Crustal Deformation and Mountain Building

D) a mass of rock that formed elsewhere and was add

A terrane is __________. A) the continent receiving new land additions B) the exact location where an oceanic plate is forced beneath a continental plate C) the overriding plate at a subduction zone D) a mass of rock that formed elsewhere and was added to a continent E) a chain of volcanoes that will form near a convergent boundary

C) a strike-slip fault that forms the boundary between tectonic plates

A transform fault is ________. A) a reverse fault that steepens into a thrust fault B) the rift bounding fault on a mid-ocean ridge C) a strike-slip fault that forms the boundary between tectonic plates D) a dip-slip fault connecting an anticline with a syncline

sycline

A trough, or downward fold, called a(n) _______ is formed when a rock is deformed through folding.

C) strike slip

A(n) ________ fault has little or no vertical movements of the two blocks. A) stick slip B) oblique slip C) strike slip D) dip slip

C) accretionary-wedge complex

A(n) ________ is a thick accumulation of sediments and small tectonic blocks formed of material scraped off subducting oceanic lithosphere at a convergent margin. A) continental shelf, terrain complex B) mass movement complex C) accretionary-wedge complex D) subterranean-accumulation complex

C) uplift and erosion

Batholiths, such as those that make up the Sierra Nevada Mountains of California, form at great depth in the crust. How could they have been exposed at the surface? A) compression B) subduction C) uplift and erosion D) shearing E) accretion

D) younger; older

Exhumed basins contain ________ rocks in the center of the structure and domes contain ________ rocks in the center. A) younger; younger B) older; older C) older; younger D) younger; older

A) marine basin between India and Eurasia.

Folded limestones that are exposed high elevations in the Himalayas were originally deposited as sediments in a ________. A) marine basin between India and Eurasia. B) deep ocean trench along the southern margin of India. C) late Paleozoic syncline north of the Tibetan Plateau. D) Cenozoic fault basin between Africa and Arabia.

D) ductile deformation

Folds are an example of ________. A) shear deformation B) brittle deformation C) elastic deformation D) ductile deformation

D) joints

Fractures in rock with no offset (where there has been no motion) are called ________. A) fractures B) sutures C) accretionary wedges D) joints

D) normal

Grabens are formed by what type of faulting? A) strike-slip B) collision C) reverse D) normal

anticline

If a rock undergoes folding and is compressed to form an upward arch, this is a(n) ______ type fold.

D) The roots would rebound upward.

If the Rocky Mountains were eroded, what would happen to the roots of the mountains? A) The roots would be deformed. B) The roots would remain in their original location. C) The roots would sink down. D) The roots would rebound upward. E) The roots would melt.

B) Nonplunging folds look like straight lines at the surface, and plunging folds look like wavy lines.

Imagine a fold has been eroded to a flat surface. In general, how would you know whether this fold is plunging? A) Nonplunging folds look like valleys at the surface, and plunging folds look like hills. B) Nonplunging folds look like straight lines at the surface, and plunging folds look like wavy lines. C) Nonplunging folds look like wavy lines at the surface, and plunging folds look like straight lines. D) Nonplunging folds look like hills at the surface, and plunging folds look like valleys.

C) Rocks would be oldest on the edges and youngest in the middle.

Imagine a syncline has been eroded to a flat surface. How would the rock age change as you walked across that flat surface? A) Rocks would be youngest on the right and oldest on the left. B) Rocks would be youngest on the left and oldest on the right. C) Rocks would be oldest on the edges and youngest in the middle. D) Rocks would be youngest on the edges and oldest in the middle.

C) Rocks would be youngest on the edges and oldest in the middle.

Imagine an anticline has been eroded to a flat surface. How would the rock age change as you walked across that flat surface? A) Rocks would be youngest on the left and oldest on the right. B) Rocks would be youngest on the right and oldest on the left. C) Rocks would be youngest on the edges and oldest in the middle. D) Rocks would be oldest on the edges and youngest in the middle.

D) reverse

In a(n) ________ fault, the hanging wall block moves up with respect to the footwall block. A) normal B) strike slip C) abnormal D) reverse

B) more than 90 degrees

In an overturned fold, the beds have rotated ________. A) 100 to 150 degrees B) more than 90 degrees C) more than 45 degrees D) more than 180 degrees

A) subside

In the interior of continents the earth's crust is typically about 40km thick and the elevation is near sea level. Most earth materials expand when heated, lowering their density. During rifting continental margins are heated but cool as sea floor spreading moves offshore from the continent. Thus, basic isostasy suggests that after rifting, a continental margin will ________. A) subside B) uplift C) rise slowly as erosion removes uplifted rocks D) remain near sea level

C) the crust is shortened and thickened

In thrust faulting, ________. A) grabens develop on the footwall block B) the hanging wall block slips downward along the thrust fault C) the crust is shortened and thickened D) horizontal, tensional stresses drive the deformation

A) subduction

Island arcs and Andean type mountains are both examples of mountains formed by ________. A) subduction B) transform faults C) collisional tectonics D) rifting/oceanic spreading

A) basins

Large circular downwarped structures are called ________. A) basins B) anticlines C) synclines D) domes

normal

Large rifts or valleys, which can often have very large _______faults, are created by tensional forces.

