the valleys they create are different depths. After the ice has melted, the two valleys are at different levels and the smaller of them is left well above the level of the other as a hanging valley. Rivers leaving hanging valleys may form waterfalls as they flow into the larger U-shaped valley.

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This is an Arete An arete is formed when two corries

on a mountain side cut away the rock and leave between them a high narrow ridge of rock (also known as a knife-edge ridge). Aretes run down mountain sides from Pyramidal peaks, separating U-shaped valleys and corries. They often come to an end at truncated spurs.

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This is Terminal Moraine Terminal moraine is formed when a glacier,

flowing down a U-shaped valley, pauses for a time and deposits large amounts of rubble and boulders just at the front of the ice. This build-up of waste material runs across the valley and forms a ridge, blocking the valley from side to side. Terminal moraine marks the limit of the ice movement. Terminal moraine is made up of mounds of unsorted stones and boulders that sometimes completely block the flow of river water down the valley and can hold back water in the form of ribbon lakes (so called because of their long, narrow shape).

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This is a group of DrumlinsDrumlins are formed under the moving sheet of ice as boulder clay is smeared across the land in small hillocks. These small hills are composed of an unsorted mixture of materials and have one steep face and one shallow face with the steep face pointing in the same direction as the movement of ice. Drumlins are usually found in clusters called ‘swarms’ to form what is sometimes called a “basket of eggs” landscape.

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This is an Esker

An esker is a long, narrow ridge of stones and gravel that marks the route taken by a river that flowed under the ice sheet. The material in the esker was deposited on the floor of a tunnel under the ice by the river and when the ice melted it was left behind as a twisting linear feature across the valley floor.

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This is a Roche Moutonnee A roche moutonnee is a large rock

protruding from the ground which was scraped and gouged by the passing ice during the last ice age. The side away from the direction of ice movement is often plucked and has a more vertical shape while the other end is more rounded.

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This is an area of Boulder Clay Boulder Clay is deposited

underneath the ice as it scrapes across the land. It is composed of unsorted material of all different sizes, from the smallest to the largest, hence its name.

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This is an Outwash Plain The outwash plain is formed in

front of the terminal moraine by the material washed out from under the ice by the melt water. It is mainly material that has been sorted by the action of the running water with the smallest particles travelling the furthest.

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This is a Kettle Lake When a glacier is retreating large

pieces of ice sometimes break off the snout and are left behind on the outwash plain. As these blocks slowly melt, the outwash plain is built up around them, raising the level of the ground. Once melted their position is marked by a depression in the surface (a kettle hole) that sometimes fills with water to create a kettle lake.

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Sketch of a Limestone Landscape

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This is a Limestone Pavement.

A limestone pavement is formed when a limestone layer is exposed to the effects of weathering by the removal of the overlying layers. Limestone is a very jointed rock, having horizontal bedding planes and vertical cracks caused by earth movements. The broken surface thus exposed to the acidic rain, formed by the absorption of atmospheric carbon dioxide by the moisture in the air, is dissolved and some of the rock is removed by solution. This makes the surface cracks wider and deeper (called grykes) and leaves between them raised blocks of limestone (called clints). Sometimes streams can flow onto the limestone and disappear down these vertical cracks – these are called swallow holes – and the streams continue to flow underground

through a complex of tunnels and caverns. Picture

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This is a Swallow Hole/Pot Hole.

Swallow holes are created when a stream disappears down a vertical crack in a limestone pavement. The swallow hole is connected to a system of underground tunnels and passages and sometimes caves and caverns. When there is no stream flowing into it it is called a pot hole or pot.

A kettle hole is formed when the land around a pot hole collapses and creates a depression around the pot hole.

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This is a Gorge Typically gorges are long and narrow with very

steep sides often containing a small misfit stream. They were once thought to be caused by the

collapse of the roof of an underground cavern but because of the lack of side tunnels and passages it is now thought that they were formed during the last Ice Age when the frozen ground didn’t let water flow through the limestone and rivers were forced to run across the surface. In time, deep, steep-sided valleys were eroded by these rivers and after the Ice Age, when the rivers once again disappeared underground, the valleys were left behind as gorges.

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This shows Impervious Cap Rock

This is the rock that lies on top of the layers of limestone and protects it from erosion (eg. Millstone Grit). Water can run across this rock, creating rivers that run down onto the limestone and quickly disappear underground into a swallow hole.

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This is a Disappearing Stream Where a river runs downhill from the

impervious cap rock onto limestone it will often run across the limestone for a short distance before meeting a vertical fissure (a swallow hole) and vanishing underground. The river will travel underground for some distance before appearing at the surface again at the foot of the limestone layer.

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This is Re-emergence/Resurgence

This is the point where a river that has been travelling underground through a series of limestone tunnels and caverns appears at the surface again, usually at the lowest level of the limestone layer.

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This is a Scar When a river erodes through rock to

create a valley for itself it sometimes exposes layers of limestone on the sides of the valley. These bare, exposed limestone surfaces are very obvious to see and are called “scars”. The block nature of the limestone is easily seen here and often piles of scree are found at the foot of the slopes. Usually scars are found in matched pairs on either side of the valley.

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This is a Stalactite A stalactite is formed when water

containing calcium carbonate reaches the roof of a cavern through a crack in the ceiling. When some of the water evaporates, a little of the calcium carbonate is left behind. Over time this process leads to the formation of a long icicle-shaped structure called a stalactite hanging from the roof of the cave. Pictur

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This is a Stalagmite When water containing calcium

carbonate drips from the roof of a cave it hits the floor and splashes outwards. Some of the calcium carbonate is deposited creating a stalagmite, that is much wider than a stalactite.

