Reserves and resource — AQA A-Level Environmental Science

The study of mineral resources and reserves forms a core foundation of environmental geology and resource management within AQA A-Level Environmental Science. It examines the finite physical endowment of mineral deposits in the Earth's crust versus the fraction society can practically, legally, and profitably exploit at any given time.

Understanding this distinction is vital for assessing long-term global sustainability, resource depletion trajectories, and geopolitical supply vulnerabilities. It links directly with technological extraction innovations, market economics, and the environmental impacts associated with processing increasingly low-grade ores.

• →Total Resource: All deposits of a mineral that exist in the Earth's crust, including both identified deposits and undiscovered, speculative accumulations.
• →Reserves: The specific subset of identified resources that can be extracted legally, technologically, and economically under current market conditions.
• →McKelvey Box: A two-dimensional classification matrix showing geological certainty on the horizontal axis and economic feasibility on the vertical axis.
• →Dynamic Boundary: The non-static nature of reserves, which expand or contract based on market commodity prices, transport infrastructure, and technological innovation.
• →Cut-off Ore Grade: The minimum concentration of a mineral within rock that can be extracted at a financial break-even or profit level.

• Identifies reserves as the portion of a resource recoverable with existing technology.
• States that reserves must be economically viable under current conditions.
• Recognises that reserves are a subset of the total resource.
• Explains that changing technology or price can shift material between resource and reserve.

• 💡Underline both filters in the definition: existing technology and current economic conditions.
• 💡Use a price-change example to show why reserves are dynamic rather than fixed.
• 💡Check that your chosen option keeps reserves inside the larger resource.
• 💡Always use the term 'economically and technologically viable' when defining a reserve to secure all available marks.
• 💡Reference the McKelvey box by name when describing changes in resource status to demonstrate top-band subject mastery.
• 💡Connect resource-to-reserve shifts to real environmental consequences; exploiting lower-grade reserves generates exponentially larger volumes of mine spoil, overburden, and toxic tailings.

• Treats reserves and resources as identical terms; keep reserves as the technologically and economically recoverable subset.
• Assumes reserves are fixed forever; recognise that price and technology changes move material in and out of reserve.
• Ignores the economic condition and counts any technically extractable material as a reserve; require current profitability too.
• Believing that reserves run out permanently: Students often assume when reserves hit low levels, the physical mineral is exhausted. In reality, as prices rise, sub-economic resources are reclassified into reserves.
• Confusing cut-off ore grade with mineral abundance: A low cut-off grade indicates superior extraction technology or higher market prices, not a lack of surrounding mineral.
• Assuming all identified deposits are reserves: High-grade deposits located beneath national parks or ultra-deep marine environments may be legally or technically inaccessible, remaining resources rather than reserves.

1. 1Day 1-2: Master the exact definitions of resource, reserve, hypothetical resource, and speculative resource, creating visual flashcards.
2. 2Day 3-5: Practise drawing and labelling the McKelvey box from memory, plotting hypothetical shifts caused by price shocks and new mining patents.
3. 3Day 6-8: Work through calculation problems determining cut-off ore grades, reserve lifetimes (Reserve-to-Production ratios), and ore recovery percentages.
4. 4Day 9-10: Review past exam paper 6-mark and 9-mark evaluation questions focusing on the environmental costs of lowering cut-off ore grades.

• 📋Definitional and Distinction Questions (2-3 marks): Requiring precise textbook distinctions between resources and reserves.
• 📋Diagram Labelling / McKelvey Box Interpretation (2-4 marks): Annotating axes, identifying categories, or drawing arrows indicating technological changes.
• 📋Data Analysis and Calculations (3-5 marks): Calculating pure mineral yield from ore grade or projecting reserve lifespans using annual consumption rates.
• 📋Evaluative Extended Prose (6-9 marks): Assessing how economic or technological shifts affect the viability of exploiting low-grade mineral deposits.