The Earth's Layers Flashcards
What three layers is the inferior of the earth divided into
Crust, mantle and core
What is the core made up of
Dense rocks containing iron and nickel alloys
What is the core divided up into
A solid inner core and a molten outer one
What temperatures does the core reach
Over 5,000•c
What is the mantle made up of
Molten and semi molten rocks containing lighter elements (silicon, oxygen, aluminium, potassium and sodium)
How thick is the crust beneath the oceans
6-10 km thick
How thick is the crust beneath the continents
Up to 70km thick
What is the crust and the upper mantle divided into
The lithosphere and the asthenosphere
What is the lithosphere
- consists of the crust and the rigid upper section of the mantle
- 80-90 km thick
What is the lithosphere divided up into
Seven larger plates and several smaller ones
What are the two categories that plates are divided up into
Oceanic and continental- depending on the type of material from which they are made
What is below the lithosphere
The semi-molten asthenosphere, on which the plates float and move
How thick is the continental crust
30-70 km thick
How thick is the oceanic crust
6-10 km thick
How old is the continental crust
Over 1,500 million years
