O Level Environmental Management: Rocks and Minerals — Practice Questions

These are original questions written for Marlbridge, in the style and at the standard of the examination. They are not reproduced past-paper questions — examination boards hold copyright in their own papers. Use these alongside the official past papers available free from your board.

Related: Rocks and Minerals revision notes

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Section A

1. Name the three types of rock and describe how each forms. [6]

2. Give one example of each rock type and one use of each. [6]

Section B

3. Describe the rock cycle, naming the processes that convert each rock type into another. [6]

4. Compare open-cast (surface) mining with underground mining, giving two advantages and two disadvantages of each. [8]

5. Explain four environmental impacts of mineral extraction. [8]

6. Explain four strategies for reducing the environmental impact of mining and for restoring a worked-out site. [8]

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Section C

7. Distinguish between a mineral and a reserve. [2]

8. A country reports copper ore reserves of 600 million tonnes and extracts 12 million tonnes a year. A newspaper claims “reserves will last exactly 50 years.” Show this calculation, then explain why the claim is unreliable, giving two reasons. [3]

9. Adit mining is a third extraction method, alongside open-cast and underground (shaft) mining. Describe what it involves and state one situation in which it is used. [2]

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Answers

1. Igneous — formed when molten magma or lava cools and solidifies; slow cooling underground gives large crystals, rapid cooling at the surface gives small ones [1] [1]. Sedimentary — formed when sediment is deposited in layers, then compacted and cemented over long periods; may contain fossils [1] [1]. Metamorphic — formed when existing rock is altered by intense heat and/or pressure without melting, which changes its texture and mineral structure [1] [1].

2. Igneous — granite, used for building stone and kerbstones [1] [1]. Sedimentary — limestone, used to make cement and as a flux in iron smelting [1] [1]. Metamorphic — marble, used for sculpture and decorative flooring; or slate for roofing [1] [1].

3. Weathering and erosion break down exposed rock into sediment, which is transported and deposited [1]. Compaction and cementation turn the sediment into sedimentary rock [1]. Burial under heat and pressure converts sedimentary or igneous rock into metamorphic rock [1] [1]. Further heating causes melting into magma [1], which on cooling and crystallising forms igneous rock, and uplift returns rock to the surface to begin the cycle again [1].

4. Open-cast advantages: it is cheaper and faster, since no shafts or tunnels are needed [1]; it is far safer for workers, with no risk of roof collapse or gas [1]; a higher proportion of the ore can be recovered. Open-cast disadvantages: it destroys a very large surface area, removing vegetation, habitat and topsoil [1]; it produces enormous visual scarring, dust and noise affecting nearby communities [1]. Underground advantages: it has a much smaller surface footprint, so land use above is largely unaffected [1]; it can reach deep deposits that open-cast cannot economically access [1]. Underground disadvantages: it is far more expensive and slower [1]; it is dangerous — roof falls, flooding, gas and dust diseases — and subsidence can damage buildings at the surface [1].

5. Any four, 2 marks each: habitat destruction and biodiversity loss, as vegetation and soil are stripped over large areas [1] [1]; water pollution — acid mine drainage and heavy metals such as mercury and cyanide from processing enter rivers and groundwater, killing aquatic life and contaminating drinking water [1] [1]; air pollution — dust from blasting and haulage, and sulfur dioxide from smelting, causing respiratory illness and acid rain [1] [1]; land degradation and soil erosion, with spoil heaps and tailings dams that may fail catastrophically [1] [1]; noise and visual pollution affecting quality of life and tourism [1] [1]; deforestation where mines are opened in forested regions, releasing stored carbon [1] [1].

6. Any four, 2 marks each: environmental impact assessment before permission is granted, so damaging schemes are refused or modified [1] [1]; progressive restoration — replacing topsoil and replanting native species as sections are worked out, rather than waiting until closure [1] [1]; treating waste water and containing tailings in properly engineered and monitored dams before discharge [1] [1]; reclaiming the site for a new use — flooding a pit to create a lake for recreation and wildlife, or landscaping for agriculture, forestry or building land [1] [1]; dust suppression by spraying and by covering conveyors, and screening with earth banks and tree belts to reduce noise and visual impact [1] [1]; recycling metals so that less ore needs to be extracted in the first place [1] [1].

7. A mineral is a substance obtained by mining [1]. A reserve is a known deposit not yet mined that could be extracted in future, counted only once extraction is economically viable [1].

8. 600 ÷ 12 = 50 years [1]. Unreliable because: the extraction rate is unlikely to stay constant — demand usually grows over time [1]; and/or continued exploration may discover new deposits, or rising prices may make lower-grade ore economically viable, both of which would increase the reserve figure [1].

9. Adit mining drives a near-horizontal passage into a hillside to reach a seam [1]. It is used where a deposit is exposed on a sloping hillside, rather than lying flat near the surface or buried deep underground [1].

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Where marks are usually lost

• Saying metamorphic rock forms by melting.
• Giving advantages of open-cast mining without acknowledging the surface destruction.
• Listing impacts without explaining the mechanism or the harm.
• Describing restoration only as “planting trees”.
• Treating a reserves-divided-by-extraction-rate calculation as a reliable prediction, without stating what it assumes.
• Forgetting adit mining as a distinct third method, alongside open-cast and underground mining.