Introduction (Chapter 1) Flashcards
True or False: Is melt the same as magma?
False. Melt is apart of the magma (Diagram 1)
Why are igneous processes most dominant in contributing to a differentiated planet?
They are responsible for the division of the crust from the mantle.
What are the two main silicate groups of Earth’s mantle? (think elements)
Mg and Fe minerals
What 3 common minerals can be found in Earth’s mantle?
Olivine, Orthopyroxene, and Clinopyroxene
True or False: The asthenosphere is completely solid.
False. The asthenosphere isn’t completely solid. It is unstable and ductile.
Name the 3 major units of Earth’s interior.
The crust, mantle, and core
What kind of rocks make-up the majority of oceanic crust?
Basaltic Rocks
What kind of rocks make-up the upper level of the continental crust?
Felsic rocks (granodioritic)
What kind of rocks make-up the lower level of the continental crust?
Same as oceanic crust (basaltic rocks)
What makes up Earth’s core?
Fe-rich metallic alloys with minor S, Si, Ni, O
Pressure _____ with depth
Increases
Temperature ______ with depth
Increases
Thermal gradient ______ with depth
Varies
Thermal gradient in oceanic lithosphere is ______ than that in the continental lithosphere
Higher
What is an adiabatic geotherm?
It is the steepening of the geothermal profile in the asthenosphere due to convection. (Diagram 2)
The melting of rocks depends on what three components?
Temperature, Pressure, and Composition
What are the three mechanisms that lead to melting?
1) Increasing temperature (Adiabatic upwelling)
2) Decreasing pressure (Adiabatic upwelling)
3) Lowering solidus (addition of fluids)
What is the solidus?
Start melting
What is the liquidus?
Complete melting
True or False: Global distribution of heat flow is directly related to plate tectonics.
True
Plate tectonics are driven by what?
Convectional cells
What are the three mechanisms of magma generation?
1) Mid-ocean ridge basalts
2) Ocean island basalts
3) Island arc basalts
(Diagram 3)
