Mineral Resources Flashcards
Why is resource extraction important for society?
- Metals and metal ores
- Industrial minerals
- Construction materials
What is a mineral?
A valuable or useful chemical substance formed naturally in the Earth’s surface
What is a mineral deposit?
A rock that contains at least one mineral
What is an ore?
A rock containing a mineral at a purity high enough to be extracted economically
What is iron used for?
- Reinforced concrete in construction
- Railway lines
- Appliances
What is uranium used for?
- Nuclear fuel
- Concrete production
- Sterilising soil
What is gold used for?
- Jewellery
- Electronics
- Defence
Why is mineral extraction non-renewable?
Mineral resources are formed too slowly to be replaced within timescales that would allow human use
What is a sedimentary rock?
A rock formed on or near the Earth’s surface due to compression of ocean sediments
Which processes lead to sedimentary rock formation?
- Weathering
- Erosion
- Deposition
What are some examples of sedimentary rocks?
- Sandstone
- Limestone
- Chalk
- Coal
What is an igneous rock?
A rock formed when magma cools and re-crystallises
Which processes lead to igneous rock formation?
- Subduction
- Melting
What are some examples of igneous rocks?
- Gabbro
- Granite
- Andesite
- Basalt
What is a metamorphic rock?
A rock which has been re-crystallised into another rock due to pressure and heat
Which processes lead to metamorphic rock formation?
- Plate tectonics
- Heat
- Pressure
What are some examples of metamorphic rocks?
- Slate
- Marble
- Gneisst
- Quartzite
What are the 5 sedimentary geological processes?
- Proterozoic marine sediments
- Alluvial deposits
- Secondary enrichment
- Evaporites
- Biological deposits
What is another term for the compression of ocean sediments?
Lithification
When were Proterozoic marine sediments formed?
2.5 - 1.8 billion years ago
What is another name for Proterozoic marine sediments?
Banded iron formations
How were Proterozoic marine sediments formed?
- First photosynthesisers increased O2 concentration in oceans and then atmosphere
- Iron ions were present in solution and were oxidised
- Solid iron oxide was formed (FeO) which formed deposits on the ocean floor
What are examples of Proterozoic marine sediments?
- Haematites
- Magnetites
How are alluvial deposits formed?
- Rivers with high energy and velocity transport large volumes of sediment
- Reduced energy and velocity causes deposition
- Heavier and denser sediments precipitate out of solution first
Where is alluvial deposition most likely to occur?
On river meanders
What are examples of alluvial deposits?
- Gold
- Diamond
- Tin ore
What is the process of secondary enrichment?
- Metal ore is exposed on the surface to O2 and H2O due to erosion
- Metal oxidises and dissolves before percolating downwards until it reaches the water table
- The ore is reduced when it reaches the anaerobic saturated zone beneath the water table
- Metal ore precipitates out of solution and forms a concentrated deposit below the water table
What is an example of a deposit formed by secondary enrichment?
Uranium ore deposits in sandstone
How do evaporites form?
- Sea level decrease causes oceans to become landlocked
- Salt precipitates out of solution and crystallises as water begins to evaporate
- Salt is deposited on land and may become buried
What is the main example of an evaporite deposit?
Common salt (halite/NaCl)
What is an example of evaporite extraction?
Winsford Salt Mines, Cheshire - supplies 50% of the UK’s road salt
How do biological deposits form?
The remains of living organisms are lithified over time and concentrate minerals in sedimentary rocks
What are some examples of biological deposits?
- Coal
- Oil
- Limestone
- Chalk
What is coal formed from?
Terrestrial vegetation
What is oil formed from?
Microscopic marine organisms
What are limestone and chalk formed from?
Shell remains of marine organisms
How are metamorphic rocks formed?
Igneous processes and tectonic movement causes existing rocks to re-crystallise due to heat and pressure