envi sci aqa - lithosphere + soils

• 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