Q&A Hero

Q: Over the course of the last couple of centuries, major businesses all over the world have spent a great deal of time and money searching for and studying structural geologic features in order to find deposits of petroleum. How would these structures trap the substances these companies are interested in?

Q: Despite not seeing the severe tectonic forces of the Rocky Mountains, the interior states of Illinois and Michigan have basins (the Illinois and Michigan basins). However, these basins formed in a different way. Explain how the Illinois and Michigan basins formed without significant tectonic influence.

Q: Although the Valley and Ridge province of the Appalachians is characterized by intensely folded rock, it is not the structures themselves that are resulting in the ridges and valleys. What rocks make up the Valley and Ridge province, which ones make each landform (ridges or valleys), and why?

Q: The Appalachian Mountains were formed when the North American continent collided with Africa to form the supercontinent Pangaea over 250 million years ago. What kind of tectonic boundary existed here? What sort of structural features would you expect to find in this region?

Q: What are the four factors that influence rock strength? Describe how they will affect the rock when it is under stress.

Q: Explain the role that confining pressure has on rock strength and how the rock deforms under pressure.

Q: Match the fault with the appropriate stress that caused it. A) Shear B) Compression C) Tension 1. Normal fault 2. Reverse fault 3. Strike-slip fault

Q: Match the deformation with the correct definition. A) Rocks will change shape due to pressure but return to their original state when pressure is released. B) Rocks will shatter due to pressure. C) Rocks will change. 1. Elastic deformation 2. Ductile deformation 3. Brittle deformation

Q: Determine the type of stress necessary to produce each of the following geologic regions/features. (Note: Some choices will be used more than once.) A) Shear B) Tension C) Compression 1. Basin and Range province 2. San Andreas Fault 3. Grand Teton Mountains 4. Appalachian Mountains 5. Dakota Hogback

Q: uMatch the type of stress to the correct definition. A) Forces move toward each other. B) Forces slide past each other. C) Forces pull apart from each other. 1. Tension 2. Compression 3. Shear

Q: Dip will always be 90 away from strike.

Q: Joints are fractures in a rock created by tension and will demonstrate significant displacement.

Q: Some strike-slip faults are big enough to accommodate movement between two tectonic plates.

Q: A syncline is a downfold in rock where the youngest layers are in the middle of the fold and the youngest are on the outside.

Q: Shearing produced fault zones in the deep crust and folding in the upper crust.

Q: Rocks subjected to heat will be more likely to go through brittle deformation when stressed.

Q: Shear stress is a type of confining pressure.

Q: Strained geologic materials lose their original configuration during deformation.

Q: Movements along normal faults can produce alternating upthrown and down-dropped fault blocks. What are the names associated with these blocks, respectively? A) Synclines and anticlines B) Domes and basins C) Horsts and grabens D) Left-lateral and right-lateral

Q: How do joints form in tectonic environments? A) Rocks near the surface are stretched and pulled apart. B) Hot rocks cool and contract. C) Water dissolves rock along fractures. D) Rock fractures through heating.

Q: How will rock salt likely respond when put under stress? A) It will fault B) It will bend or flow C) It will dissolve D) It will fragment

Q: Detachment faults are low-angle ________ faults. A) thrust B) normal C) reverse D) strike-slip

Q: Which of the following statements best describes the relationship between the topography of a region and the underlying structural geology? A) Upfolds in the rock will make mountains and downfolds will make valleys. B) Downfolds in the rock will make mountains and upfolds will make valleys. C) There is no relationship between structures and topography.

Q: Which of the following best describes the age relationship of the layers in an anticline? A) Oldest on the outside of the fold, youngest on the inside B) Oldest on the inside of the fold, youngest on the outside C) Oldest materials thrust up on top of younger layers D) Horizontal bedding with the youngest layers on the top

Q: How will strike and dip marks be oriented on the geologic map of a nonplunging syncline? 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) Strikes intersecting, but no dips because of horizontal layering D) Parallel strikes with dips pointing toward from the center of the fold

Q: ________ is the angle of inclination of the surface of a rock unit measured from a horizontal plane. A) Dip B) Faulting C) Strike D) Plunge

Q: ________ is the compass direction of the line produced by the intersection of an inclined rock layer with a horizontal plane. A) Dip B) Angle C) Strike D) Plunge

Q: Which of the following are examples of fault-block mountains? A) Himalayas B) Rocky Mountains C) Basin and Range D) Alps

Q: Fault-block mountains are created due to ________ faults. A) reverse B) strike-slip C) thrust D) normal

Q: What are slickensides? A) Joints made as an igneous rock cools and contracts B) Fractures made in a rock as a result of tensional stress C) Folded rocks along a convergent boundary D) Polished and striated surfaces made on fault blocks

Q: What is the difference between faults and joints? A) Joints are the result of compression, whereas faults are the result of tension. B) Joints are the result of earthquakes, and faults are the result of weathering. C) Joints form in place, whereas faults form because rock has moved. D) Joints form from external stress, and faults form from cooling.

