Response to Differential Stress Review Answer Key

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) ________ refers to the changes in shape or position of a rock body in response to differential stress. 1) _____ A) Compression B) Stress C) Brittle failureD) Deformation 2) Which of the following is the best description for structural geology? 2) _____ A) Study of sequences of sedimentary rocks and how their environments of deposition dictate how sediments are laid down B) Study of intergrown mineral crystals in igneous rocks C) Study of earthquakes and how they move through Earth's interior D) Study of rock deformation in response to tectonic forces 3) How does compressional force change a rock body? 3) _____ A) The rock will not change B) Shorten and thicken the rock C) Stretch and thin the rock D) Fracture the rock and grind the pieces alongside each other 4) How does tensional force change a rock body? 4) _____ A) Shorten and thicken the rock B) Fracture the rock and grind the pieces alongside each other C) The rock will not change D) Stretch and thin the rock 5) Which tectonic boundary is associated with compressional stress? 5) _____ A) Divergent B) Dip-slip C) Transform D) Convergent 6) A rubber band being stretched in preparation to fire across the room is an example of what kind of deformation? 6) _____ A) Brittle deformation B) Elastic deformation C) Shear deformation D) Ductile deformation 7) Unbending a paper clip wire is an example of what kind of deformation? 7) _____ A) Brittle deformation B) Ductile deformation C) Shear deformation D) Elastic deformation 8) If you were to place a circular mark on a rock surface and then subject it to shear stress, what shape would the circle then become? 8) _____ A) OvalB) Square C) Triangular D) Rectangular 9) Which of the following rocks would be more likely to experience brittle deformation rather than ductile deformation when subjected to stresses that exceed their strength? 9) _____ A) Quartzite B) Schist C) Sandstone D) Rock salt 10) A chocolate bar will behave similarly to a rock. If you try to bend a chocolate bar at room temperature it will ________ exhibiting ________ behavior. 10) _____ A) snap; brittle B) bend; brittle C) bend; ductileD) snap; ductile 11) What is a fault? 11) _____ A) A fracture in a rock along which motion has occurred B) Foliation in a rock that acts as a plane of weakness C) A solution pathway created by carbonic acid D) A stress fracture created by rocks stretching and pulling apart near the surface 12) Folds form in ________ temperature-________ pressure environments. 12) _____ A) low-; high- B) high-; low- C) low-; low- D) high-; high 13) Faults form in ________ temperature-________ pressure environments. 13) _____ A) high-; low- B) high-; high- C) low-; low- D) low-; high 14) A ________ is a circular fold where the youngest layers are in the middle and the oldest layers are on the outside. 14) _____ A) syncline B) dome C) monocline D) basin 15) You are accuracy-checking a geologic map of a structural dome with the inner layers dating back to the Tertiary and its outer layers dating back to the Permian. You immediately know this map is wrong. What is your evidence? 15) _____ A) Domes have the oldest layers in the middle, not the youngest. B) Domes didn't exist back then. C) Domes don't have layers. D) Now that we know the age of the layers, we would call it a syncline. 16) A fold's axial plane is always run ________ Earth's surface. 16) _____ A) below B) perpendicular to C) at an oblique angle to D) parallel to 17) How many hinge lines does a monocline have? 17) _____ A) One B) Two C) Three D) Four 18) What is the outcrop pattern of a plunging syncline? 18) _____ A) The layers will open up in the direction of plunge. B) The layers will close to a point in the direction of plunge. C) The layers will be oriented parallel to each other. D) The layers will intersect at right angles. 19) A(n) ________ fold has limbs that are tilted beyond the vertical to the point that the axial plane is horizontal, giving it the appearance of lying on its side. 19) _____ A) plunging B) recumbent C) overturned D) inverted 20) Which tectonic boundary would have many normal faults associated with it? 20) _____ A) Transform B) Divergent C) Convergent 21) A ________ fault is created when the hanging wall moves down relative to the footwall. 21) _____ A) normal B) strike-slip C) reverse D) graben 22) What is the difference between a reverse fault and a thrust fault? 