Geol test 3 – Flashcards

Most oceanic islands and seamounts are: a.) small pieces rifted apart from continents b.) places where the seafloor has been buckled upward by convergence c.) constructed by volcanic eruptions that first occur under water d.) large fan-shaped mounds deposited by turbidity currents

The image, indicating the path of a seismic wave through a segment of the Earth, shows: a.) refraction causes seismic waves to take curved paths through Earth b.) seismic waves are refracted to shallower and shallower angles at depth c.) waves are eventually bent back toward the surface d.) The image shows all of these

Most oceanic islands and seamounts are: a.)small pieces rifted apart from continents b.)places where the seafloor has been buckled upward by convergence c.)constructed by volcanic eruptions that first occur under water d.)large fan-shaped mounds deposited by turbidity currents

What setting has the thinnest cover of sediment in the oceans? a.) mid-ocean ridges b.) abyssal plain c.)oceanic trenches d.) continental shelves and slopes along passive margins

Which of the following is characteristic of a transgression? a.) the seas move out, uncovering more land b.) sand dunes and river sediments can be deposited over marine deposits c.) marine sedimentary facies move toward the land d.) all of these

Which of the following situations would result in angular clasts? a.) transport of the clasts over long distance b.) working of clasts by waves on a beach c.) steep slopes in a mountain d.) dunes formed by wind

What type of deformation is shown in this photograph? a.) displacement b.) rotation c.) internal strain of the rock d.) columnar joints

What are the three main types of stress? a.) compression, tension, and shear b.) confining stress, deformation, and folding c.) convergence, divergence, and transform faulting d.) positive, negative, and neutral e.) none of these

Using the stratigraphic section and photographs located in the textbook (Chapter 7 Investigation), determine the possible environments of deposition for the upper sandstone and mudstone unit. a.) steep mountain front b.) river system c.) middle of a lake d.) sandy beach or delta e.) coral reef

Which of the following is most likely to occur at deep crustal levels? a.) ductile behavior b.) brittle deformation c.) fracturing d.) only minor changes in minerals e.) none of these

What kind of structure is shown in this image? a.) monocline b.) strike-slip fault c.)Correct d.)asymmetric fold e.)subduction zone

Which of the following attributes does NOT apply to these sediments? a.) angular clasts b.) cobbles and boulders c.) well sorted d.) composed of gravel

Which of the following is a typical way in which siltstone and shale are expressed in the landscape? a.) soft slopes covered by small, loose chips b.) slopes covered by loose debris from overlying rocks c.) valleys and other low areas carved into the landscape d.) badlands e.) all of these

Which of the following indicates that a fault is present in the center of this photograph? a.) the rocks are folded into an anticline b.)the offset and termination of the rock layers c.) the dark coloring on rocks on the left side d.) the lack of dark coloring on rocks to the right e.) all of these

Which environment is most likely to deposit a breccia? a.) sand dunes b.) braided river c.) meandering river d.) debris flow e.) none of these are likely to deposit a breccia

If you had this type of deformation of a region, it would: a.) thicken the crust and cause subsidence b.) thicken the crust and cause uplift c.) thin the crust and cause subsidence d.) thin the crust and cause uplift e.) none of these

What can a continental hot spot lead to? a.) formation of a curved continental outline along two rifts b.) localization of a river and delta along the failed arm of the rift c.) a thick accumulation of basalts and other volcanic rocks d.) a region that is high in elevation relative to adjacent parts of the continent e.) all of these

Which numbered site is likely to have a thin sequence of sediments over crystalline rocks of the basement? a.) 1, the continental shield b.) 2, the continental platform c.) 3, a basin in the continent d.) 4, a continental shelf e.) 5, a deep sediment-filled basin next to the continent

Many sedimentary rocks exposed in the Denver region are tilted at a high angle to the horizontal, indicating that: a.) they were originally deposited that way b.) they were deformed after they were deposited and lithified c.) they were all deposited along steep mountain fronts

If you had this type of deformation of a region, it would: a.) thicken the crust and cause subsidence b.) thicken the crust and cause uplift c.) thin the crust and cause subsidence d.) thin the crust and cause uplift e.) none of these

This diagram indicates that: a.) S-waves are the first wave to arrive at station and then die out into P-waves b.) S-waves are the last wave to arrive at the station c.) P-waves arrive first, followed by S-waves d.) surface waves arrive first, followed by S-waves and then P-waves e.) surface waves cause the smallest vibrations

Fold and thrust belts: a.) form where thrust faults cut through a thick sequence of layered rocks b.) contain cleavage and joints c.) displace older rocks over younger ones d.) all of these

The large cross beds in these rocks indicate that the sediment was deposited: a.)deep in the ocean b.) in a lake with a gently sloping bottom c.) by the wind or a water current d.) by a debris flow e.) all of these

Which numbered area on this geologic map of North America consists of recently added tectonic terranes? a.) 1, southern Alaska b.) 2, continental platform of west-central Canada c.) 3, continental shield of eastern Canada d.) 4, coastal plain along the Gulf Coast of the U.S.

