envi sci aqa - lithosphere + soils

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sav

Cards (149)

What is the lithosphere?
- the lithosphere is made up of the solid crust and upper mantle it includes rocks mineral resources and soils that provide services that are important to human societies
Why is copper important?
- important for electric cables and water pipes
Why is iron important?
- important for construction of transport such as ships, road vehicles, rail-tracks
Why is aluminium important?
- important for construction of vehicles and aircraft
What is zinc important?
- used for galvanising process which gives steel a rust resisting surface
Why is uranium important?
- nuclear fuel for power stations
Why is neodymium important?
- used for large strong magnets such as in wind turbines
Why is yttrium important?
- used in LED lights
Why is mercury important?
- used in thermometers
Why is indium important?
- it is used in a lot of electronics
Why is gallium important?
- it is used in a lot of electronics such as solar panels
Why is gravel and sand important?
- they are both used in construction, sand for mortar and gravel for concrete
Why is limestone important?
- it is used in construction for building blocks and crushed for road surfacing
Why is China clay important?
- it is used in paints, cosmetics and pharmaceuticals
Why is granite important?
- used in construction for building blocks and kitchen worktops
Why is rhenium important?
- used in x-ray machines
Why is lithium important?
- used in lithium batteries
Why is tungsten important?
- used to make tungsten carbide which makes excellent drilling/cutting tools
What does finite mean?
- mineral resources are finite/nonrenewable meaning there is a limited number of them and they will run out eventually
What are geological processes that create mineral deposits?
- geological processes concentrate these minerals into deposits so they can be exploited by humans for example:
- igneous processes
- metamorphic processes
- sedimentary processes
What are igneous processes?
- process by which rocks created by the cooling and hardening of magma or molten lava
hydrothermal deposition:
- superheated water (magma) dissolves many minerals from the surrounding rock
- this water travels along hydrothermal veins away from the batholith cooling, as they cool dissolved minerals are crystallised and deposited in predictable order according to their solubility
- the least soluble minerals crystallise first
- this process of fractional crystallisation means that a mixture of minerals that couldn't have been exploited can now be separated and deposited for later exploitation
What are igneous rocks?
- they are formed when molten magma or lava cools
- the size of the crystal depends on the rate of cooling
- slow cooling results in large crystals
- they are hard and resistant to wear e.g. granite
What are intrusive/extrusive rocks?
intrusive
- below surface and large crystals as cool slowly
extrusive
- above ground and small crystals as cool fast
What are metamorphic processes?
- when high temperatures and pressure (not melting) alter existing rocks
- e.g. limestone turns into marble under high temps and pressure
What are sedimentary processes?
- processes that cause minerals to settle and build up to produce layers of deposited sediment for example:
- proterozoic marine sediments
- alluvial deposits
- evapourites
- biological sediments
- precipitation
How do you proterozoic marine sediments form?
- they were formed around 2 billion years ago when dissolved iron in the ocean became oxidised by oxygen released by the first photosynthetic organisms
- therefore producing iron oxide deposits at the bottom of the ocean
What are alluvial deposits?
- they are processes which involve material that has been carried and separated by flowing water for example:
placer deposits
- when a river flows into the sea/lake
- the water flow slows down and the sediment is deposited
- over time the sediment gets compacted together therefore forming rock deposits
plunge pool deposits
- when the sediment flowing along a river falls into a plunge pool (waterfall) and cannot escape forming a deposit
What are evapourites?
- formed when water is evaporated and leaves behind dissolved minerals such as halite
What are biological sediments?
- processes where living organisms form mineral deposits for example:
- shells of marine organisms can form chalk and limestone
- the partial decay of marine organisms form crude oil and fossil feels
How does precipitation form deposits?
- formed when dissolved minerals precipitate out of a solution (come out of a solution)
What is the Lasky's principal?
- in general as the purity of a mineral decreases the amount of the mineral present increases exponentially
- therefore there needs to be more methods developed for exploiting low-grade deposits
What is a reserve?
- the amount of a resource which can be exploited with existing technology
What are the different types of reserves?
inferred reserve
- the presence of the mineral can be predicted from knowledge of a geological structures present but not enough is known to estimate the amount
probable reserve
- sufficient information about the deposit is known so the amount of the mineral that can be extracted can be estimated with sufficient accuracy
proven reserve
- sufficient exploration has been carried out including trial drilling to accurately estimate the amount of mineral that can be extracted
What is a resource?
- all the material of a substance that is theoretically available for exploitation
What is the stock?
- all of the material that exists in the lithosphere
What is remote sensing?
- it involves any technique that gives information without taking direct samples
What are all the different survey techniques to locate mineral deposits?
- seismic surveys
- gravimetry
- magnetometry
- resistivity
- trial drilling
How do seismic surveys work?
- involves sound waves produced by controlled explosions on the surface
- echoes from the explosion can give information about the depth, density and shape of the rock
How does gravimetry work?
- gravimeters detect variations in gravity caused by variations in density and mass
- this information can be used to identify which rock is
How does magnetometry work?
- magnetometers detect rocks that are more magnetic such as iron ore