Rocks Flashcards
Name the 3 rock groups
Igneous
Sedimentary
Metamorphic
How are Igneous rocks formed
As a result of volcanic activity. Hot molten magma cools quickly into solid rock on the earths surface or deep underground
How are sedimentary rocks formed
From particles of rocks, dead plants and animals. They were deposited on the bed of the sea or lakes and built up over time to be compressed into layers of solid rock.
How are Metamorphic rocks formed
Formed from rocks that already exist. When igneous or sedimentary rocks are changed into harder rocks by great heat or pressure
Name an example of igneous rocks
Basalt
How is basalt formed
When lava from a volcano cools very quickly on the earths surface forming tiny crystals. It is black in colour and shaped like a hexagon
Name an example of basalt rock
Giants causeway
Name an example of sedimentary rocks
Limestone
Name an example of where limestone is found
Burren, co. Clare
What is limestone used for
Making monuments and buildings
Name an example of metamorphic rocks
Quartzite
Describe quartzite
Is an extremely hard rock mainly made from quartz.it varies in colour from grey to white. It was made from sandstone but was changed by great heat and pressure
Name an example of quartzite rock
Sugerloaf
What is quartzite used for
Road chipping, sandpaper and watches
Denudation
Is the process of wearing away rock or soil by weathering and erosion
Name the 2 types of weathering
Mechanical
Chemical
Mechanical weathering
Breaks rocks into smaller pieces
Chemical weathering
dissolves rocks
Name an example of chemical weathering
Carbonation
How does carbonation occur
When rainwater mixes with carbon dioxide in the atmosphere forming a weak carbonic acid. This acid reacts with calcium carbonate in the limestone, cashes for the rock to slowly dissolve.
Karst landscapes
Areas of exposed limestone
Cavern
When a cave is enlarged to a chamber
How are stalactites formed
- When water containing calcium carbonate seeps through the rock, some drops hang from the roof of the cave for awhile.
- some of the water evaporates leaving behind tiny deposits of calcium carbonate.
- these droplets build up over thousand of years to form stalactites
How are stalagmites formed
- When the droplets of water fall to the floor and evaporate, they also deposit some calcium carbonate.
- these build up over time to form stalagmites