Which of the following correctly matches the tectonic setting of a mountain belt with an example? a.) subduction zone-East Africa b.) continental collision-Andes Mountains c.) mantle upwelling-Tibet d.) all of these e.) none of these

The cause of the P-wave shadow zone includes: a.) P-waves are converted to S-waves, which cannot travel through the core b.) some P-waves are refracted upward before they reach this zone c.) some P-waves are refracted inward into the core, through which they cannot travel d.) the P-waves travel curved paths and are prevented from reaching the core-mantle boundary e.) all of these

Gradational boundaries between different sedimentary rock types can form from: a.) slowing of the current over time b.) a progressive change from one environment to another c.) a gradual rise or fall in sea level d.) all of these

Which of the following does NOT help define foliation in metamorphic rocks? a.) a dominant orientation of crystals, such as mica b.) light- and dark-colored bands c.) flattened shapes of deformed objects, such as pebbles d.) crystals that grow in a random orientation e.) all of these

What type of feature is shown in this image? a.) a fold in metamorphic rocks b.) a scarp along a strike-slip fault c.) erosion of gently tilted layers d.) a hogback

Why did the Christchurch earthquake (2011) in New Zealand cause much more damage than the larger Canterbury earthquake (2010)? a.) it was larger in magnitude and was deeper b.) it was closer to a large city with buildings that had c.been damaged by the earlier earthquake a large landslide from the Southern Alps mountain range buried the capital city all of these

Which of these numbered features is on the continental shelf? a.) 1 b.) 2 c.) 3 d.) 4 e.) none of these

Which of the following matches a sedimentary rock with a possible metamorphic equivalent? a.) sandstone-greenstone b.) basalt-marble c.) limestone-quartzite d.) shale-slate e.) none of these

What is a popular model for the formation of an atoll? a.) a moderate-sized meteoroid forms a circular crater on the seafloor b.) a volcanic eruption forms a large circular caldera c.) a volcanic island forms and subsides d.) a barrier reef becomes buried by volcanic eruptions

Which of the following places would NOT be a good place to visit a reef? a.) shallow seas that are relatively free of suspended sediment b.) the area offshore of northeastern Australia the Caribbean c.) islands in the southwestern Pacific Ocean d.) shallow, clear waters off Iceland

Which of the following characterizes mid-ocean ridges? a.) contact metamorphism near magma chambers b.) normal faults c.) tension d.) metamorphism associated with hot seawater e.) all of these

For a terrane to become attached to a continent, it typically: a.) enters a subduction zone, where it is scraped off the subducting plate and added to the continent b.) floats across the ocean until it becomes lodged against the coast of a continent c.) is welded to the continent through volcanic activity d.) must result from the development of a hot spot and continental rifting

Subduction is not always accompanied by compression and thrust faulting in the overriding plate. This is especially true when: a.) the overriding plate is either not moving toward the subducted slab relative to the asthenosphere, or it is moving away b.) the overriding plate is moving toward the subducted slab relative to the asthenosphere c.) no magma is created by the subduction process d.) an accretionary prism has developed at the convergent plate boundary

Overall, a P-wave increases in velocity with depth. This implies that: a.) rocks are increasing in density with depth b.) rocks are decreasing in density with depth c.) rocks do not change density with depth d.) the P-waves travel curved paths and are prevented from reaching the core-mantle boundary e.) P-waves cannot travel through molten material

Which of the following types of faults does NOT generate earthquakes? a.) normal fault b.) reverse fault c.) thrust fault d.) strike-slip fault e.) all types of faults can generate earthquakes

What type of structure is shown in this figure? a.)thrust fault b.)anticline c.)syncline d.)monocline e.)dome

Why does the elevation of the seafloor decrease from the mid-ocean ridge to the abyssal plain? a.)The oceanic lithosphere cools and becomes denser. b.)The weight of sediments depresses the oceanic crust. c.)The oceanic plate is flexed downward near a subduction zone. d.)Slab rollback pulls the oceanic lithosphere deeper.

Geologists can investigate the interior of the Earth by: a.)examining rocks that once resided at great depths b.) subjecting rocks to high temperature and pressure in laboratory settings c.) creating computer and numerical models to model processes that occur at depth d.) all of these are ways geologists can investigate the interior of the Earth

Mountain streams and rivers typically are characterized by: a.)steep gradients and are confined by bedrock canyons b.)low gradients and unconfined channels c.)steep gradients and unconfined channels d.)low gradients and are confined by bedrock canyons

Does the change of environment from the base of the section up to the thick gray shale indicate an advance (transgression) or retreat (regression) of the sea? a.)transgression b.)regression

In the Atlantic Ocean, where is the oldest oceanic crust? a.) mid-ocean ridges b.) abyssal plain next to the continents c.) oceanic trenches d.) seamounts e.) continental shelves close to the shoreline

Sudden movement on a fault can cause a tsunami when: a.) a hurricane or cyclone is occurring b.) the fault suddenly uplifts or downdrops the seafloor c.) hot water trapped below the seafloor is released d.) a fault on land has a large displacement e.) none of these

A sandstone containing mostly sand but mixed with rounded pebbles and pieces of shells indicates deposition: a.) by waves at the beach b.) by wind in dunes c.) by water far offshore d.) by mass wasting events

The diagram on the right shows the record of one earthquake on seismograms at three different stations in a seismic network. These three seismograms show: a.) ISCO station is closest to the earthquake b.) WUAZ station was right at the earthquake c.) DUG station is farthest from the earthquake WUAZ is the closest station, followed by DUG, and then ISCO d.) none of these