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This is a Pillar When a stalactite and a

stalagmite grow enough they may actually meet, to form a pillar.

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This is a Tunnel Tunnels are created in

limestone when the cracks and fissures found in the limestone are enlarged by the solution of rock by acidic rainwater as it finds its way through the permeable limestone.

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This is a Cave or Cavern Caves and caverns are created

in limestone as acidic rainwater travels through the limestone. Tunnels may be enlarged and roof collapses help to raise the roof height. Much of this work is done during and after storms when the water levels in the system are higher than normal.

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This is Scree Scree is not a limestone feature.

It is simply piles of rock broken off from the face of the scar above and occurs on any type of rock and landscape.

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Sketch of a Coastal Landscape

Click on a feature to find out more about it.

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This is a Cliff A Cliff is formed by the action of

waves as they batter against the cliff, particularly during storms. The pounding action of the waves wears away the rock at the foot of the cliff cutting a notch in the rock and possibly creating caves in areas of weakness. As this notch gets deeper the cliff above is undercut and will eventually collapse into the sea – the cliff retreats. Pictur

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This is an Arch An arch forms when caves on

either side of a headland meet in the middle to form a tunnel. This tunnel is gradually enlarged and widened into an arch. The erosion continues, making the arch higher and wider until the top eventually collapses leaving a stack standing some distance from the cliff.

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This is a Stack/Needle A stack is the remains of a former

arch that has collapsed into the sea. The stack itself is eroded and may eventually become a needle. As erosion continues at the foot of the stack, the base gets so narrow that the stack collapses leaving a stump. The stump becomes part of the wave-cut platform.

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This is a Wave-cut Platform This is the area of relatively

level rock area left behind as the cliff retreats due to the undercutting by the waves. Often this platform is covered by sand creating a beach.

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This is a Cave A cave forms at the foot of a cliff

when the waves pick out an area of weakness in the rock of the cliff (ie. a crack or fracture) and slowly widen and deepen it. Caves are usually above the level of the sea and are dry except at high tide. Sometimes a cave leads upwards to the surface of the headland creating a blowhole, where the sea can push through as a waterspout.

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This is a Headland A headland is a promontory of

rock that protrudes out into the sea, with water on three sides. The area is exposed to a lot of sea erosion on three sides and over time is gradually eroded and can even be removed. Between headlands, sandy areas called bays are found, containing beaches.

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This is a Blowhole Sometimes when a cave is being

eroded by the action of waves, the cave turns upwards and emerges on top of the headland as a blowhole. During storms large waves may force their way through the cave and create fountains of water from the blowhole.

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This is Cliff Slumping Large sections of a cliff

sometimes “slump” from their original position, in a rotational motion. This can be caused by heavy rainfall lubricating the soil and rock making it easier to move.

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This is a Rock Fissure This is simply a crack in the

rock that allows the elements of weathering access to the interior of the rock. It is a weakness in the rock that is rapidly picked out by erosion and enlarged.

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This is a Pyramidal Peak

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U-Shaped Valley, Alberta

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Corrie, Newfoundland

The corrie has three steep sides and a low lip on the fourth, It is surrounded by aretes and the lip may hold back water to form a Tarn or corrie-lake.

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A Hanging Valley, Newfoundland

Hanging valley

Side of main U-shaped valley

Break of slope between main valley and hanging valley

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Aretes leading to a Pyramidal Peak

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Two Terminal Moraines in a U- Shaped Valley

Terminal Moraine

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An Esker

Man standing on esker ridge

Winding Esker ridge

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Roche Moutonnee, Ontario

Side view showing smooth side towards ice and plucked side formed as ice moved away from rock.

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Outwash Plain

Outwash plain showing braiding of rivers.

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Boulder Clay surface, Canada

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A Drumlin

Side view of drumlinshowing asymmetricalshape

Direction of ice movementBac

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A Kettle Hole/Lake

The hollow now occupied by the lake was once the location of a huge piece of ice left behind by the retreating glacier.

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Limestone Pavement

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Swallow Hole – Gaping Gill, England

Over the swallow hole is a winch used to lower tourists into the depths (105m).

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Gorges, England

Cheddar Gorge, England Gordale Scar, EnglandBack

Impervious Rock Cap

Impervious Rock Cap

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Disappearing Stream

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Re-emergence (Resurgence)

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Re-emergence of Malham Beck from the bottom of the limestone layers of Malham Cove.

The site of re-emergence at Malham Cove although the stream cannot be seen here.

Great Close Scar, Malham

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Stalactites

Stalactites in Oxford Pot, England

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Stalagmites

Stalactites and stalagmites in Oxford Pot, England.

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A Pillar

A nearly complete pillar (on the right) in Oxford Pot, England

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A Cave with stalactites

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A Tunnel (Oxford Pot, England)

The man has a collapsible ladder in his left hand.

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Cliffs (Moher, Ireland)

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Sea Arch (The Needle, Caithness)

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Sea Stacks/Needles, Nova Scotia

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Wave-cut Platform and Needle

Wave-cut Platform

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Sea Cave

Small cave

Possible cave

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Headland (erosion features

labelled)

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Blowhole

Hawaii

Enlarged Blowhole, New Zealand

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Slumping (Naish, England)

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Rock Fissure

A stack (The Old Man of Hoy, Orkney) showing many rock fissures

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