Rocks

Chapter 2 – RocksChapter 2 – Rocks

Rock typesRock types

Rocks have many different physical Rocks have many different physical characteristics. Some are different characteristics. Some are different colour, weight etc. We divide them colour, weight etc. We divide them into groups according to how they into groups according to how they were formed.were formed.

1. Igneous Rocks.1. Igneous Rocks. 2. Sedimentary Rocks.2. Sedimentary Rocks. 3. Metamorphic Rocks.3. Metamorphic Rocks.

Igneous RockIgneous Rock

These are rocks that were formed These are rocks that were formed when hot, molten volcanic material when hot, molten volcanic material (lava) cooled down and became (lava) cooled down and became solid.solid.

Examples – Granite and Basalt.Examples – Granite and Basalt.

Formation of Igneous RockFormation of Igneous Rock

Cooled down

under the Earth’s surface.

Cooled down on

the earth’s surface.

Magma Chamber

Vent

Igneous Rocks.Igneous Rocks. GraniteGranite..

Hard rock.Hard rock. Multi-coloured, pink, Multi-coloured, pink,

grey with crystals of grey with crystals of mica or quartz.mica or quartz.

Formed when magma Formed when magma cooled deep within the cooled deep within the earth;s crust.earth;s crust.

Cooled slowly so large Cooled slowly so large crystals formed.crystals formed.

Found in the Wicklow Found in the Wicklow Mountains.Mountains.

Basalt.Basalt. Heavy rock.Heavy rock. Black in colour.Black in colour. Formed when lava Formed when lava

cooled on the earth’s cooled on the earth’s surface.surface.

Cooled quickly so no Cooled quickly so no crystals formed.crystals formed.

Found at the Giant’s Found at the Giant’s Causeway.Causeway.

Granite (pink)Granite (pink)

Granite – (grey)Granite – (grey)

Basalt RockBasalt Rock

Basalt RockBasalt Rock

Basalt being formed at a Basalt being formed at a volcanovolcano

Basalt at the Giant’s Basalt at the Giant’s Causeway.Causeway.

Basalt at the Giant’s Basalt at the Giant’s Causeway.Causeway.

Granite in the Dublin Granite in the Dublin MountainsMountains

Igneous RocksIgneous Rocks AcrossAcross 4. Basalt is found at the Giant's...4. Basalt is found at the Giant's... 5. Molten Rock on the surface5. Molten Rock on the surface 6. formed under the ground6. formed under the ground

DownDown 1. Granite is formed in the Dublin...1. Granite is formed in the Dublin... 2. found on the surface2. found on the surface 3. Molten Rock Underground3. Molten Rock Underground

2007 Junior Cert Ordinary 2007 Junior Cert Ordinary LevelLevel

Sedimentary Rocks.Sedimentary Rocks.

These are rocks that were formed These are rocks that were formed from the compressed remains of from the compressed remains of plants, animals and other rocks.plants, animals and other rocks.

Examples – Limestone, Sandstone Examples – Limestone, Sandstone and Coal.and Coal.

Sedimentary Rocks.Sedimentary Rocks.

Sandstone.Sandstone. Coarse Rock.Coarse Rock. Brown/Red in colour.Brown/Red in colour. Formed when sand Formed when sand

grains were grains were compressed compressed together over time.together over time.

Found in the Found in the Macgillicuddy’s Macgillicuddy’s Reeks.Reeks.

Sedimentary rock – Sedimentary rock – Limestone.Limestone.

OriginOrigin – –

Made from the compressed remains Made from the compressed remains of fish and other sea creatures. of fish and other sea creatures. When they die their skeletons fall to When they die their skeletons fall to the sea floor where they become the sea floor where they become cemented together to form solid cemented together to form solid rock.rock.

Characteristics of Characteristics of Limestone.Limestone.

Laid down in horizontal layers or Laid down in horizontal layers or strata.strata. The division between the layers are called The division between the layers are called

bedding planesbedding planes.. Vertical joints called Vertical joints called jointsjoints occur in occur in

limestone.limestone. Limestone is Limestone is permeablepermeable which means which means

water can pass through it.water can pass through it. Contains many Contains many fossils.fossils. Can be Can be weatheredweathered easily. easily.

