Chapter 3: Rocks

Question 1

Rocks are divided into three groups

Answer 1

Igneous rocks
Sendimentary rocks
Metamorphic rocks

Question 2

igneous rocks

Answer 2

Igneous rocks are formed as a result of volcanic activity. When hot molten magma escapes from the mantle it cools and hardens. If it reaches the surface as lava, it cools and solidfies quickly whereas the magma inside the crust cools more slowly

Question 3

Sedimentary rocks

Answer 3

Sedimentary rocks are formed from particles of other rocks, as well as dead plants and animals. These sediments are depoisted on sea and lake beds as well as on land. Layers of this material build up over time and are compressed and cemented, creating solid rock.

Question 4

Metamorphic rocks

Answer 4

Metamorphic rocks are formed from rocks that already exist. They form when igneous or sedimentary rocks are changed into new, harder rocks by great heat or pressure or sometimes both

Question 5

Examples of igneous rocks

Answer 5

Basalt

Granite

Question 6

Examples of sedimentary rocks

Answer 6

Limestone

Sandstone

Question 7

Example of metamorphic rocks

Answer 7

Marble

Quartzite

Question 8

Basalt

Answer 8

Colour: grey/black
Formation: Basalt is an extrusive rock. It is formed when lava spreads out over the surface of the Earth’s crust due to volcanic activity. It then cools and hardens. Basalt has tiny crystals which cannot be seen without the use of a microscope. This is because the lava cooled and hardened very quickly in the open air when it reached the surface
Example: The Giant’s Causeway eg: Antrim

Question 9

Limestone

Answer 9

Colour: grey
Formation: The limestone in Ireland was formed about 350 million years ago when Ireland was located close to the equator. Limestone is made from particles of shells and the remains of skeltons of sea creatures. When these particles sink to the seabed they are called sediment. The sediment piled up at the bottom of a warm, shallow sea over millions of years. The weight of the upper layers of sediment compressed and cemented the lower layers of sediment into strata (layers) of solid rock
Example: Burren Co. Claire

Question 10

Marble

Answer 10

Colour: white/red/green/black
Formation: Marble is formed when limestone is put under great heat or pressure due to plate movement or when molten magma comes in contact with limestone. It is a very hard rock that can vary in colour.
Example: Co. Antrim (white), Co. Cork (red), Co. Galway (green) and Co Kilkenny (black)

Question 11

Shaft Mining

Answer 11

The process of extracting coal from within the Earth’s crust is called shaft mining. Vertical wells are drilled and a shaft is constructed.

Question 12

How to gather oil and gas

Answer 12

Oil and gas are extracted from rock by drilling and pumping. This process involves drilling deep into the Earth’s crust and pumping the oil and gas to the surface.

Question 13

Quarrying

Answer 13

Extracting rock from the Earths surface. Large machinary is used to cut rock out of the crust, or explosives are used to break rock away from the crust.

Question 14

Positive impact of mining and quarrying

Answer 14

Employment
Provides materials, construction and energy
Raw materials, copper, steel, iron and glass

Question 15

Negative impacts of mining and quarrying

Answer 15

Pollution
Eyesore, they look pretty
Traffic conjection