Topic 4 - Uk Physical Landscape (set C)✔️ Flashcards
Explain how igenous rocks are formed?
Formed when molten rock (magma) from the mantle cools down and hardens - the rock forms crystals as it cools
Features of igneous rock and an example of an igneous rock?
Igneous rocks are usually hard - e.g. granite
How are sedimentry rocks formed?
Formed when layers of sediment are compacted together until they become solid rock
Give two exmaples of the main sedimentry rocks in the UK, their features and how they are made?
- carboniferous limestone and chalk (formed from tiny shells and skeltons of dead sea creatures) - limestone is hard but chalk is much softer
- clays and shales (made from mud and clay minerals) they are very soft
Explain how metamorphic rocks are formed? Example of a rock formed this way?
Formed when other rocks (igneous , sedimentry or older metamorphic rocks) are changed by heat and pressure - the new rock becomes harder and more compact - and example is shale which becomes slate and with further pressure become schist
What type of rocks are formed in the north of the UK? Are they harder of softer?
Harder rocks like:
- igenous rocks
- metamorphic rocks and schist
- carboniferous limestone
What type of rocks are found in the south of th UK? Are they harder of softer?
Softer rocks like:
- clays and sandstones
- chalk and mudstones
How have volcanos skaped the UK landscape?
Active volcanos forced magma through the earths crust which cooled and formed igneous rocks for example granite
How did plate collisions shape the UK landscape?
- plate collisions caused the rocks to be folded and uplifted, forming mountain ranges, for example the scottish highlands - the igneous granite is hard and more resistant to erosion
- the intense heat and pressure caused by plate collisions formed hard metamorphic rocks
Explain how plate movements shaped the UK landscape? Include refrence to the formation of rocks?
- plate movements meant Britian was in the tropics and higher sea levels meant it was partly underwater - carboniferous limestone formed in the warm shallow seas
- youngest rocks in the uk were formed in the south of England - chalks and clays formed in shallow seas and swamps, which are softer and easily eroded - they form lowland landscapes
3 Features of granite?
- very resistant, found in upland landscapes
- has lots of unevenly spread joints (cracks) areas that have fewer joints are weathered more slowly which results in them sticking out at the surface forming tors
- granite is impermeable
Explain how granite is responsible for creating moorlands?
Granite is impermeable so it does not let water through which creates large areas of waterlogged land and acidic soil with low-growing vegetation (moorlands)
3 features of slate and schist?
- slate forms in layers creating weak planes of rock
- generally hard and resistant to weathering - but easily split into small flakes
- often form rugged upland landscapes - they are impermeable which can lead to moorland
2 features of carboniferous limestone?
- rainwater slowly eats away at limestone through carbonation weathering which mostly happens along joints in the rock which can creates caverns and gorges
- is permeable so limestone areas have dry valleys and resurgent rivers
What are resurgent rivers? what are they caused by?
Rivers that pop out at the surface when limestone is on top of impermeable rock
3 features of chalk and clay?
- chalk is harder than clay and forms escarpments (hills) in the uk lowland and cliffs at the coast
- chalk is permeable - water flows through it and emerges as a spring where it meets impermeable rock
-clay is very soft and easily eroded - forms wide flat valleys with lots of streams and rivers as clay is impermeable
How did ice change the UK landscape?
Ice is powerful so it was able to erode the landscape, carving out large u-shaped valleys in upland areas like the Lake district
How have Glaciers shaped the UK landscape?
Glaciers have deposited lots of material as they melted - landscapes formed by glacial meltwater and deposits extend south of the ice sheets
Define weathering?
Breakdown of rocks into smaller pieces - it can be mecahnical,chemical or biological
Define erosion?
Erosion wears away rock - rivers and the sea now constantly erode the landscape
How do post-glacial river processes alter the landscape?
Melting ice at the end of glacial periods make rivers much bigger than normal with more power to erode the landscape
Give 4 physical processes that erode and change the landscape?
- erosion
- weathering
- post-glacial river processes
- slope processes
What are slope processes?
Include mass movements eg rockfalls, slides , slumps and soil creep
Explain how Snowdonia has been affected by physical processes?
- has a large basin - hollowed out by ice during glacial times
- large u-shaped valley was eroded by ice and contains misfit rivers
- lots of rain and the rock is impermeable so there are lots of streams which cause erosion
How have humans changed the landscape through agriculture?
- cleared forests to make space for farming
- hedgerows and walls have been put in to mark out fields
What type of conditions are best for arable,dairy and sheep farming?
- arable - flat land and good soil is used for growing crops
- dairy - warm and wet areas which have lots of large, grassy fields
- sheep - takes place in harsher conditions and has led to a lack of trees on hills (due to young trees being eaten or trampled)
How have humans changed the landscape through foresty?
- coniferous forests have been planted for timber - forests look unatural and are planted in straight lines
- very little natural deciduous woodlan left
Define forestry?
The management of areas of woodland - they can be used for timber, recreation or conservation
How have humans changed the landscape through settlement?
- land was concreted over for roads and buildings - which has affected drainage patterns
- some rivers were diverted through undeground channels
- river channels were straightend or had embankments built to prevent flooding
what factors influence where settlements have developed?
- water supply
- being easy to defend
- sheltered from wind and rain
