Class Notes- Unit 3 Flashcards
Where does evidence of the Earth’s interior come from?
- Astronomy
- Igneous Rocks
- Gravity
- Magnetism
- Seismology
- Heat Flow
- Experimental Petrology
What is Earth’s core composed of?
Fe and NI – metallic
Which is solid and which is liquid with Earth’s inner and outer core?
Inner: solid
Outer: liquid
What is the mantle composed of?
Fe, Mg, silicate
Is the mantle rocky and solid or molten and liquid?
rocky and solid
What do the asthenosphere and lithosphere compose?
mantle
How would one describe Earth’s crust?
complex – rocky
What is the Earth’s surface composed of?
- oceanic crust
2. continental crust (mountains, plain, and shields)
With plate tectonics, how is the Earth a “heat engine”?
The earth is a “heat engine”. It cools itself by conduction, radiation, and convection.
What is “iron catastrophe”?
Fe droplets sink and silicates rise (b/c lighter weight materials float up).
Is there any of Earth’s primitive crust left?
no
What is gravitational (planetary) differentiation?
Fe droplets sink and silicates rise. It is the process that formed Earth’s core, mantle, and primitive crust. Also known as the Iron Catastrophe.
What did the Iron catastrophe or gravitational differentiation require?
That the Earth be liquid – molten earth – for a long time.
What is the silicate mantle?
Minerals (chemical composition) made of silicon (Si) and oxygen (O) plus other elements.
How did the crust (as we know it today) form?
Not as a result of the iron catastrophe. It instead is the result of over 4 x 10^9 years of active geological processes – dynamic Earth.
