How do Earth and environmental processes form renewable and non-renewable resources?
Explain how Earth processes form renewable and non-renewable mineral and energy resources
A focused answer to the WACE Year 12 Earth and Environmental Science dot point on resource formation. Covers how the geosphere, hydrosphere, atmosphere and biosphere interact to form mineral, fossil fuel and renewable energy resources, with Australian examples.
Reviewed by: AI editorial process; not yet individually human-reviewed
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What this dot point is asking
SCSA wants you to classify resources and explain the Earth processes that form them. A strong answer links each resource to the spheres involved and to the rate of formation, because rate is what separates renewable from non-renewable.
Classifying resources by rate of replenishment
A non-renewable resource forms so slowly, over millions of years, that it cannot be replaced within a human lifetime. Once extracted it is depleted. A renewable resource is replenished by continuing natural processes on a timescale of days to decades, so it can be used indefinitely if extraction does not exceed the replenishment rate.
The key idea SCSA emphasises is that resources are concentrations of matter and energy produced by interactions of Earth systems. A useful deposit exists only where a process has concentrated a material far above its average crustal abundance.
Formation of mineral resources
Metallic mineral deposits form where geological processes concentrate metals.
- Magmatic processes: as magma cools and crystallises, dense minerals settle and concentrate. Nickel, chromium and platinum deposits form this way.
- Hydrothermal processes: hot, mineral-rich water moves through fractures and deposits metals as it cools. Many gold and copper deposits, including those of the Kalgoorlie goldfields in Western Australia, are hydrothermal.
- Sedimentary and weathering processes: chemical weathering can leave behind enriched residues. The vast banded iron formations of the Pilbara formed when oxygen from early photosynthesis reacted with dissolved iron in ancient oceans, precipitating iron oxides over hundreds of millions of years.
Bauxite (aluminium ore) in the Darling Range near Perth formed by intense tropical weathering that leached away soluble elements and left aluminium-rich residue. This shows the biosphere, atmosphere and hydrosphere all shaping a geosphere resource.
Formation of fossil fuel resources
Fossil fuels are non-renewable energy resources formed from the buried remains of organisms.
- Coal forms from plant matter that accumulated in swamps, was buried, and was compressed and heated over millions of years, progressing from peat to lignite to bituminous coal.
- Oil and natural gas form from marine microorganisms whose remains were buried in fine sediment. Heat and pressure transformed the organic matter into hydrocarbons, which then migrated and collected in porous reservoir rocks beneath impermeable cap rocks. The North West Shelf gas fields off Western Australia are a major example.
Fossil fuels store ancient solar energy captured by photosynthesis, so their formation also links biosphere and geosphere.
Formation of renewable energy resources
Renewable resources are driven by continuous external and internal energy flows.
- Solar energy arrives constantly from the Sun.
- Wind results from uneven solar heating of the atmosphere.
- Hydro depends on the water cycle, itself solar-powered, lifting water that then flows downhill.
- Biomass stores recent solar energy in living material.
- Geothermal taps heat from Earth's interior.
Because these flows are continuous, the resources are renewable, but they are not unlimited at any moment: output depends on conditions such as sunlight, wind speed and rainfall.