The UK's Evolving Physcial Landscape Flashcards
What are the three types of rocks?
Igneous
Sedimentary
Metamorphic
How are igneous rocks formes?
Formed when molten rock from the mantle cools down and hardens.
How are sedimentary rocks formed?
When layers of sediment are compacted together until they become solid rock.
How are metamorphic rocks formed?
Metamorphic rocks are formed when other rocks are changed by heat and pressure. The new rocks become harder more compact.
What are the three main ways that past tectonic process have shaped the UK landscape?
Active volcanoes
Plate collisions
Plate movements
Characteristics of Granite
Very resistant and forms upland landscapes.
Has a lot pf joints which aren’t evenly spread
Characteristics of slate and schist
Slate forms in layers creating weak planes in the rock, it is generally hard and resistant.
Schist has bigger crystals than slate
Slate and schist often form rugged upland landscapes
Characteristics of Carboniferous Limestone
Permeable
Characteristics of Chalk and Clay
Chalk is harder than clay, it is permeable
Clay is very soft and easily eroded
What are the physical processes altering the landscape?
Weathering
Erosion
Post-glacial river processes
Slope processes
Weathering
Breakdown of rock into smaller pieces. It can be mechanical, chemical or biological
Erosion
Wearing away of rocks.
Post glacial river process
Melting ice at the end of glacial periods made the rivers much bigger than normal with more power to erode the landscape
Slope process
Includes mass movement
Give an example of a upland landscape
Snowdonia
Give an example of lowland landscape
The downs and the weald
Name how humans have changed the landscape through agriculture?
Agriculture
Forestry
Settlement
How has agriculture changed the landscape?
People have cleared the land of forest to make space for farming.
How has forestry changed the landscape?
Some places, deciduous woodland has been replanted to make the area more a natural state
How has settlements changed the landscape?
Lots of factors have influenced where settlements have developed. For example, early settlements needed a water supply, somewhere that could easily be defended or that sheltered from wind and rain.
Mechanical Weathering
The breakdown of rock without changing its chemical composition.
Explain the main type of mechanical weathering that affects coast - salt weathering
The seawater gets into the rock
When the water evaporates, salt crystals form. As the salt crystals form they expand, which puts pressure on the rock.
Repeated evaporation of saltwater and slat crystals widens the rock and causes the rock to break up.
Chemical weathering
Is the breakdown of rock by changing its chemical composition
Carbonation weathering is a type of chemical weathering that happens in warm and wet environments. Explain what Carbonation weathering is?
Seawater and rainwater have carbon dioxide dissolved in them, which makes them weak carbonic acids.
Carbonic acids reacts with rock that contains calcium carbonate, so the rocks are dissolved by the rainwater
Biological weathering
Breakdown of rock by living things
Mass movement
The shifting of rocks and loose materials down a slope
What are three types of mass movement?
Slides - materials shift in a straight line
Slumps - materials shifts with a rotation
Rockfalls - material breaks up and falls down slope
Waves wear away the coast using three processes of erosion
Hydraulic Power
Abrasion
Attrition
Hydraulic power
waves crash against rocks and compress the air in the cracks, putting pressure on rocks. Repeated compression widens the crack and makes the bits of rock break up
Abrasion
Eroded particles in water scrape and rub against rock, removing small pieces.
Attrition
Eroded particles in the water smash into each other and break into smaller fragments.
Discordant coastlines
Rock layers perpendicular to coast
Headlands and bay
More common
Coastal erosion and deposition landforms
Concordant coastlines
Rock layers are parallel to the coastlines
Unusual
Usually just coastal erosion landforms
Hard rocks
Such as igneous, granite take longer to erode. If they are parallel to the coast they can form a barrier to protect softer rocks
Soft rocks
Soft rocks consist of less resistant rocks such as clays, which are more easily eroded
Joints and faults are cracks and weaknesses in the rock. Describe joints and faults.
Joints - small cracks found in many rocks
Faults - larger cracks caused by past tectonic movements, where rocks have moved
Destructive waves
Are waves that carry out erosional processes.
They are high, steep and have a high frequency.
Backwash is more powerful than their swash. Meaning material is removed from the coast.
Waves erode cliffs to from wave cut platforms. What is wave cut platforms?
It is the platform thats left behind as the cliff retreats.
Explain how waves form wave cut platforms.
1) waves cause most erosion at the foot of a cliff
2) forms a wave cut notch, which enlarges as erosion continues
3) the rock above the wave cut notch becomes unstable and eventually falls off
4) collapsed material is washed away and a new wave cut notch is formed
5) repeated collapsing results im cliff retreating
6) a wave cut platform is the platform left behind as the cliff retreats1
Where do headlands and bay form?
Form along discordant coastlines
How do headlands and bay form?
Form where alternating brands of resistant and less resistant
rock along a coast.
The less resistant rock is eroded quickly and forms a bay
The resistant rock is eroded more slowly and its left jutting out forming a headland
What are headlands made up off?
Made of resistant rocks that have weaknesses like cracks
What causes a cave to form?
Repeated erosion and enlargement of the cracks
Hows an arch formed?
Continued erosion deepens the cave until it breaks through the headland