Earth History and Global Change
GEOL-1122 Spring 2014
PRACTICE for LECTURE TEST #2
Name ________________________
Part I ‑ Multiple Choice (50 pts. ‑ 2pts. each question.)
**Circle the letter of the best answer.
1) Which of the following information can be derived from the study of geologic structures?
a) Nature of the applied stress that formed the structures
b) Orientation or directions of the applied stress
c) General pressure and temperature conditions during deformation
d) All of the above
2) Most compressional and extensional stress associated with regional structures results from:
a) Movement of tectonic plates
b) Weight of overlying rocks in mountain areas
c) Erosion and uplift or older continental crust
d) Upward movement of large magma chambers
3) Which of the following conditions will result in an increase in brittle behavior?
a) Lower temperatures
b) Decreased lithostatic stress
c) Increased rate of applied stress
d) All of the above
4) Which of the following fault types is associated with compressional stress?
a) Reverse faults
b) Normal faults
c) Domes and basins
d) All of the above
5) Strike-slip faults result from:
a) Brittle deformation
b) Transform plate boundaries
c) Shear stress
d) All of the above
6) Joints commonly form by which of the following:
a) Thermal contraction
b) Near-surface deformation during mountain building
c) Unloading
d) Any of the above
7) Which of the following statements concerning anticlines is not correct?
a) They are commonly associated with mountain building.
b) They are commonly associated with normal faults.
c) They form by compressional stress.
d) They are concave in the direction of the oldest units.
8) Which of the following structures can be described by a single strike and dip measurement?
a) Monocline
b) Dome
c) Anticline
d) All of the above
9) Which of the following is characteristic of areas subjected to extensional stress?
a) Horst and graben structures
b) Normal faults
c) Crustal thinning
d) All of the above
10) Which of the following geologic structures is common along convergent plate boundaries?
a) Reverse faults
b) Synclines
c) Thrust faults
d) All of the above
11) Which of the following best describes the San Andreas Fault?
a) A left-lateral normal fault
b) A right-lateral reverse fault
c) A right-lateral strike-slip fault
d) A left-lateral strike-slip fault
12) Which of the following is a low-angle fault where the hanging-wall block is displaced upward relative to the footwall block?
a) Abnormal
b) Reverse
c) Thrust
d) Normal
13) The supercontinent Gondwana contained which of the following continents?
a) Australia, Antarctica, China and South America
b) Africa, Australia, Antarctica, Europe/Asia, North America and South America
c) Africa, Australia, Antarctica, India and South America
d) Australia, Antarctica, India, Europe/Asia and South America
14) Which of the following is a snaggle-toothed freshwater reptile fossil found on adjacent parts of Africa and South America?
a) Mesosaurus
b) Glossopterus
c) Cerodactyl
d) Hadiosaur
15) Which of the following is not commonly associated with active continental margins?
a) Thrust and reverse faulting
b) Normal faulting
c) Active seismic activity
d) Andesitic volcanism
16) Which of the following is a typical characteristic of divergent continent-continent plate boundaries?
a) Normal faulting
b) Folding and thrust faulting
c) Mountain building and crustal thickening
d) All of the above
17) Which of the following rock types would retain the position of the earth's magnetic field
during its formation?
a) High-grade metamorphic gneiss
b) Basaltic lava flow
c) Intrusive diorite
d) All of the above
18) A sample of gabbro in which the magnetic field is oriented with the north pole pointing 45°downward relative to the earth's surface probably formed:
a) Near the equator
b) Midway between the equator and North Pole
c) Midway between the equator and South Pole
d) Near the South Pole
19) Which of the following paleomagnetic orientations would be found in a lava flow that recently formed near the south pole?
a) Near horizontal or no inclination and a northward compass orientation
b) Near vertical inclination, pointing upward
c) Near vertical inclination, pointing downward
d) Slight downward inclination and a northward compass orientation
20) Identical magnetic reversal patterns are found in the rocks on the opposite sides of:
a) Mantle hot spots
b) Subduction zones
c) Convergent oceanic-oceanic crustal areas
d) Oceanic ridges and rises
21) Which of the following areas is an example of a divergent continental boundary?
a) Western South America
b) East Africa
c) Alaska
d) Southern California
22) Which of the following statements about the asthenosphere is not correct?
a) It deforms or behaves plastically.
b) It is located within the mantle.
c) It lies directly below the lithosphere.
d) It will not transmit S-waves.
23) Which of the following rock types is not commonly used to determine paleoclimates?
a) Coal
b) Mudstone
c) Rock gypsum
d) Limestone
24) Which of the following statements concerning the lithosphere is correct?
a) It is composed of the crust and an upper brittle mantle layer
b) It average approximately 100 kilometers in thickness
c) It is an area of brittle deformation
d) All of the above
25) Which of the following is the best estimate of the average rate of plate movement?
a) 2-5 centimeters per year
b) 2-5 meters per year
c) 2-5 kilometers per year
d) 2-5 millimeters per year
PART II ‑ Fill in the Blank (40 pts. ‑ 2 pts. each question.)
26-27) Long linear __________________ faults which form due to extensional stress result in the formation of subparallel linear valleys separated by linear mountain ranges called ____________________________________.
28) Circular or elliptical synclinal structures that form by the subsidence of basement rocks are called ______________.
29) Fractures along which there has been visible movement are called ______________.
30) A type of linear fold that is concave in the direction of the older units is called a/an ___________________________
31-32) A type of strain in which the material instantly and totally recovers its original shape when stress is released is called _______________________ strain. In contrast, if there is permanent change in the shape and/or size without rupture it is called _________________________ strain.
33) The Coastal Plain of the southeastern United States (including Georgia) is an example of a/an _______________________ structure.
34) ____________________________ is the theoretical balance of rigid crustal segments above a deformable mantle layer (associated with differences in crustal density and thickness).
35) _______________________ is a subpolar fern that is found as fossils on the Gondwana continents.
36) _________________ it the meteorologist credited for proposing the Plate Tectonic Theory.
37-38) Name a geographic example of a hot spot chain and describe how it forms. _________________________________________________________
__________________________________________________________________
39-41)(6 pt) Describe how the following properties of adjacent oceanic crust change (increase, decrease or stay constant) as you move away from an active spreading ridge or rise.
d) Rock density: _________________________________
e) Water depths to oceanic crust: ____________________
f) Elevation of the oceanic crust: _____________________
a) Crustal temperatures: ___________________________
b) Sediment thickness: ____________________________
c) Rock ages: ___________________________________
42-43) Name two of the major rock types that are found in the Gondwana sequence and described how they formed:
a) _______________________________________________________________
b) _______________________________________________________________
44) The most important mechanism responsible for plate tectonic movement is ________________________________________________________________________
45) A geographic example of a passive continental margin is ____________________.
46) Continental margins characterized by inclined seismic activity where there is a direct correlation with the depth of the earthquake and the distance from the coastline are called ___________________ (not subduction zones).
47) The subduction of oceanic crust beneath other oceanic crust results in the formation of linear chains of volcanic islands called _____________________.
48) Name a geographic example (location) of modern transform plate boundary. ______________________________
49) Name and describe a location on the earth’s surface (not under water) where you can directly measure the current rate of plate movement. __________________________________________________________________________________________
50) The highest mountain range in the world has formed by continent-continent collision. This mountain range is called the __________________ Mountains.
Extra Credit (2 pt):
What is another name for the asthenosphere?
__________________________________