Download Geol 15 Mid Term I 200 Points Name: Date: The following five

Geol 15 Mid Term I 200 Points
Name: ________________________________________ Date: ______________
The following five questions refer to the faults in figure below.
1. (5 pts) Which of the above choices is a true reverse fault?
2. (5 pts) Which of the above choices is a true normal fault?
a. A b. B c. C d. D e. E f. F g. G
a. A b. B c. C d. D e. E f. F g. G
3. (5 pts) Which is a blind thrust fault? a. A b. B c. C d. D e. E f. F g. G
4. (5 pts) Which of the following fault(s) would result from stretching forces?
a. a&b
b. b&c
c. c
d. d
e. none of these choices
5. (5 pts) Which of the following pairs of faults are the results of compressive stresses?
a. a&b
b. b&c
c. d&e d. none of these
6. (5 pts) When you squeeze the earth it generally becomes __________.
a. thinner
b. thicker
c. sickerd. slicker
7. (5 pts) If you stretch the earth it generally becomes __________.
a. thinner
b. thicker
c. both
d. none of these
8. (5 pts) Name the one feature not found at a divergent boundary.
a. a rift valley
b. high heat flow c. shallow earthquakes
d. a trench
9. (5 pts) Magnetic stripes are areas of the oceanic crust that retain the magnetic field at the time of
their formation along oceanic ridges, usually display symmetric bands on either side of the ridge, and
the magnetic anomalies are older as one gets farther from the ridge.
a. True b. False
Geol 15 Mid Term I 200 Points
10. (5 pts) Which of the following is the correct order of the layers of the Earth from inside to outside?
A) inner core, outer core, crust, mantle
B) inner core, mantle, outer core, crust
C) crust, inner core, outer core, mantle
D) inner core, outer core, mantle, crust
E) mantle, inner core, crust, outer core
11. (5 pts) Where are earthquakes generally found?
A) convergent boundaries
B) divergent boundaries
C) Transform Fault boundaries
D) Hot spots
E) Earthquakes are found on all of the above locations
12. (5 pts) Which of the following is true about the Mid-Atlantic Ridge?
A) It is in the middle of the ocean
B) It is a divergent boundary where tectonic plates move apart
C) It is a place where new lithosphere is created
D) It is a site of deep sea volcanoes and mountains
E) All of the above are true about the Mid-Atlantic Ridge
13. (5 pts) The energy for Plate Tectonics comes from
A) the magnetic field of the earth
B) heat from the sun
C) gravity between the earth and moon
D) ocean currents
E) heat from the earth's core
14. (5 pts) The Himalayas are associated with which of the following plate boundaries?
A) Ocean-continental convergence
B) Ocean-ocean convergence
C) Continent-continent convergence
D) Divergent
E) Transform Fault
15. (5 pts) If you wanted to draw the boundaries of plates on a globe, which of the following maps
would give you the most complete information?
A) map of active volcanoes
B) map of mid-ocean ridges
C) map of earthquake distribution
D) map of the edge of continental shelves
E) map of hot spots
16. (5 pts) The Hawaiian Islands are an example of:
A) Two Ocean plates converging
B) Two Continental plates converging
C) Diverging plates
D) Hot Spots
E) Transform Fault Boundary
Geol 15 Mid Term I 200 Points
17. (5 pts) The youngest seafloor rocks are found:
A) nearest to the mid-ocean ridges
B) nearest to the continental shelves
C) evenly distributed throughout the ocean
D) underneath the continents
E) where the ocean is the flattest
18. (10 pts) Explain the concept of convection. Describe how convection may work in the Mantle of the
earth.
Heat generated in the core causes the mantle to heat up. As the mantle heats, the mantle becomes
less dense. As the mantle becomes less dense than the surrounding mantle, it rises. When the mantle
reaches the crust, it transfers heat to the crust and cools. When the crust cools, it becomes less dense.
When the crust becomes less dense, it sinks back down towards the core.
19. (10 pts) Describe how the Hawaiian Islands were formed and explain how they are evidence for plate
motion.
The Hawaiian Islands are volcanoes that are formed when a hot spot pierces the crust with magma,
turning into lava. As the crust/plate moves over the hot spot, new volcanoes form in the new relative
location of the hot spot. Because the volcanoes are progressively older to the west-northwest, the
plate has been moving to the east-southeast.
20. (5 pts) How quickly do plates move relative to each other?
