The Lithosphere (the physical environment)

The lithosphere

The solid/rocky outer layer of the Earth including the crust and upper mantle

Non renewable materials

Materials that form at a slow rate and cannot be replenished

Mineral ores

Rock/solid material from which valuable minerals can be extracted for economic gain

Hydrothermal deposition process

A batholith- made of granite, hot, igneous

1- Rain water percolates down into an aquifer

2- water is superheated (above boiling) yet under pressure so no evaporate

3- superheated water dissolves minerals that surround the batholith

4- dissolved minerals flows up away from batholith

5- as liquid cools minerals precipitate out of solution from least to most soluble

6- results in deposits that are economically exploitable because minerals arent all mixed up, they are separated deposits

How are igneous rocks formed?

Volcanic rock created by cooling and hardening of magma

Metamorphism

The process of recrystallisation of sedimentary rock due to exposure to high pressure temperature or molten rock at plate boundaries

Recrystallisation

The reorganisation of atoms within a rock to form a new rock type

Sedimentary rock

Rocks formed by the accumulation and deposition of sediments

Proterozoic marine sediments

The formation process involving the combination of oxygen from Cyanobacteria and iron in seawater leading to the formation of insoluble iron oxide that sinks to the ocean floor over time, you get iron ores from this

Placer deposits

Mineral deposits formed by the sudden slowing of the high velocity water, such as in rivers concentrating dense unreactive materials together for example gold nuggets

Enriched uranium

lots of water flowing through oxygen rich sandstone with low grade uranium, reaches an area where there is low oxygen and lots of water, and creates a redox boundary, it becomes chemically reduced and insoluble and precipitates out of solution

Evaporite formation

The process in which a section of the ocean evaporates leaving behind salt deposits

Biological sediments

Sedimentary rocks formed from the remains of living organisms such as limestone, coal, oil and gas

What’s coal made from

Dead terrestrial plants

What’s oil made from

Dead marine plankton

Example of metamorphic reaction

Limestone to marble

Magnetometry

A survey method that measures variations in the earths magnetic field caused by magnetic ore bodies using a magnetometer

Gravimetry

The detection of variations in the earths gravitational field using a gravimeter which can be land based or air based used to locate dense metallic ores such as gold or copper

Satellite surveys

Utilizing satellites as for data collection including infrared spectroscopy to identify mineral deposits,

advantage - covering large areas quickly without disturbing habitats

Seismic surveys

Involves creating loud sound or vibrations that travel underground to measure reflection time at geological boundaries while commonly used for oil and gas deposits it can also cause noise pollution

Resistivity surveys

The measurement of the ease at which an electrical current flows through rocks

Trial drilling

the process of drilling boreholes to determine depth, purity and chemical form of deposits it allows for taking physical samples for economic viability assessment

Cut off ore grade

The minimum purity of an ore body required for economic viability eg. 35g of copper per kg, this is used to delineate (indicate the exact position of) the economically viable mining area on a map

How are IR surveys used to detect deposits

IR is emitted from the ground and the wavelength emitted can depend on the rock types below the surface

Which rocks have the highest resistivity

A rock with no water

The stock

All of the material that can be found in the lithosphere including the minerals we will never be able to extract

The resource

Encompasses all the material that could theoretically be exploited in the future with improved technology and increased pricing even if it cannot be exploited currently

The reserve

The proportion of the minerals we can extract right now economically using existing technology and prices available

Lasky’s principle

As the purity of the mineral decreases, the quantity of the mineral on earth increases exponentially meaning although low grade ores have a low purity because there are so many of them that have not been extracted from there is huge amount available ore to mine

Why would a logorythmic scale be used for laskys principle

To represent a wide range of values

Factors determining if an ore is economically viable

The ore purity must be high enough to ensure a profit, determined by COOG, overburden, hydrology, land use conflict,

Mineral deposit

A rock containing at least one valuable mineral

Deep mining is used to…

Used to extract ore body deep underground

Overburden

The rock situated above the mineral deposit that will need to be removed in order to extract the ore