Limestone.Limestone.

Limestone.Limestone.

Strata.

Limestone Pavement – The Limestone Pavement – The Burren.Burren.

Clints.

Grikes.

Limestone – Fossils.Limestone – Fossils.

Limestone – Fossils.Limestone – Fossils.

Uses of Limestone.Uses of Limestone.

Cement for the building industry.Cement for the building industry. Headstones in graveyards.Headstones in graveyards. Blocks of limestone to make Blocks of limestone to make

buildings.buildings. Limestone chippings for road Limestone chippings for road

surfaces.surfaces. Ground up limestone is used by Ground up limestone is used by

farmers to fertilise the soil.farmers to fertilise the soil.

Uses of limestone.Uses of limestone.

Uses of limestone - GPOUses of limestone - GPO

2009 Higher Junior Cert 2009 Higher Junior Cert PaperPaper

Across2. S__________ rocks3. Preserved remains of life 5. Made from compressed sand 6. Layers in Sedimentary Rock

Down 1.Joints between Layers 4. Made from Compressed Remains of Sea Creatures

Metamorphic Rocks.Metamorphic Rocks.

These are rocks that were once These are rocks that were once Igneous or Sedimentary which Igneous or Sedimentary which changed due to great heat or changed due to great heat or pressure over time.pressure over time.

Examples – Marble and Quartzite.Examples – Marble and Quartzite.

Metamorphic Rocks.Metamorphic Rocks.

Marble.Marble. Hard rock with Hard rock with

crystals.crystals. Varies in colour – Varies in colour –

white, red , green white, red , green or black.or black.

Limestone changes Limestone changes into Marble.into Marble.

Quartzite.Quartzite. Hard rock.Hard rock. Light coloured.Light coloured. Found at the Hill of Found at the Hill of

Howth and the Howth and the Great Sugar Loaf.Great Sugar Loaf.

Sandstone changes Sandstone changes to Quartzite.to Quartzite.

Marble – white.Marble – white.

Marble – green.Marble – green.

Marble – fireplace.Marble – fireplace.

Across 1.M...rocks 3. Can Change rocks 4. A Type of metamorphic rock 5. This rock changes to Quartzite 6. Can change rocks Down 1.A type of metamorphic rock 2. One use for Marble

2011 Higher Level Paper2011 Higher Level Paper

Quick QuizQuick Quiz

Igneous rocks were formed from particles of other Igneous rocks were formed from particles of other rocksrocks

Metamorphic rocks are formed from metalMetamorphic rocks are formed from metal Basalt is an igneous rockBasalt is an igneous rock Fossils can often be found in LimestoneFossils can often be found in Limestone The Dublin Mountains were made from The Dublin Mountains were made from

Sedimentary rockSedimentary rock Crushed up limestone is used to make the Crushed up limestone is used to make the

concrete blocks in this classroomconcrete blocks in this classroom Quartzite is a sedimentary rockQuartzite is a sedimentary rock Diamonds are formed from lumps of coalDiamonds are formed from lumps of coal

2007 Higher Paper2007 Higher Paper

Extracting rocks.Extracting rocks.

Rocks provide us with many natural Rocks provide us with many natural resources – energy resources and resources – energy resources and building materials.building materials.

Rock based energy resources include Rock based energy resources include coal, oil, gas and peat.coal, oil, gas and peat.

These are extracted by mining and These are extracted by mining and quarrying.quarrying.

Oil mining.Oil mining.

Mined oil made into petrol.Mined oil made into petrol.

Coal Mining.Coal Mining.

Peat Harvesting.Peat Harvesting.

Quarrying.Quarrying.

Limestone Quarry in IrelandLimestone Quarry in Ireland

Name a use for...Name a use for...• Granite _____________________

• Basalt ______________________

• Sandstone __________________

• Limestone __________________

• Marble _____________________

• Quartzite ___________________

Quarries – for and againstQuarries – for and againstImagine a quarry is going to be built beside your home. Can you think of 3 reasons why people would be in favour of it and 3 reasons why they would be against it?

In Favour Against

2013 Junior Cert Paper2013 Junior Cert Paper