3.1 - Rock cycle
A _____ is a naturally formed _______ that is usually made up of _____ or more ____________ in different proportions.
A _Rock is a naturally formed _solid that is usually made up of _two_ or more _minerals_in different proportions.
What is the name given to the processes that form, break down and reform rocks?
The rock cycle
What's the difference between magma and lava?
Magma doesn't reach Earth's surface, while lava does
What two things do we use to classify and identify igneous rocks?
1) Texture
2) Composition / Silica content
What are the three main rock types?
Igneous, metamorphic and sedimentary
What lies beneath the Earth's thin layer of surface features?
Solid and molten rock
What type of rock forms when heat and pressure changes older rocks?
Metamorphic rocks
How do intrusive igneous rocks form?
Magma cools down within the Earth
What determines the texture of an igneous rock?
How quickly the molten rock cools down
What igneous rock is Jeju mostly made of?
Basalt (and Trachyte)
Give an example of a rock which contains no minerals.
Obsidian, coal
How is igneous rock formed?
Molten rock cools and becomes solid
How do intrusive rocks reach the surface?
The forces inside the Earth push them up to the surface
What forms from the lava that flows out of a volcano or crack?
Extrusive igneous rock
What is Mr. Phillip's favorite igneous rock?
(Hint, its a light colored intrusive rock)
Granite
On what timescale do rocks change?
Thousands to millions of years
What percentage of rocks found at the surface are sedimentary rocks?
75%
What can be concluded about a light colored igneous rock?
It has a high silica content
Why do intrusive igneous landforms tend to be long-lasting landforms?
They are harder than the other surronding rock
What is Ship Rock an example of?
An intrusive igneous rock feature
When we look at the crust as a whole, what percentage of rocks are igneous or metamorphic?
95%
Why are sedimentary rocks only commonly found at the surface?
The processes which make sedimentary rocks only occur at the surface
A lava that is _________ will create a shield volcano with gently sloping sides or spread out into thin sheets over great distances due to the lava flowing easily.
Low in silica
A lava that is ___________ in silica will create a cone volcano with step sides which will have explosive eruptions.
High in silica
How could an igneous rock become a sedimentary rock?
If intrusive igneous - Uplifted, eroded and weathered, sediment transported and deposited, compressed by layers to form rock
If extrusive - eroded and weathered, sediment transported and deposited, compressed by layers to form rock