Topic 3 : UK Geology Flashcards
Describe the characteristics of an igneous rock
Magma or lava cools Cooling: Underground-intrusive rocks Overground-extrusive Very resistant
Describe the characteristics of a sedimentary rock
Small parts of sand, mud and organic material
Sediments accumulates and compresses in layers
Less resistant
Describe the characteristics of a metamorphic rock
Heat and pressure changes the sedimentary + igneous rocks
Resistant
How does a U shaped valley form?
Glaciers alter the V shape to a U shape
Valley glacier moves down
Glacier moves down valley and plucks rock from beneath and those rocks erode
Truncated Spurs interlock
How is a Batholith formed?
Magma intrudes into the ground
Magma cools and solidifies
Large crystals form in the rock
They are domed shape and overtime exposed due to erosion
What is a mudflow?
Mixture of water, rock and sediment
They move very quickly
What is scree?
Angular rock pieces that has been created by freeze-thaw weathering
What are landslides?
A section of soil or rock suddenly gives way and moves down a slope
Name the types of weathering
Chemical
Biological
Physical
What are escarpments?
Higher areas of resistant rocks like chalk
What are vales?
Softer clay form lower and flatter ground
How is a v shaped valley formed?
When a river is near its source, it develops a V-shaped valley as the river erodes down
weathering breaks up material on the valley slopes.
Weathered material from the valley sides gets deposited in the river. This material is carried by the river and erodes the riverbed through abrasion.
What is a dip slope?
Behind the escarpment gentle slopes follow the angle of the scarp
How does physical weathering affect the UK’s landscape?
Uses freeze thaw weathering which shatters the ground
How does chemical weathering affect the UK’s landscape?
Uses acid rain which wears materials away
How does Biological weathering affect the UK’s landscape?
Plant roots can grow in cracks and make them wider and deeper by opening up the cracks as they grow
What type of rock would a sedimentary rock be like?
Soft rock
What type of rock would an igneous rock be like?
Hard rock
What is weathering?
The physical, chemical and biological breakdown of solid rock by the action of the weather and plants
What is rock fall?
When rocks and other sediments fall through the air and land at the bottom of a slope
What are landslides?
A slide happens when a section of soil or rock suddenly gives way moves down a slope
What is mud flow?
Flows are a mixture of water, rock and sediment
Move very quickly
Large flows can bury entire villages
Smaller ones can block roads
What is soil creep?
Very slow mass movement that goes on for years or even centuries
What are concordant coastlines?
When rock layers are parallel to the coastline
What are destructive waves?
Waves that erode the beach
Weak swash
Strong backwash
What are constructive waves?
Waves that build a beach
Strong swash
Weak backwash
What is a headland?
A piece of land jutting out into the sea
What is a bay?
A broad coastal inlet often within a beach
What is a split?
A finger of new land made of sand jutting out into the sea
Why are erosion of cliffs greater in winter?
Destructive waves occur in winter as they are created in stormy conditions
They also have a strong backwash
What is a salt marsh?
Low lying coastal wetland extending between high and low
What is a bar?
A spit that has grown across a bay
What causes cliffs to collapse?
Coastal erosion
What is coastal deposition?
Material being transported is dropped by constructive waves
What is attrition?
When rocks bang against each other and break
What is abrasion?
Process of weathering something away
What is hydraulic action?
Motion of water against a rock surface
What is a wave-cut notch?
A small indentation out into a cliff roughly at the the level of high tide caused by erosion
What is a wave cut-platform?
A wide, gentle sloping rocky surface at the foot of the cliff
What is a fetch?
Distance over which the world has blown
What are the differences between a concordant and discordant coastline?
Discordant coastline is rock layers which are perpendicular to the coast
A concordant coastline is rock layers which are parallel to the coastline
How is a wave-cut platform formed?
Weathering attacks top of cliff
Wave cut notch is formed by erosional processes - this a dent in the cliff
As the notch increases in size, the cliff becomes unstable and collapses
Backwash carries away the eroded material
Process continues - the cliff continues to retreat
What is prevailing wind?
The dominant wind direction
What is hard engineering?
Construction of man-made structures to manage the coastline
What is soft engineering?
Construction of more environmentally friendly, less damaging and arguably more sustainable management solutions
Name types of hard engineering
Sea wall
Groynes
Rock armour
Gabions
Name types of soft engineering?
Beach nourishment
Dune regeneration
Marsh creation
What would you find on the upper course of a river?
V - shaped valley Waterfalls and gorges Shallow water Slowest flow Narrowest part of the river Vertical erosion
What would you find on the middle course of a river?
Meanders River cliff and river beach Ox - bow lake Wider part Lateral erosion
What would you find on the lower course of the river?
Flooding Faster flow Deepest water Widest part Flood plains Deltas
The load particle size, channel bed roughness and slope angle is greater in the………of a river?
Upstream
The discharge, occupied channel width, channel depth, average velocity and load quantity is greater in the………of a river?
