Rocks Flashcards
What are Rocks?
As you stand on the surface of the earth, underneath your feet is rock.
Rocks can differ in their colour, texture, hardness and mineral content.
They can be made of a single mineral or many minerals compressed together.
Minerals are inorganic materials, meaning that they do not come from an animal or plant.
Rocks make up our landscape and provide us with many essential resources
The Rock Cycle
Based on their origin or how they were formed, rocks are divided into 3 groups : igneous, sedimentary and metamorphic.
Rocks are constantly changing and going through a cycle
How are igneous rocks formed?
What are igneous rocks?
Give two examples
Magma comes up from the mantle. Some of it gets stuck underground and cools slowly. This slow-cooling magma turns into intrusive igneous rock. The magma that reaches the surface flows out and cools quickly in the air, forming extrusive igneous rock.
Examples of these rocks are granite and basalt.
How are sedimentary rocks formed?
What are sedimentary rocks?
Give two examples
Rocks on the surface of the earth are worn down over time. Some broken pieces are dropped in layers on the sea floor. Here they become pressed and cemented together, mixing with dead sea creatures to form sedimentary rock.
Examples: Sandstone and limestone
How are metamorphic rocks formed?
What are metamorphic rocks?
Give two examples
Metamorphic rocks are formed when igneous or sedimentary rocks are put under great heat or pressure.
This changes the rock into a new, harder rock.
Examples: Marble and quartzite
Igneous Rocks
examples:
Granite - minerals in magma form large crystals, these crystals include quartz, mica and feldspar
Basalt - basalt has very small crystals that can only be seen using a microscope
Basalt can be found in the Giants Causeway
Sedimentary Rocks
Examples:
Sandstone - sandstone is typically brown to red in colour. Sandstone can be used to make tiles or monuments and can be found in the Macgillycuddy’s Reeks, Co.Kerry
Limestone - limestone is a permeable rock which means that water can pass through it.
Limestone is also soluble, meaning that it dissolves in water
Metamorphic Rock
Examples:
Marble - marble is white but it can also be green red or black. Marble has a hard texture and is used for making headstones, fireplaces, monuments and tiles.
Quartzite - quartzite is grey to white colour and extremely hard in texture. It is used in the surfacing of roads, in watches and glass.
It can be found in county Wicklow and Mayo
Human interaction with Rocks
- Oil, gas, coal and turf can be used as energy and heat sources
- Gold, diamonds, metals and precious stones are used in jewellery
- Gravel, stone and sand are used as building materials
- Metal ores such as copper and lead are used in pipes and batteries
What is drilling?
Give environmental and economic impacts
Drilling - the process of boring down into the earths crust to extract oil or gas.
Oil and gas are used as fuel sources in cars, homes and industry
Environmental impact: onshore and offshore oil spills can cause damage to the local environment. Birds and animals can ingest the oil. This can cause damage to the animal or even death.
Economic: the Corrib Oil and Gas Field project off the Maho coast has had investment of almost €4.3 billion from three companies. At full production, Corrib has the potential to provide 60% of Ireland’s gas need and expected to supply fuel for up to 20 years
What is Quarrying?
Give environmental and economic impacts
Quarrying - this is the process of removing rock, sand, gravel or minerals from the ground.
Also known as open-cast mining, quarrying also happens near the surface of the earth. These materials extracted are used by the construction industry to build roads and buildings.
Environmental: Large quantities of dust are created which can cause air pollution. It also is also very noisy creating noise pollution.
Economic: quarrying has an important impact on the Irish economy as there are approx. 10,000 people employed in quarrying. Quarrying produces €1 billion for the Irish economy
What is shaft mining?
Give environmental and economic impacts
Shaft Mining - this is the process of drilling vertically into the earth to gain access to minerals beneath the surface: coal, lead and zinc can be found this way
Environmental impact: underground mining allows companies to dig for coal, lead or zinc deeper in the grounds
Economic impacts: the Tara lead and zinc mines in county Meath support 739 jobs directly and many more indirectly. The company pays €38 million in taxes annually
