Paper 2: The UK's Physical Landscape - Topic 4 Flashcards
How has Geology shaped Physical Landascape in Malham Cove?
The Malham Cove (in the Yorkshire Pennines) is made up of crushed shells of coral that lived in the seas 300 million years ago. This means these rocks are made up of limestone. Limestone is made as coral and fish die, with their skeletons falling to the sea floor, with the weight compacting this into rocks, while calcium carbonate (in rocks) cements them together. Sand was then laid on top of this, to make these layers called strata. These rocks 300 million years ago were under the sea, but due to tectonic plate movements, along with the movements of land masses to form the world we know today, with the UK no longer over a plate boundary, and now far further above sea level, meaning it is no longer a volcanic island.
How has Geology shaped the UK
- 250-350 million years ago, the UK was under a warm tropical sea
- As tropical fish died, their skeletons were crushed and compressed together forming limestone (sedimentary rock)
- Other rocks like sand and mud were laid down in layrs or strata on top of this
- Some rock is resistant, some is less so
- Other rock strata were deposited on top of limestone e.g Sandstone and Shale, which is weaker than sedimentary rock
How has Tectonics shaped the UK
- 500 million years ago the UK was where Antarctica was and has slowly moved north.
- The England and Wales + Scotland and Ireland collided to form huge volcanoes erupting massivly, with mountains being formed
- These volcanoes formed huge eruptions and amounts of lava coming out, alongside tall mountains
- Over 300 million years, the plate the UK sits on shifted away from the tropics, while convection currents under the plate have uplifted the land from below the sea, making it new land
- During the uplift, some rocks snapped and moved along faults in a series of earthquakes over thousands of years. Each movement disturbed the strata so that they tilted
- Sometimes, the faults form a steep edge (fault scarp) where uplift has raised some points more than others
Hoe has Galciation shaped the UK
-As the Pennines were uplifted, rivers like the Wharfe eroded into them, creating V shaped valleys. But the most recent Ice Age (over 10,000 years ago), brought huge glaciers to the Pennines.
They had 2 effects:
- Altering river vallies, making them deeper and widening them into U-shape troughs
- As they melted, the glaciers left features like Malham Cove with a spectacular waterfall
How has Geology, Tectonics and Galciation created Upland Areas
Geology, Tectonics and Glaciation over thousands of years have created upland lanspdscapes. Geology has resulted in the UK being made up of various rock types, including sedimentary, igneous and metamorphic rock, meaning rocks will be of different strength and get eroded easier (in this case there is a lot of limestone). Tectonic Processes means that this land has been uplifted and moved north up to a point that this is raised up high enough in a cold enough area to mean that glaciation can tske place, meaning glaciers can shape the landscape and rock in this way in order to make peaks and valleys, along with U-shaped valleys and V-shaped valleys.
What are Igneous Rocks? (+Example)
Igneous rocks are created by volcanic activity when magma/lava cools, forming rocks made of crystals that are usually hard. Granite is an example of igneous rock.
What are Sedimentary Rocks? (+Example)
Layers if Sediments are compacted together until they become solid rock, and are deposited in layers, or form the remains of plants and animals on somewhere like a sea bed/floor. An example of Sedimentary Rock is Limestone or Chalk.
What are Metamorphic Rocks?(+Examples)
Metamorphic Rock is formed when other rocks are changed due to extreme presure and heat. They are usually comprised of layers/bands of crystals and are very hard. For exmple, shale becomes slate and furthr pressure and heat make slate become schist.
*Formation, Characteristics and Resistance of Chalk
- Formed from softer, younger sedimentary rock which is less resistant to erosion
- Very prous. Medium resistance but stronger than clays as well as younger sands
*Formation, Characteristics and Resistance of Limestone
- Permeable with underground rivers, passages and caves
- It is sedimentary rock, which was made up of crushed and compacted dead fish and coral which turned into strata
*Formation, Characteristics and Resistance of Clay
- Formed from muds deposited by rivers at sea
- It is soft and crumbly. When compacted, it become shale, while it is also generally weak
*Formation, Characteristics and Resistance of Granite
- Formed by magma cooling deep underground and is an igneous rock
- Contains crystals of quartz (glassy), feldspur (white) and mica (shiny black), giving it the look it has.
