1.2 Extraction of Rocks and Minerals from the Earth

IGCSE Environmental Management (0680)

2026 📋 Syllabus Objectives

By the end of this subtopic, you should be able to:

  1. Describe the methods of extracting rocks and minerals from the Earth — including surface mining and subsurface mining.
  2. Discuss the factors that affect the decision to extract rocks and minerals.
  3. Understand key terms including: opencast / open-pit / open-cut / strip mining; deep mining / shaft mining; exploration; geology; accessibility; environmental impact assessment; supply and demand.

📖 Main Content

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Why Do We Extract Rocks and Minerals?

Minerals and rocks are incredibly important in our daily lives. Here's why we need them:

  • Coal and oil give us energy and are used to make chemicals and fuels.
  • Metallic ores (rocks that contain enough metal to be worth mining) are used to make metals and alloys — the materials that go into computers, phones, cars, and countless other products.
  • The global demand for minerals is increasing — meaning more and more countries and industries need these resources every year.

Because of this growing demand, humans need to find and extract (remove) minerals from the Earth efficiently and safely.

Finding Minerals — Exploration and Prospecting

Before any mining can take place, companies must first find where the minerals are. This process is called exploration (searching for mineral deposits).

What is Prospecting?

Prospecting is the process of searching carefully for mineral deposits. In the past, people simply looked at rocks on the surface. Today, much more advanced methods are used.

Methods of Finding Minerals:

1. Remote Sensing (Satellites and Aerial Photography)

  • Remote sensing means gathering information about the Earth's surface from above — using aircraft or satellites — without physically touching the ground.
  • Minerals that have been weathered (broken down) at the surface produce mineral oxides (compounds formed when minerals react with oxygen). These give off a unique pattern of radiation that satellites can detect.
  • A satellite records this radiation pattern and sends the data to a computer for analysis.
  • This system works in all weather conditions, even through thick clouds and at night.
  • Aerial photography involves aircraft taking many overlapping photographs of the land below. These overlapping images can be used to build a 3D picture of the landscape and spot signs of mineral deposits.
  • Because satellites cover huge areas quickly and cheaply, large regions can be geologically mapped (mapped according to their rock and mineral types) in a short time.
  • Once a promising area is identified, geologists (scientists who study rocks) visit the location on the ground to confirm what the satellite detected.

2. Ground Surveys (Field Work)

  • Geologists collect samples of rock, soil, or river sediment from the area.
  • These samples are sent to a laboratory for geochemical analysis — meaning scientists identify which chemicals and minerals are in the samples.
  • Sample points are chosen by placing a grid over a map of the area, so that samples are taken in an organised, even pattern.
  • The exact location of each sample point is found using GPS (Global Positioning System), a satellite-based system that tells you your exact location on Earth.

3. Geophysics (Seismic Surveys)

  • Geophysics involves studying the physical properties of rocks.
  • Scientists use a vibrator truck to send seismic waves (vibrations, similar to mini-earthquakes) down into the ground.
  • These waves travel through different rock layers and bounce back (reflect) to sensors placed on the surface.
  • Different rocks and minerals reflect waves in different patterns, so scientists can figure out what is underground by studying these reflections.
  • Sometimes explosives are used instead of a vibrator truck to create the waves, but this is more dangerous.

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