Q: Some of the most destructive earthquakes, such as the Haitian earthquake of 2010, occur along ________ faults. A) reverse B) strike-slip C) thrust D) normal

Q: Which type of fault was responsible for the devastation associated with the 1906 earthquake in San Francisco? A) Transform B) Normal C) Reverse D) Thrust

Q: 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? A) Left-lateral strike-slip B) Right-lateral strike-slip C) Thrust D) Normal

Q: A ________ fault has a vertical fault plane and shows movement parallel to the orientation of the fault. A) reverse B) strike-slip C) thrust D) normal

Q: Mountain ranges such as the Appalachians and the Himalayas are examples of mountains that formed as a result of ________ faulting. A) thrust B) normal C) strike-slip D) transform

Q: Faults that exhibit both dip-slip and strike-slip movement are called ________ faults. A) thrust B) horst C) normal D) oblique-slip

Q: Which of the following scenarios would best indicate that a thrust fault is present at a location? A) The hanging wall of the fault has slipped down. B) Two parts of the same rock have been horizontally displaced by 20 feet. 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.

Q: Which tectonic boundary would have many thrust faults associated with it? A) Convergent B) Divergent C) Transform

Q: What is the difference between a reverse fault and a thrust fault? A) A reverse fault is the result of compression, and a thrust fault is the result of tension. B) A reverse fault lengthens the crust, whereas a thrust fault shortens the crust. C) A thrust fault has a fault angle of less than 45, whereas the angle of a reverse fault is greater. D) Reverse faults are associated with convergent boundaries, and thrust faults are associated with transform boundaries

Q: A ________ fault is created when the hanging wall moves up relative to the footwall. A) strike-slip B) normal C) reverse D) graben

Q: Which tectonic boundary would have many normal faults associated with it? A) Convergent B) Divergent C) Transform

Q: 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. A) recumbent B) overturned C) plunging D) inverted

Q: What is the outcrop pattern of a plunging syncline? A) The layers will close to a point in the direction of plunge. B) The layers will be oriented parallel to each other. C) The layers will intersect at right angles. D) The layers will open up in the direction of plunge.

Q: How many hinge lines does a monocline have? A) One B) Two C) Three D) Four

Q: You are sitting in class when your professor begins talking about a dome with the inner layers dating back to the Tertiary and its outer layers dating back to the Permian. You immediately know this professor is wrong. What is your evidence? A) Domes don't have layers. B) Domes have the oldest layers in the middle, not the youngest. C) Now that we know the age of the layers, we would call it a syncline. D) Domes didn't exist back then.

Q: A ________ is a circular fold where the youngest layers are in the middle and the oldest layers are on the outside. A) syncline B) monocline C) dome D) basin

Q: Faults form in ________ temperature-________ pressure environments. A) low-; low- B) high-; high- C) high-; low- D) low-; high-

Q: Folds form in ________ temperature-________ pressure environments. A) low-; low- B) high-; high- C) high-; low- D) low-; high-

Q: What is a fault? A) A fracture in a rock along which motion has occurred B) A stress fracture created by rocks stretching and pulling apart near the surface C) A solution pathway created by carbonic acid D) Foliation in a rock that acts as a plane of weakness

Q: 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? A) Rock salt B) Sandstone C) Schist D) Quartzite

Q: Which of the following is an example of brittle deformation? A) Squeezing a rubber ball and seeing it bounce back B) Denting the fender of a car C) Throwing a hammer through a glass windowpane D) Pressing on a spring and seeing it rebound

Q: Unbending a paper clip wire is an example of what kind of deformation? A) Brittle deformation B) Ductile deformation C) Elastic deformation D) Shear deformation

Q: A rubber band being stretched in preparation to fire across the room is an example of what kind of deformation? A) Brittle deformation B) Ductile deformation C) Elastic deformation D) Shear deformation

Q: Which tectonic boundary is associated with compressional stress? A) Convergent B) Divergent C) Transform D) Dip-slip

Q: How will tensional force change a rock body? A) Stretch and thin the rock. B) Fracture the rock and grind the pieces alongside each other. C) Shorten and thicken the rock. D) The rock will not change.