- Very resistant
*Formation, Characteristics and Resistance of Schist
- It is formed by even further metamorphis of slate, where it is partly melted and solidified also
- This means that schist is very resistant
*Formation, Characteristics and Resistance of Slates
- Slate is formed from either heated muds or shales
- It is a very resistant rock as a result of this
- After further metamorphis, it can become schist
Upland:
- Location in the UK
- Regions/National Parks
- Rock Types (Ing/Sed/Met)
- Rock Examples
- Approx. Age
- Resistance: More/Less
- Relief - Steeper/Flatter
- Features
Location in the UK:
West and North of the UK (to the left of the Tees-Ex line)
Regions/National Parks:
North West Highlands, Grampian Mountains, The Pennines, Brecon Beacons
Rock Types (Ing/Sed/Met): The upland side consists of more Igneous and Metamorphic Rock
Rock Examples:
Slates and Shales + Old Red Sandstone + Carboniferous Limestone + Millstone Grit + Schist + Gneiss, Quartzite + Basalt, Granite
Approx. Age:
Average Age = 425 Million Years Old
Resistance: More/Less:
There is more resistance in Upland rock, because it is more metamorphic and igneous, making it stronger
Relief - Steeper/Flatter:
Upland relief is steeper than lowland, with the elvation ranging from around 200m-500m above sea level
Features:
Overall, Upland rock is stronger, older, and also steeper than lowland rock
Lowland:
- Location in the UK
- Regions/National Parks
- Rock Types (Ing/Sed/Met)
- Rock Examples
- Approx. Age
- Resistance - More/Less
- Relief: Steeper/Flatter
- Features
Location in the UK:
South and South-East of England (to the right of the Tees-Ex line)
Regions/National Parks:
South Downs, North Downs, Chiltrn Hills, Salisbury Plain, Cotswold Hills
Rock Types (Ing/Sed/Met): The lowland side mostly consists of more sedimentary rock
Rock Examples:
Clays, Sands, Sandstones + Oolitic Limestone + Chalk + Sands and Clays + Alluvium
Approx. Age:
Average Age = 116 Million Years Old
Resistance: More/Less:
There is less resistance in Lowland rock, because it is just Sedimentary Rock, which is weaker than the other rock types like Metamorphic and Igneous, which are stronger
Relief - Steeper/Flatter:
Lowland relief is flatter than Upland relief, with the elevation usually going no higher than 200m above sea level
Features:
Overall, Lowland rock is weaker, younger and also flatter than upland rock
Lake District: Location
- Found in North-West of England
- Scaffel Pike is the highest point in the Lake District (978m above sea level)
- Scaffel Pike is England’s highest Mountain
Lake District: Geology
Igneous basalt rock from surface eruptions at Borrowdale and granite igneous eruptions below the surface at Eskdale. These are both resistant. There is sedimentary rock present too when the UK was under tropical seas (350-250mill) such as mud and sandstone.
Lake District: Tectonic Processes
Large volcanoes 450-300 million years ago erupted in the Lake District in areas such as Borrowdale caused mountain building and the mountains we see today.
Lake District: Effect Of Ice Age
Some things created 12,000 years ago when the uplands were under 300m of ice which included corries, V-shaped valleys and U-shaped valleys, just to name a few. The glacial processes also left steep sides, flat bottoms and hanging valleys.
Lake District: Shape of Landscape and Formation
Corries: They are shaped a hollowed out armchair formation, with steep back walls, and a lower front
U-Shaped Valley: They have steep sides, flat bottoms, as well as hanging valleys
Some rocks are left jagged, while other rocks have fallen off as smaller rocks and as scree
Lake District: Weathering Processes
Some of the weather processes are:
- Freeze Thaw
- Slope Processes
- Rockfall/Landslides
- Post Glacial River Processes (created misfit streams)
Freeze-Thaw happens when water seeps into cracks and freeze, which pushes the rock apart before it then melts and freeze again to make the cracks bigger.
Lake District: Slope Processes
Slope Processes includes more mass movement, e.g rockfalls, slides, slumps and soil creep. Landslides are common in upland areas. The Lake District region is the UK’s wettest (over 2000mm of rain per year), and this rain will saturate the rocks and increase the weight of the rocks, meaning it will fall to leave behind jagged rocks.
