Topic 4: UK's Evolving Physical Landscape Flashcards
Give a definition, approximate age and 3 examples of igneous rocks and sedimentary rocks?
Igneous Rocks: Created when magma or lava cools, e.g. Granite, Basalt, Diorite
Sedimentary Rocks: Layers of sediment are compacted together, e.g. Chalk, Clay, Sandstone
Metamorphic Rocks: When other rocks have been changed by heat or pressure, e.g. Slate, Schist, Marble
Compare the formation and characteristics of granite and carboniferous limestone?
Granite: Contains crystals of quartz, feldspar and mica.
Igneous
Very resistant
Carboniferous Limestone:
Permeable
Sedimentary
Generally resistant
Compare the formation and characteristics of chalk and slate?
Chalk
Very porous
Medium resistance
Sedimentary
Slate
Very resistant
Metamorphic
Explain when and how active volcanoes shaped the uplands of the UK?
520 million years ago, the land that now makes up the UK used to be much closer to a plate boundary than it is now. Active volcanoes forced magma through the earth’s crust which cooled to form igneous rocks.
Explain how glacial erosion and deposition shaped the UK uplands?
Eroded the landscape, carving out U-shaped valleys in upland areas such as the Lake District.
Deposited lots of material as they melted. Landscapes formed by glacial meltwater and deposits extend south of the ice sheets. E.g. large parts of eastern England are covered in till (an unsorted mixture of clay, sand and rocks) deposited by melting glaciers.
Explain when and how sedimentary rock was formed across the UK Lowlands.
Tiny shells and skeletons of dead sea creatures.
From mud and clay minerals.
Explain how glacial deposition shaped the UK Lowlands?
Dry valleys are found in UK lowland landscapes. These are valleys with no streams visible (they flow underground in the permeable chalk). They formed during glacial periods when the colder climate led to more freeze-thaw weathering and glacial snow melt meant that streams had much more water in them than they do today.
Explain how scarp and vale topography forms in the UK Lowlands?
Erosion has left alternate strata of more and less resistant rock to form a landscape known as scarp and vale topography.
Compare the weathering that is found in the uplands and lowlands?
Lowlands: Chemical weathering, biological weathering
Uplands: Freeze-thaw weathering
Compare the soil/rock movement processes in the uplands and lowlands?
Lowlands: Soil creep (rain dislodging soil particles)
Uplands: Rockfalls, landslides
Compare Misfit Rivers and dry valleys (location, characteristics, formation).
Misfit rivers: small rivers that flow in large U-Shaped valleys, when glaciers melt. Uplands
Dry valleys: no streams visible because they flow underground in permeable rock. Lowlands
Explain how glaciers have affected both landscapes?
The ice eroded the landscape. The ice also left distinct landforms when it melted, e.g. hanging valleys.
Explain 2 ways humans have affected the Upland landscape?
Sheep - sheep farming takes place in the harsher conditions in the up,ands. Led to a lack of trees on the hills (young trees are eaten or trampled before they get a chance to mature).
Built dry stone walls as field boundaries.
Explain 2 ways humans have affected the Lowland landscape?
Arable - flat land with good soil is used for arable farming (growing crops)
Hedges used as field boundaries.
What is a concordant coastline? Landforms? Example?
Hard rock
Coves
Durlston Head to Kimmeridge
What is a discordant coastline? Landforms? Example?
Hard and soft rocks
Headlands and bays
Studland to Durlston
What are joints and faults and how do they affect erosion?
Joints: small cracks
Faults: larger cracks
Increase rate of erosion
How are headlands and bays formed?
The less resistant rock is eroded quickly, whereas the more resistant rock is eroded more slowly.
This leaves rock jutting out (headland) and rock further inland (bay).
How are wave-cut platforms made?
Waves create a wave-cut notch.
Collapses and leaves a pile of debris.
Over thousands of years the cliff will retreat through this process
What are the characteristics of arch, stacks, stumps?
Cracks in a headland
Cracks enlarged by waves to make a cave
Erosion breaks through to the other side to make an arch
Arch collapses and leaves a stack
Stack erodes down to leave stump
Characteristics of destructive waves?
Tall
Short wavelength
Weak swash
Strong backwash
Characteristics of constructive waves?
Low
Longer wavelength
Strong swash
Weak backwash
What is mass movement?
Rotational slumping - wet rocks shifting down a slope in a rotation
Rock slides - loose material shifting down a slope in straight line
Increase erosion
What are the different types of weathering?
Biological - break down of rocks by living things, e.g plant roots widening cracks
Chemical weathering - break down of rocks by changing its chemical composition, e.g rainwater & seawater dissolve rocks
Mechanical weathering - water gets into cracks, expands and breaks the rock