Downstream
Explain how two channel characteristics change along a river’s long profile
Discharge changes by getting wider due to lateral erosion
Channel depth changes by increasing due to vertical erosion
What is traction?
Large stones dragged along in the river
What is saltation?
Smaller stones or pebbles are picked up and dropped again
What is suspension?
Tiny particles of sediment are carried in suspension in the river’s current
Describe the formation of waterfall and gorges
Waterfalls occur when a river crosses a bed of more resistant rock
Erosion of the less resistant rock underneath continues
River’s energy creates a hollow at the foot of the waterfall known as a plunge pool
Less resistant rock beneath is eroded more rapidly by abrasion and hydraulic action
Created a hedge which collapses
Waterfall takes up a new position leaving a steep valley or gorge
Describe how a V shaped valley forms
River erodes vertically down and leaves behind V shaped valley sides - it erodes straight down and leaves steep valley sides that are attracted by weathering
This weakens the valley sides which may collapse or move down the slope due to slumping or soil creep
River can then erode this material and move it away leaving behind the V shape
What is discharge?
Volume of water flowing in a river
Measured in cubic meters per second
What is a flood plain?
Flat area of land that the river splits into when it bursts its banks
What are levees?
A small ridge or raised area of land on the banks of the river
Made up of the sediment from the river
Can be natural or man made
How is a river delta formed?
When the river deposits its material faster than the sea can remove it
What is a fan shaped delta?
Land around the river mouth drones out into the sea and the diver splits many times on the way to the sea
What is a cuspate delta?
Land around the mouth of the river juts out into the sea
What is a bird’s foot delta?
River splits on the way to the sea
Each part of the river juts out into the sea
Explain the impact of tectonic processes on the UK’s landscape
Continental drift has shifted the UK’s location from the tropics
Rock has been uplifted from the ocean by tectonic processes to create land
This movement has created faults and distorted the layers of rocks
This has changed the UK landscape
Name the main ways that tectonic activity shaped the UK landscape
Plate movements
Plate collisions
Active volcanoes
How did plate collisions shape the uk landscape?
Mountain ranges (e.g. Scottish Highlands, Lake District) were formed by rocks folding and uplifting as a result of plate collisions. These collisions also generated intense heat and pressure which led to the formation of hard metamorphic rocks in northern Scotland and Northern Ireland.
How did plate movements shape the uk landscape?
345-280 million years ago, the UK was in the tropics. At this time, sea levels were also higher, and so carboniferous limestone ended up forming in the warm and shallow seas.
These areas are now found in the uplands of the Peak District, South Wales and south-west England.
The lowland chalk and clay landscapes of southern England are the youngest rocks in the UK, and these also formed in the shallow seas and swamps all those years ago.
How did active volcanoes shape the uk landscape?
The UK was much closer to a plate margin 520 million years ago.
Active volcanoes at this boundary erupted magma onto the UK landscape, which then cooled to form igneous rocks, such as granite
What does chalk form?
Escarpments
What does clay form?
wide and flat valleys because it is easily eroded
How are the joints spread in granite?
Unevenly spread
Fewer joints mean slower erosion and so these areas can end up sticking out as tors
What type of landscapes does granite form?
Upland landscapes
Why do igneous rocks form upland landscapes?
Because they are more resistance and impermeability
What type of weathering is limestone heavily affected by?
Carbonation weathering
which happens mainly along joints and can end up creating some incredible features, such as limestone pavements and caverns
Why do sedimentary rocks from lowland landscapes?
Because they are less resistant and permeable
How doe u shape valleys form?
When a glacier flows through a v-shaped river valley + ice erodes the surrounding rocks to create a “U” shaped valley with a flat bottom and steel sides
What is a dip slope?
A surface which closes in the same direction as the dip of the underlying rocks
What is a scarp slope (escapement)?
The relatively steel face of a scarp
What is a vale?
Flat area of land
What is an anticline?
Layers of resistant rock at an angle
Explain how humans impact the landscape?
Yorkshire dales:
Local limestone used to construct houses + drystone walls
Glacial boulders removed to improve farmland
Dispersed settlement due to space needed to graze the uplands
Explain the impact of tectonic processes
Continental drift has shifted the UK’s location from the tropics
Rock has been uplifted from the ocean by tectonic processes to create land
This movement has created faults and distorted the layers of rock
This has changed the UK’s landscape
What are the human impacts on the landscape in East Anglia?
Fences/boundaries by use of hedges due to lack of suitable rock to build with
Rich arable farmland
Communal settlements
What are the human impacts on the landscape in the Yorkshire Dales?
Local limestone used to construct houses and drystone walls
Glacial boulders removed to improve farmland
Dispersed settlement due space needed to graze the uplands
What is the predominant rock type in the south and east of the UK?
Sedimentary rock
What is the predominant rock type in the south west of the UK?
Igneous rock
Which type of rock is mainly found on Scotland
Metamorphic