Lake District: Post-Glacial River Processes
Glaciers created deep U-shaped valleys and hollows filled nowadays by lakes. Today, rivers flow in the valley bottom instead of glaciers. These rivers are samll comoared to their valleys and are known as misfits. They deposit silt and mud (known as alluvium) in the valley bottoms making them fertile for farming.
Lake District: Climatological
These landscapes attract a lot of relief rainfall, because hillsides will create this relief rainfall. Also, higher areas of land will be colder and wetter (every 100m up is -1°C on average), which is why it will be colder and wetter too.
Weald: Location
- The lowland is found in the South-East of England, especially the Weald
- The lowland feature is including of the South and North Downs and the Weald
- Highest point is Crowborough Beacon which is 225m above sea level
Weald: Geology
The Downs and the Weald are lowland landscapes. They are chalk escarpments that lie either side of a large, flat area of clay. The valley is flat (with some small hills). Glacial meltwater eroded large amounst of sedmentary rock leaving this dostinctive lowland landscape.
Weald: Tectonic Processes
There are lots of layers of sedimentary rocks, which have been moved by uplift. The top parts of sedimentary rock have been eroded away to create ‘The Weald’. The Weald gies from the South Downs, all they way up to the North Downs. Tne alluvium will in future compact to become sedimentary rock.
Weald: Effect of Ice Age
During glacial periods, (when the climate was colder) the gaps in the chalk froze making it impermeable. When seasonal snow melt occured, it couldn’t inflitrate into the chalk and indtead ran over the top and eroded valleys. Now, water runs underground through the chalk and the rivers cannot be seen.
Weald: Shape and Landscape Formation
Dry valleys are found in UK lowland landscapes, which hve no visible streams. They have been formed during glacial when the cooler climate led to more freeze-thaw weathering and glacial snow melt, meaning that streams had more water in them than they have today.
The hills are gently sloping and are not as steep and as harsh as the ones found in upland areas.
Weald: Weather Processes
The two types of weather process have taken place to erode the rocks in this area: Biological Weathering, and Chemical Weathering.
- Plants and Animals break down the structure od the rock over time as they burrow into rock, which forms cracks in the rock
- Rainwater absorbs CO2 as a by-product of pollution, meaning the rain/surface water becomes a weak carbonic acid. The acid reacts with calcium carbonate in the Limestone and Chalk, dissolving the rocks
Weald: Slope Processes
Soil Creep is the slowest of all mass movements. It takes place at a rate of 1-3mm per year in temperate latitudes and 10mm per year in tropical forests. Soil such as sandstone and clay absorb large amounts of moisture and become saturated - they can move down the slope.
Weald: Post-Glacial River Processes
The UK climate is very wet. Heavy rain can lead to flooding, so when rivers flood the overflowing water carries sediment and deposits silt on the valley floor forming a floodplain. This floodplain is very fertile, which is important in lowland areas, hoever in upland areas tne river is eroding downwards, carving out a V-shaped valley.
Weald: Climatological
This landscape will not attract as much relief rainfall, as the hills are not as steep and tall as the mountains that are found in the Lake District. One the note of rain, these areas can get flooded, which will result in overflowing river deposits of silt on the valley floor.
- Lake District: Settlements
- East Anglia: Settlements
Upland Area - Lake District:
In the Lake District, isolated settlements are left far apart, while most places are farms with lots of land, instead of houses. Also, there will be many campsite areas with these kinds of areas quite dispersed too, due to the fact that the environment of the mountains and velleys does not cater for much development.
Lowland Area - East Anglia:
In East Anglia, you find many more smaller, and more connected villages which are usually located a lot closer together as a result, while there are also no landscape features to get in theway of development either.
- Lake District: Building Materials
- East Anglia: Building Materials
Upland Area - Lake District:
The building materials used gere will most likely be sourced quite locally, as it will prove difficult and costly to transport anything from anywhere very far. This means materials such as slate, stones and woods will be used more.
Lowland Area - East Anglia:
The traditional building materials have always been the local chalk and rock sourced from the nearby areas. However, there are more ranges of building materials used today, as there are a lot more viable and reliable methods of transportation for the materials, making them more cost effective and avaliable.