A) millimeters per second
B) millimeters per minute
C) millimeters per day
D) millimeters per year
E) Faults don't ever slip
21. (5 pts) Which type of fault is a Transform Fault?
A) Normal Fault
B) Reverse Fault
C) Thrust Fault
D) Blind Fault
E) Strike Slip Fault
22. (5 pts) What causes earthquakes in San Francisco?
A) Dip-slip faults from Subduction
B) Transform faults
C) Dip-slip faults from divergent plate boundaries
D) Dip-slip faults from convergent plate boundaries
Geol 15 Mid Term I 200 Points
23. (10 pts) What are the main types of lithospheric plate boundaries, described in terms of relative
motions? Provide a real example of each (by name or location).
ANSWER: Rift (or spreading) zones: Mid-Atlantic Ridge; subduction zones: Cascadia subduction zone
(High Cascades); continental collision zones: India against Asia (Himalayas); transform faults: San
Andreas Fault
24. (5 pts) The age of the Earth is about ________________.
A. 10 million years
B. 100 million years
C. 1000 million years
D. 460 million years
E. 4600 million years
25. (5 pts) The hotspot-melting-through-lithosphere process forms lines of extinct volcanoes on the
ocean floor, from youngest to oldest, ______________________.
A. with random ages along the lines
B. in a direction pointing toward the sun
C. pointing at 90 degrees to the direction of plate movement
D. pointing in the opposite direction of plate movement
E. pointing in the direction of plate movement
26. (5 pts) Moving progressively away from the ridges, the ocean water depths increase systematically
with seafloor age due to all but which of the following?
A. cooling and contraction of the oceanic crust with a resultant increase in density
B. isostatic down warping due to the weight of sediments deposited on the sea floor
C. erosion of the older ocean floor by deep ocean currents
D. conduction of heat away from the molten surface rocks
27. (5 pts) When oceanic lithosphere collides with another plate, the ________ in the process of
subduction.
A. older, colder plate goes beneath the younger, warmer plate
B. younger, warmer plate goes beneath the older, colder plate
C. plates both disappear downward
D. plates pile up, forming mid-ocean ridges
28. (5 pts) The __________ is measured in cross-sectional view as the angle of inclination from
horizontal of a tilted rock layer, and _______ is viewed in map view as the compass bearing of the rock
layer where it intersects a horizontal plane.
A. strike; strike
B. dip; dip
C. strike; dip
D. dip; strike
E. strike and dip; strike and dip
Geol 15 Mid Term I 200 Points
29. (5 pts) ________ faults are commonly found at areas of plate convergence where subduction or
continental collision occurs.
A. Reverse
B. Normal
C. Transform
D. Strike-slip
30. (5 pts) Can the same fault be classified as both a strike-slip and a transform fault?
A. yes
B. no
C. only if it is also a reverse fault
D. only if it is also a normal fault
31. (5 pts) The fault shown in the map view to the
right is a
a. Reverse fault
b. dip-slip fault
c. right-lateral, strike-slip fault
d. left-lateral, strike-slip fault
___________________________________________________________________
The following two questions refer to the two “map view” drawings below of steps in strike-slip
fault systems (i.e., constraining or releasing bends)
FIGURE A
FIGURE B
32. (5 pts) Figure A is a _____________________________.
a. right-lateral strike slip fault system that causes compression.
b. right-lateral strike slip fault system that causes extension.
c. left-lateral strike slip fault system that causes compression.
d. left-lateral strike slip fault system that causes extension.
Geol 15 Mid Term I 200 Points
33. (5 pts) Figure B is a ______________________________.
a. right-lateral strike slip fault system that causes compression.
b. right-lateral strike slip fault system that causes extension.
c. left-lateral strike slip fault system that causes compression.
d. left-lateral strike slip fault system that causes extension.
34. (20 pts) Plate Motion Estimate (Rate).
The southeast Indian Ridge is a spreading ridge that is marked by a line symbol that looks like a railroad
track map symbol. Measure the distance on the map between the spreading ridge and the 10, 20, and
30 Ma isochrons, convert to real world distance, then calculate the spreading rate in mm/year). This is
very similar to the plate rate estimate we made for the Mid Atlantic Ridge, the East Pacific Rise, and the
Hawaiian Islands. Show your work.
Rate for 0-10Ma: _28.7 mm/yr__ Rate for 10-20 Ma: __29.7 mm/yr__ Rate for 20-30 Ma: _36.4 mm/yr