Q: How will compressional force change a rock body? A) Stretch and thin the rock. B) Fracture the rock and grind the pieces alongside each other. C) Shorten and thicken the rock. D) The rock will not change.

Q: Which of the following is the best description for structural geology? A) Study of intergrown mineral crystals in igneous rocks B) Study of sequences of sedimentary rocks and how their environments of deposition dictate how sediments are laid down C) Study of earthquakes and how they move through Earth's interior D) Study of rock deformation in response to tectonic forces

Q: ________ refers to the changes in shape or position of a rock body in response to differential stress. A) Stress B) Deformation C) Compression D) Brittle failure

Q: Using the geologic cross section above, put the rock layers in order from oldest to youngest. Use the blanks to the right of the figure for your answers. A) m B) p C) z D) h E) x F) c G) t 1. Oldest (top line) 2. Second line from the top 3. Third line from the top 4. Fourth line from the top 5. Third line from the bottom 6. Second line from the bottom 7. Youngest (bottom line)

Q: Assume that Layer C is a lava flow that has been radiometrically dated to 97 million years ago. What is the age of Layer Z? A) Younger than 97 million years old B) Older than 97 million years old C) Younger than 45 million years old D) Exactly 97 million years old

Q: What kind of radioactive decay is present in this image? A) Alpha decay B) Beta decay C) Electron capture

Q: Which rock layer is the youngest in this image?

Q: Which rock layer is the oldest in this image?

Q: What kind of unconformity is visible in this figure? The unconformity in the question is indicated by the Arrow B. A) Disconformity B) Nonconformity C) Angular unconformity

Q: What kind of unconformity is visible in this figure? The unconformity in question is indicated by the Arrow A. A) Disconformity B) Nonconformity C) Angular unconformity

Q: Explain how the feature in this image formed.

Q: What geologic feature is present in this image?

Q: Why is it that scientists know less about the first four-fifths of Earth's history than about the last, most recent one-fifth?

Q: Compare and contrast the three common types of radioactive decay: alpha particle decay, beta particle decay, electron capture. Your answer should include how the atomic mass and the atomic number of the isotope have changed.

Q: Assuming that humans went extinct today, do you think that they would be good index fossils? Why or why not?

Q: You are studying an outcrop where the base layer is limestone and the layer directly on top of that is sandstone. Near the base of the sandstone are small, weathered pieces of limestone entirely contained within the sandstone. Explain how these pieces of limestone came to be contained within the sandstone.

Q: A basalt dike is found in a body of granite. Which is older and why?

Q: One method of geologic dating is dendrochronology, or the science of tree ring dating. Based on what you know about tree rings, how could you determine the age of the tree? Would this be an example of relative dating or numerical dating?

Q: Name the periods of the Paleozoic era in order from oldest to youngest.

Q: What is the ratio of parent atoms to daughter atoms after three half-lives?

Q: Put the units of the geologic time scale in order from largest to smallest. (Note: In this situation, First refers to the largest time period and Fourth refers to the smallest times period.) A) Eon B) Era C) Period D) Epoch 1. First (largest period) 2. Second 3. Third 4. Fourth (smallest period)

Q: Match the parent isotope with the correct daughter isotope. (Note: Some answers will be used more than once.) A) Lead B) Strontium C) Argon D) Nitrogen 1. Uranium 2. Potassium 3. Carbon 4. Thorium 5. Rubidium

Q: Match the type of fossilization with the correct definition. A) Indirect evidence of fossil life (i.e. tracks, burrows) B) Hollows left by dissolved fossils are filled with mineral matter C) Fine sediment encases plant remains, leaving behind an organic residue D) Organic pores are filled with precipitated minerals 1. Permineralization 2. Cast and mold 3. Carbonization 4. Trace Fossil

Q: Match the relative dating principles with the correct definition. A) Missing time. B) Faults, fractures are younger than the rocks they cut through. C) Sedimentary layers/lava D) The oldest is on the bottom, the youngest on top. E) Rocks extend in all directions until they reach the edge of a basin or pinch out. F) Chunks of weathered rock are older than the rock they are contained in. 1. Superposition 2. Original horizontality 3. Lateral Continuity 4. Cross-Cutting Relationships 5. Unconformities 6. Inclusions