- Lake District: Field Boundaries
- East Anglia: Field Boundaries
Upland Area - Lake District:
From a birds-eye view, fields are not divided by exact straight lines and boundaries, and instead almost flows in and out of each other, in accordance with how the land is shaped.
Lowland Area - East Anglia:
Overall, in the lowlands, field boundaries are very accurate boundaries that have been carefully drawn out, and they also do not have to be made in line with the contours and shape of the surrounding landscape, unlike the Lake District.
- Lake District: Farming
- East Anglia: Farming
Upland Area - Lake District:
Nearly all the farmers in the Lake District will not grow crops, as they won’t be able to survive the harshest winters, while cattle like sheep and cows are more likely to. These types of animals will be able to eat much more gard and thorny foods, while the sheep influence the fact that stone walls are made to pen them in, so they don’t escape.
Lowland Area - East Anglia:
The type of farming that will take place here is actually crop farming that will be harvested every so often when the crops are ready. This means that large gillages are found around these farmlands, with there being flat land, with little trees (less than 12% of the UK’s trees remain).
- Lake District: Economic Activity
- East Anglia: Economic Activity
Upland Area - Lake District:
Afforestation has happened a lot since the 1920’s on Ennerdale Valley, which proved conomic value in planting trees commercially. Also, the main income will be of sheeps’s wool, as well as sheep and cow as well.
Lowland Area - East Anglia:
In this area, there is a lot more crop farming while there will be a lot more tertiary secotors and jobs avaliable in the market, because there are more densly populated areas, which means more people will need access to shops, doctors, hospitals, facilities and even more; while in the Lake District, there is no need or demand for this.
How does Seasonality impact Coastal Erosion
The differences in temperature have an impact on processes along the coast, e.g the mild temperatures increase the rate of salt weathering because the water evaporates quicker.
How does Storm Frequency impact Coastal Erosion
Storms are very frequent in winter, the stronger winds create high energy, destructive waves which increases the rosion of cliffs. Intense rain makes cliffs more saturated, making mass movement more likely.
How does Prevailing Winds impact Coastal Erosion
The most commom winds in the UK are South Westerlies which bring storms in from the Atlantic, which exposes the South West coast. Cold Northerly winds are also common on the East Coast.
How does Mass Movement (Rotational Slumping) impact Coastal Erosion
Mass movement is the shifting of loose rocks and loose material down a slope. In this scenario, the sand is permeable and allows water to pass through, all the way up to the boundary between the clay and the sand (this lubricates the boundary). The water can’t pass through the impermeable clay, making the sand fully saturated, which will make it dramatically slump in a rotational manner.
How does Mass Movement (Rock Slides) impact Coastal Erosion
Joints or bedding planes are aligned diagonally to the sea, meaning there is erosion the the base, or weathering at the top of the cliff. Then, the cliff becomes unsupported and can be further lubricated by rain, falling in a straight and diagonal line.
How does Weathering impact Coastal Erosion
There is freeze-thaw, biological weathering, and chemical weathering. The freeze-thaw can operate in sub-zero temperatures and is when frozen water get in and enlarges cracks in rocks. Biological weathering is when animals and plant roots burrow down into the cracks and openings in the rock, which in turn, makes it weaker and increases the cracks. Chemical weathering (carbonation) breaks down rocks with acid rain, for example.
What is Abrasion
Broken rock fragments and pebbles carried in the wave ‘batter’ and ‘scour’ the land by hitting the cliff face and the floor. This then breaks off other pieces of rock and rubs surfaces down.
What is Hydraulic Action
When a wave crashes against the land, it compresses air and water and traps into cracks on the rock’s surface. When the wave moves away again, the compressed air expands explosivly. Both these actions enlarge the cracks and ultimatly breaks the rock off.
What is Attrition
When rock fragments grind and rub each other down into smaller and smaller fragments. For example, rocks are smoothed to pebbles which are eventually reduced to shingle and then sand.
