5 Rocks Flashcards
Oirigin
Where and how rocks were created
What is mineral content of rocks
Rocks are composed of one or more minerals such as calcite quartz and gypsum
What is texture
How rough or smooth the rock feels
What is hardness
The rocks resistance to weathering and erosion
What is density
Amount of rock compared to amount of space it takes up (air fills gaps in porous rocks sl tbeyre less dense)
Rock shape
How the tocks were laid down
E.g Basalt in hexagonal shapes Giants Causeway
Compaction
Sediments are squeezed together by the weight of overlying lauers including water
Cementation
Water evaporates from dissolved minerals, creating crystals that glue sediments together
Rock cycle
Cooling of magma/lava into solid rock
Melting of rock into magma (during subduction)
Breaking down of rock into sediments by the elements of weathering and erosion
Reformation if solid rock through lithification
Changing if a rocks structure by heat and pressure
What are the three rock groups
Igneous
Sedimentary
Metamorphic
What are plutonic (intrusive) rocks
Rocks formed deep beneath the earths surface
Eg. Granite
What are volcanic (extrusive) rocks
Rocks formed on the earths surface
E.g Basalt Giants Causeway
Whats another word for extrusive rocks
Volcanic rocks
Whats another word for intrusive rocks
Plutonic
2 types of igneous rock and example
Basalt- Antrim Derry Plateau
Granite- Wicklow Mountains
2 types of sedimentary rock + exapmle
Limestone- The Burren Clare
Sandstone-Machillycuddys reeks
2 types of metamorphic rocks + example
Marble-Connemara
Quartzite-Hill of Howth Dublin
When can igneous rock be classified as acidic
When it has a silica content of more than 55%
List three minerals found in granite
Feldspar
Quartz
Mica
At what type of boundary is basalt formed
Divergent
What colour is basalt
Black/dark grey
What colour is granite
Typically grey
Can vary in colour depending on proportions of minerals in the rock
What are organic sedimentaty tocks
Formed from decayed living things and plants/vegetation
What are inorganic sedimentary rocks
Formed from the broken down sediments of other rocks
Where can limestone be found
Burren Co Clare
What is the most common rock formed in Ireland
Limestone
Where cab sandstone be found
Macgillycuddys reeks
What cokour is sandstone
Reddish brown, due to presence of iron oxide
