Download Why is there (almost) no oceanic crust older than 200 million years

EASC 100: EXAM1 (07):
Short Answer section:
1. (5) Why is there (almost) no oceanic crust older than 200 million years?
2. (3) What is the average thickness of oceanic crust?
3. (3) What is the average thickness (or range of thickness) of continental crust?
4. (4) Which planets are the ‘Gas Giants’ and what is the composition of their
atmospheres?
5. (3) What is the age of Earth?
6. (6) What are the two most abundant elements in the Earth’s crust and what are their
approximate concentrations?
7. (3) What are the next 6 most abundant elements in the Earth’s crust?
8. (2) I have a rock that contains significant amounts of feldspar. Is it felsic or mafic?
Please explain.
9. (7) MAFIC FAMILY:
A. Key minerals
B.
C.
D.
E.
F.
Color:
Silica content
Density
Temperature of melt
Viscosity of the magma
light
high
high
high
high
dark
low
low
low
low
light
high
high
high
high
dark
low
low
low
low
10. (7) FELSIC FAMILY:
G. Key minerals
H.
I.
J.
K.
L.
Color:
Silica content
Density
Temperature of melt
Viscosity of the magma
10. (9) Bowen’s Reaction Series:
1.__________________________
3.__________________________
5.__________________________
7.__________________________
9.__________________________
2._______________________
4._______________________
6._______________________
8._______________________
A) Olivine
B) Muscovite
C) Amphibole
D) Biotite
E) Sodium-rich Feldspar
F) Calcium-rich Feldspar
G) Pyroxene
H) Plagioclase
I) Quartz