What are the Characteristics of Destrcutive Waves (Explanation+List)
These waves will be higher and more powerful, but roll in more frequently (at around 10-14 waves each minute). This type of wave will bring more sediment out and away from the shore/beach, as the backwash is more powerful than the swash. Storms increase the erosional power of destructive waves which can lead to increased rates of erosion. This type of wave tends to narrow and steep-off cliffs, with the strength, the time and the distance needing to be larger in order of this wave to be formed
- Weak swash
- Steep Gradient
- Short Wavelength
- Strong Backwash erodes shore/beach
What are the Characteristics of Constrcutive Waves (Explanation+List)
This type of wave will bring more sediment in, meaning they deposit materials such as sand and shingle (gravel) along the coast to form beaches. This type of wave is associated with light winds and short fetches, meaning it has lower energy, therefore making it less powerful and comes in less fequently. This makes beaches wider but also shallower too. These waves will come in from sheltered areas, as the strength, distance and time will be shorter.
- Strong swash deposits washed up materials
- Shallow Gradient
- Long Wavelength
- Weak Backwash
What does More Resistant (Hard) Rock consist of? (What it’s made of + Examples)
Comsists of resistant rocks, such as igneous granite and resistant sedimentary rocks e.g sandstone, limestone or chalk. Some examples are FlamboroughnHead (East Yorkshire) and Lulworth Cove (Dorset).
What does Less Resistant (Soft) Rock consist of? (What it’s made of + Examples)
Less resistant rocks like shales, which is easily eroded. Examples are Holderness Coast (East Yorkshire), which Christchurch Bay (Doreset and Hampshire) and the North Norfolk Coast.
What are Joints
Joints are small, usually vertical, cracks found in many rocks. More joints mean weaker rock, no matter how strong the rock itself is.
What are Faults
Faults are larger cracks caused by past tectonic movements, where rocks have moved. The more faults, the weaker the rock, no matter what.
Discordant Coastline:
- Definition
- Rock Alignment
- Examples of Coastline
- Features and Landforms
- Erosional Landforms, Depositional Landforms, or both
Definition:
If strata are at right angles to the coast, the coast is known as discordant. These have different rock types.
Rock Alignment:
Rock layers are perpendicular to the coast.
Examples of Coastline:
E.g Swanage Bay, Studland Bay, and Dingle Bay.
Features and Landforms:
Arches, stacks and stumps can be found here.
Erosional Landforms, Depositional Landforms, or both:
Coastal Erosion and Depsoitional Landforms can form here (so both).
Concordant Coastlines:
- Definition
- Rock Alignment
- Examples of Coastline
- Features and Landforms
- Erosional Landforms, Depositional Landforms, or both
Definition:
If strata are parallel to the coastline, the coast is known as concordant. These have the same rock types parallel to the coastline.
Rock Alignment:
Rock layers are parallel to the coastline.
Examples of Coastline:
E.g Lulworth Cove in Dorset, and Flamborough Head in East Yorkshire
Features and Landforms:
They can either be featureless, or there can be some coves created if there are enough weak points in the rock.
Erosional Landforms, Depositional Landforms, or both:
Just Coastal Erosion Landforms are present here.
How do Headlands and Bays form?
They are initially different bands of stronger rock and weaker rock. Then, the sea attacks and erodes a section of the coast with the weaker rock, eroding the weaker rock at a quicker pace, with the stronger rock eroding at a far slower place (and essentially staying put). This erosion of mainly hydraulic action and abrasion then leaves behind headlands that jutt out into sea, and what was the softer rock has now retreated into a sandy beach inside of a bay. This bay continues into the land and the bay continues to retreat until it flattens out with the rest of the land.
How do Arches, Stacks and Stumps form?
Headlands are usually made of more resistant rocks that have weaknesses like cracks, joints, or faults. When waves crash into the headlands and enlarge the cracks in these rocks, mainly by using hydraulic power and abrasion, more erosion continues to take place, therefore leading these cracks to eventually widen out into a cave.
Even more continued erosion like abrasion pushes the cave back and widens it out up to a point where it passes through the whole of the headland to make an arch.
Erosion at the bottom of the arch, and chemical weathering, for example, at the top of the arch wears away the rock at the top and the bottom, until the overhanging rock that connects both sides of the arch eventually falls down, which makes a stack in it’s place.
After even more time, the stack is weathered at the top and eroded at the bottom until it either just shrinks down into a stump by the weathering, or through erosion where part of it breaks off, and topples and falls down into the sea to make a stump.