Open cast mining

Surface mining technique that creates large shallow pits

Dredging

method used to extract minerals from submerged deposits

Viability of a mine

Factors affecting the profitability and practicality of mining a site

Hydrology of a mine site

Describes how water moves through the mine and it’s impact on operations affected by permeability of rock type

how mining causes habitat loss and how to reduce

Caused most by open cast mining as large portion must be removed for access to shallow wide deposits eg trees may need to be felled, deep mining causes less

To reduce this they could pledge to restore the habitat once extraction is complete eg. Eden project, may need permission to mine if there is a protected species there which needs relocating first

How mining produces dust pollution (impacts and how to reduce)

Material removed via explosions causes large amounts of particulate matter into the atmosphere, large machinery can kick up dust,

impacts- can cause respiratory issues for animals and reduce photosynthesis if settled on plants

To reduce you can spray water in the air makes it dense so it falls to the ground reducing the mobility and severity as a pollutant

How mining produces noise pollution + impacts and how to reduce

Vehicles and explosives can change behaviour of surrounding animals causing stress responses, death or prevent breeding, people living by will also be disturbed

To reduce they can instal baffle mounds to absorb and deflect noise, mining could only take place during the day and warnings can be given to locals

How mining produces GHG

large mining machinery usually runs on fossil fuels and the combustion releases GHGs into the atmosphere which absorb infrared radiation and contribute to global warming

To reduce electric/hydrogen powered machinery would be best as they don’t release or involve internal combustion

How mining produces habitat fragmentation + impacts and how to reduce

Caused by the building of transport routs for machinery decreasing gene pool,

To reduce use animal crossings such as bat bridges can be used

How mining produces spoil heaps + impacts and how to reduce

Large accumulations of solid waste material brought out of a mine which is then piled up reducing the amenity, can produce toxic leachate (acid mine drainage) when precipitation percolates through and dissolves metals giving the solution an acidic pH leading to animal death

To reduce trees can be planted on the heaps to make them blend in, this also makes them more stable due to root networks drainage water can be collected and neutralised using calcium carbonate for eg reducing the solubility of the metals

How mining produces turbidity impacts + how to reduce

If mines flood then water is likely to be turbid which reduces light intensity in bodies of water killing submerged plants

To reduce, keep water still so sedimentation can occur

Directional drilling

Method to access minerals without disturbing habitats used for certain minerals like oil and gas, drill can move horizontally

Acid mine drainage formation

Formed from precipitation through spoil heaps the leachate is acidic so readily dissolved heavy metals in the spoil making it toxic

Subsidence

Ground slipping above the mine causing minor structural damage addressed through compaction and support pillars

Smelting

The process of using high temperatures to chemically reduce ores separating the metal from its ore

Extracting techniques from spoil heaps

Bioleaching utilises fungi/bacteria to oxidise sulphide ores releasing sulphuric acid and facilitating the extraction of metals from the ores as the metals will become more acidic pHs

Phytomining involves using plants to absorb metal ions from low grade ores which are then incinerated and metals are extracted from the ash

Polymer adsorption

Utilising long chain molecules to extract metal ions from seawater eg. Uranium

Displacement reactions

A process in which a more reactive metal displaces a less reactive metal in a compound enabling the extraction of the desired metal

Method to exploit previously inaccessible deposits

Eg extracting manganese nodules, which will be expensive because of the equipment due to the technology it requires, there may also be land based conflicts as well as legal protection

What are manganese nodules

Nodules found under the seabed containing high volumes of manganese and other metals representing a potential future source of critical minerals

how does pH affect metal solubility in water

Lower pH increases solubility

Circular economy model

Is aimed at extending the useful life of minerals through recycling and reducing the demand for new mineral extraction

Includes the cradle to cradle design where products are designed with the intention of easy recycling at the end of their life contributing to the circular economy and reducing demand for new mineral extraction

Recycling advantages- conserves mineral resources, reduces energy use, minimilizes environmental impacts, contributed to sustainable resource management

disadvantages- difficulties in separating mixed materials potential reduction in product quality and reliance on consumer cooperating for effective recycling

Which process extracts a mineral ore from the rock it’s contained in

Smelting