The living environment: Mineral resources

• metals and metal ores • industrial materials • construction materials

The minerals resources extracted from the lithosphere are non-renewable as they are reformed too slowly to be replaced within timescales that would allow human use. Long-term use relies on an understanding of the scientific methods that will increase supplies, extend use and find alternatives for those in restricted supplies.

• hydrothermal deposition (igneous processes) • metamorphic processes • Proterozoic marine sediments • physical sediments (same thing as sedimentary processes) • biological sediments

Naturally occurring, (mostly) Inorganic Crystalline Solid with a Definite chemical composition

what we can exploit for human use -Metals -Silica -Carbon-based (limestone, fossil fuels)

The relatively hard outer layer of the Earth comprising the crust and upper layer of the mantle. It is the source of mineral resources such as metal ores and affects soil formation and properties.

The deposition of mineral deposits from hot mineral-rich solutions.

Geological processes that change the form of a rock with heat and/or pressure, but without melting it.

These include the iron oxide deposits produced by the reaction of dissolved iron minerals with the oxygen produced by photosynthesis. This occurred in the early Proterozoic era and delayed the build-up of oxygen in the atmosphere.

The process by which rocks and minerals are created by the cooling and hardening of magma or molten lava are known as igneous. Many different igneous processes have produced exploitable mineral deposits. Molten rock (magma) is found in a magma chamber AKA a Batholith It is rich in dissolved minerals With enough heat, they remain in suspension / as a liquid However, as temperature decreases they “fall out of suspension” and begin the crystallise The least soluble minerals crystalise first and fall to the bottom of the batholith Over time, as the magma cools, more minerals fall out of suspension causing layers to from This is called fractional crystallisation make up 95% of earths crust

• igneous intrusions are rocks formed from magma that cools and solidifies within the Earth’s crust. The intrusions produce pressurised superheated water at high temperatures that dissolves many minerals from the surrounding rocks. These mineral-rich solutions travel along fissures (sills and dykes) away from the igneous batholith, cooling as they do so. As they cool, dissolved minerals crystalise and come out of solution. They do this in order of their solubility: the least soluble crystallising first. • this process of fractional crystallisation starts with a mixture of minerals that could not have been exploited. Once the minerals become separated and deposited, soon after the batholith formed, later exploitation became possible. • metal ores that are deposited by hydrothermal processes include tin, copper, lead, silver. gold and arsenic. most soluble minerals volcanic \ I volcanic Dyke \ I ------------ sill \ I \ | batholith Least soluble minerals

Igneous processes and tectonic movements of crustal plates can alter existing rocks with high temperatures and pressure, without melting them producing metamorphic rocks. High temperatures and extreme pressure can change limestone to marble. Extreme pressure can change mudstone to slate. -Metamorphism requires heat and/or pressure -Highly metamorphosed rock found around a Batholith -The mineral Garnet only forms from this process

Sedimentary processes cause minerals to settle and build up to produce layers of deposited sediment. This deposition and subsequent cementation at the Earth’s surface and within bodies of water creates sedimentary rocks and minerals.

These include iron ore deposits such as haematite and magnetite. They are formed when dissolved irone compounds became oxidised by the oxygen released by photosynthesis, producing insoluble iron oxide deposits. This occurred manly between 2.5 and 1.8 billion years ago (the great oxygenation event.)

Biological processes are those where living organisms form mineral deposits. These processes often concentrate minerals that can be deposited in sedimentary rocks.

Limestone and chalk

coal

crude oil and natural gas

Microorganisms which contain calcium carbonate When compressed over millions of years they turn into… chalk

mined metal ores, non-metal minerals, fossil fuels, biogeochemical cycles (carbon, nitrogen, phosphorus), growth medium (soil).

• iron = buildings • aluminium = packaging foil • tin = solder, rust prevention • uranium = nuclear fuel for power station

The reserves include the amount of material that can be exploited now using existing technology under current economic conditions.

The amount of resource that is theoretically available for exploitation but not economically unless variability factors change (it includes all of the material that is theoretically available for exploitation) - it includes deposits that can be exploited now (the reserves) - also includes deposits that with a realistic increase in price or advancement in technology could be exploited in the future

As the linear purity of a deposit decreases, there is a logarithmic increase in the amount of the material that is included.