Chapter 1: Rocks and mineral extraction

Igneous rocks

Igneous rocks

Rocks that are formed by the solidification of molten magma or lava.

Intrusive ignenous rock

Magma cools beneath the surface

Extrusive igneous rock

Magma comes out as lava and cools on the surface

Give two examples of igneous rocks.

Granite and Obsidian

Give two properties of igneous rocks.

1. Contains crystals

2. High density

Sedimentary rock

Rocks that are formed from sediments

Give two examples of sedimentary rock.

Limestone and Sandstone

Give two properties of sedimentary rock.

1. Soft and break apart easily

2. May contain remains of living organisms

Metamorphic rocks

Rocks that are formed from high pressures or temperatures

Give two examples of metamorphic rocks.

Gneiss and Quartzite

Weathering

The breaking down of minerals or dissolving of rocks in the Earth’s surface

Erosion

The process of wearing away and moving of rocks, soil, or other materials on the Earth's surface by natural forces like wind, water, or ice.

Mineral

A solid, hard natural substance

Ore

A rock containing high amounts of minerals

Give two methods of mining.

Subsurface and surface mining

Subsurface mining

Mining involves sinking a vertical shaft underground to the rocks containing minerals and building a horizontal tunnel down to the mineral layers and loose rock from the mines is transported to the surface where the minerals get transported away. This type of mining is used when the ore deposits are below the Earth’s surface.

Surface mining

Mining that involves the removal of vegetation, and explosion of rocks, where the machines are used to remove loose rocks, and the rock being transported by trucks or railway wagons

Give three types of surface mining.

• Open pit mining

• Quarrying

• Strip mining

Identify some uses of different rocks.

Sand → Makes glass

Chalk→ Manufacturing cement

Gravel → Makes concrete

Granite → Used for construction

Identify an advantage of subsurface mining

Lesser pollution

Identify the disadvantages of subsurface mining.

• More expensive

• More dangerous to miners

• Tunnel collapses

Identify an advantage of surface mining

Less expensive

Identify the disadvantages of surface mining

• Visual pollution

• Noise pollution

• Destruction of habitats

• People have higher risks of getting infectious diseases

Identify three ways of conserving the environment damaged by mining.

• Landfilling

• Landscaping

• Reclamation

Landfilling

The dumping of waste in an area.

Identify the impacts of landfilling.

• Cheap and easy way to dispose waste

• Causes pollution

• Affects nearby communities with polluted water and higher risks to diseases such as cholera

Landscaping

Land is made to look like a natural landscape to make it look as if the land was not disturbed by mining

Reclamation

The land can be reclaimed by from mining to be used for farming