Component 2 Topic 4 Flashcards
How are igneous rocks formed?
Igneous rocks form when molten rock cools and hardens. Igneous rocks are usually old and hard, especially compared to sedimentary rocks. (E.g. granite)
What are sedimentary rocks formed from?
Sedimentary rocks are formed by compacting and compressing lots of sediments into one rock. (E.g. chalk is formed when shells and skeletons of dead sea creatures compress together.)
Describe how metamorphic rocks are formed.
Metamorphic rocks are formed when different types of rock are changed by heat and pressure, therefore creating much harder and compact rocks (e.g. shale becomes slate)
Give two ways in which tectonic activity has shaped the uk landscape.
Active volcanoes and plate collisions have both shaped the uk landscape. The land which is currently the uk us to be much closer to a plate boundary, and active volcanoes forced magma to the surface which was then cooled to form hard igneous rocks.
Historic plate collisions caused the rocks to be lifted and folded forming mountain ranges (e.g. Scottish highlands and the lake district)
Outline the characteristics of slate and schist.
Schist is formed when slate is pressurised and heated to form a new and harder rock. Schist is harder and much denser than slate. Both are impermeable and very resistant to weathering. However, both can be easily split into thin slabs.
Explain how the uk has been shaped by glacial periods.
Large ice sheets called glaciers shaped the uk land ape by eroding and carving into the landscape to form steep āuā shaped valleys in upland areas. Glaciers also deposited lots of material when they melted. (e.g. a lot of eastern england is covered in material which was deposited by melting glaciers)
Give three physical processes that alter the landscape
Weathering, erosion and slope processes
Give an example of a lowland landscape
The downs and the wealds are lowland landscapes in the UK
Outline how physical processes have shaped the uk landscapes
Lowland landscapes would have been formed over a number of years through different processes such as erosion and freeze thaw weathering. Many lowland areas would have been formed just after the glacial periods when the colder climate led to more freeze thaw weathering which created the distinct landscapes.
How does forestry alter the landscape?
Forestry has changed the landscape by making it look a lot less natural through planting trees in unnatural straight lines. Forestry is the management of woodland areas, meaning previous woodland areas that have been cut down can be restored and conserved through the plantation of new trees.
How does settlement alter the landscape?
Settlements can alter the landscape if the ground is required to be flattened or risen in order to make suitable space for housing. Settlements has also meant that concrete would have been placed and rivers would have been diverted and straightened in order to prevent flooding.
How does salt weathering break up rock?
Salt weathering breaks up rocks when the sea water gets into the cracks of the rocks. The sea water then evaporates and salt crystals form and expand, putting pressure on the rock. If this process repeats the cracks will widen and the rock will break.
What is hydraulic power erosion?
Waves crash against rock and compress air into the cracks, putting pressure on the rock, and constant pressure will lead to the eventual breakdown of the rock.
What is abrasion?
Eroded particles in the water scrape and rub against rock removing small pieces.
What is attrition?
Eroded particles in the water smash into each other and break into smaller pieces.