22) _____ A) Reverse faults are associated with convergent boundaries, and thrust faults are associated with transform boundaries. B) A reverse fault is the result of compression, and a thrust fault is the result of tension. C) A thrust fault has a fault angle of less than 45°, whereas the angle of a reverse fault is greater. D) A reverse fault lengthens the crust, whereas a thrust fault shortens the crust. 23) Which tectonic boundary would likely have many thrust faults associated with it? 23) _____ A) Transform B) Divergent C) Convergent 24) Which of the following scenarios would best indicate that a thrust fault is present at a location? 24) _____ A) Two parts of the same rock have been horizontally displaced by 20 feet. B) The hanging wall of the fault has slipped down. C) Cambrian-aged rocks have been shoved on top of Jurassic-aged rocks. D) The crust has lengthened, allowing a graben to slip down and create a pull-apart basin. 25) Faults that exhibit both dip-slip and strike-slip movement are called ________ faults. 25) _____ A) thrust B) normal C) oblique-slip D) horst 26) Mountain ranges such as the Appalachians and the Himalayas are examples of mountains that formed as a result of ________ faulting. 26) _____ A) normal B) transform C) strike-slip D) thrust 27) A ________ fault has a vertical fault plane and shows movement parallel to the orientation of the fault.27) _____ A) strike-slip B) thrust C) reverse D) normal 28) You are a seismologist and are driving out to a location where a fault has recently shifted. When you arrive at the location, you see that the road you are driving on was constructed across the fault line. Because of slippage along the fault, the road ahead has been shifted to the left by 20 feet. What kind of fault is present? 28) _____ A) Left-lateral strike-slip B) Thrust C) Normal D) Right-lateral strike-slip 29) Which type of fault was responsible for the devastation associated with the 1906 earthquake in San Francisco? 29) _____ A) Thrust B) Reverse C) Transform D) Normal 30) What is the difference between faults and joints? 30) _____ A) Joints form from external stress, and faults form from cooling. B) Joints form in place, whereas faults form because rock has moved. C) Joints are the result of compression, whereas faults are the result of tension. D) Joints are the result of earthquakes, and faults are the result of weathering. 31) What are slickensides? 31) _____ A) Fractures made in a rock as a result of tensional stress B) Polished and striated surfaces made on fault blocks C) Joints made as an igneous rock cools and contracts D) Folded rocks along a convergent boundary 32) Fault-block mountains are created due to ________ faults. 32) _____ A) thrust B) strike-slip C) normal D) reverse 33) Which of the following are examples of fault-block mountains? 33) _____ A) Rocky Mountains B) Basin and Range C) Alps D) Himalayas 34) ________ is the compass direction of the line produced by the intersection of an inclined rock layer with a horizontal plane. 34) _____ A) Strike B) Dip C) Angle D) Plunge 35) ________ is the angle of inclination of the surface of a rock unit measured from a horizontal plane. 35) _____ A) Faulting B) Dip C) Strike D) Plunge 36) How will strike and dip marks be oriented on the geologic map of a nonplunging syncline? 36) _____ A) Parallel dips with strikes pointing away from the center of the fold B) Strikes ringing the fold with the dips pointing toward the center C) Parallel strikes with dips pointing toward from the center of the fold D) Strikes intersecting, but no dips because of horizontal layering 37) Which of the following best describes the age relationship of the layers in a syncline? 37) _____ A) Oldest on the outside of the fold, youngest on the inside B) Oldest materials thrust up on top of younger layers C) Horizontal bedding with the youngest layers on the top D) Oldest on the inside of the fold, youngest on the outside 38) Detachment faults are low-angle ________ faults. 38) _____ A) strike-slip B) thrust C) normal D) reverse 39) How will rock salt likely respond when put under stress? 39) _____ A) It will dissolve B) It will bend or flow C) It will fragment D) It will fault 40) Movements along normal faults can produce alternating upthrown and down-dropped fault blocks. What are the names associated with these blocks, respectively? 40) _____ A) Domes and basins B) Synclines and anticlines C) Horsts and grabens D) Left-lateral and right-lateral 41) A fault scarp is normally formed as the result of ________ displacement 41) _____ A) normal B) transform C) strike-slip D) vertical E) horizontal