D) earthquakes

Most active faults pose a risk to society because they can potentially produce ________. A) tsunamis B) disruptions in groundwater flow C) landslides D) earthquakes

B) thickening of the crust in mountain belts produces a weak deep crust the spreads by gravity collapse, limiting the elevation

Most geologists think the elevation of mountains above sea level is limited by earth's gravity because ________. A) rock cliffs are subject to gravity failure and can only be about 1km high B) thickening of the crust in mountain belts produces a weak deep crust the spreads by gravity collapse, limiting the elevation C) rocks can never reach escape velocity D) the earth's mantle is too weak to support the load of large mountains

D) the exhumed roots of a subduction related magmatic arc

Most granitic batholiths represent ________. A) a deeply exhumed forearc rock assemblage B) magmas generated in a rift system, prior to development of a passive margin C) a deeply exhumed passive continental margin D) the exhumed roots of a subduction related magmatic arc

A) thrust

Mountain building uplifts rocks against the force of gravity raising their potential energy, which requires work by the earth system. Based on the relative motion of fault blocks, what type of fault would you expect to require more energy than the others? A) thrust B) strike-slip C) normal D) There is no way of knowing based on information data given.

B) mountains

Orogenesis refers to the formation of ________. A) accretionary wedges B) mountains C) mineral deposits D) fault planes

C) Ranges are uplifted horst blocks while basins formed as grabens.

Southwestern North America contains a large area called the Basin and Range province. What is the origin of this name? A) The area is characterized by chains of volcanoes forming ranges next to basins that form valleys. B) Thrust faulting along the San Andreas fault produces linear ridges, the ranges, with intervening basinal valleys forming fault block mountains. C) Ranges are uplifted horst blocks while basins formed as grabens. D) Folds have formed by compressional stresses along the plate margin forming ridges (ranges) and valleys (the basins) of the basin and range province.

A) melting of the asthenosphere above the subducting oceanic plate by fluids acting as a flux to enhance melting

Studies of the chemistry of rocks from arc volcanoes indicate the main source of the magma is ________. A) melting of the asthenosphere above the subducting oceanic plate by fluids acting as a flux to enhance melting B) melting of the asthenosphere above the subducting oceanic plate by frictional heating on the subduction interface C) melting of the subducted mantle lithosphere D) melting of subducted oceanic crust

NOT B or C

Terrane accretion generally occurs along a ________ boundary between a continental plate and a(n) ________ plate. A) convergent; continental B) divergent; continental C) divergent; oceanic D) convergent; oceanic

C) They formed long ago, and erosion has beveled them to their present low elevation.

The Appalachian Mountains may have once been as lofty as the Himalayan-Tibetan Mountain belt is today. Why are they not this high now? A) They developed a dense crustal root following collision, and isostasy forced them to sink to their present elevation. B) The mountains cooled following the collision, which increased the density of the of the rocks by cooling, and isostasy forced the mountains to sink. C) They formed long ago, and erosion has beveled them to their present low elevation. D) Opening of the North Atlantic Ocean converted lithosphere to asthenosphere beneath eastern North America, forcing eastern North America to sink to low elevations.

A) collisional

The Appalachians were formed by three phases of ________ orogeny. A) collisional B) transform C) rifting D) Andean

D) collisional

The Himalayas and Tibet are the archetypical example of a(n) ________ mountain belt. A) Andean B) continental rift C) transform D) collisional

B) strike-slip faults

The San Andreas Fault in California and the Alpine Fault in New Zealand are examples of ________. A) normal faults B) strike-slip faults C) oblique-slip normal faults D) thrust faults

C) crustal thickening over millions of years has produced a thick crust that stands high due to Isostasy

The Tibetan plateau is high above sea level because ________. A) a giant fault beneath Tibet raises it up relative to adjacent areas B) there are many active faults across Tibet that produce internal crustal thickening and uplift C) crustal thickening over millions of years has produced a thick crust that stands high due to Isostasy D) the extrusion of East Asia has produced structures that thicken the crust under Tibet, producing regional uplift

B) ductile

The higher the temperature, the more likely it is that a rock will deform in a ________ manner. A) elastic B) ductile C) shear D) brittle

D) symmetrical fold

The type of fold that has the two limbs at the same angle is called a(n) ________. A) plunging fold B) anticline C) syncline D) symmetrical fold

D) an ancient Forearc Basin and accretionary wedge

The west coast of California is underlain by rocks that represent ________. A) an ancient volcanic arc B) an oceanic plateau C) a collisional orogenic belt D) an ancient Forearc Basin and accretionary wedge

E) The crust would move up in elevation.

Using what you know about isostasy, how would the crust behave if a large glacier were removed? A) The crust would deform. B) The crust would rift. C) The crust would do nothing. D) The crust would sag. E) The crust would move up in elevation.

D) a fold that is tilted down into Earth

What does the term plunging fold mean? A) a fold that is pushed down into Earth B) a fold that is synclined down into Earth C) a fold that is bent down into Earth D) a fold that is tilted down into Earth E) a fold that is faulted down into Earth

C) a fold shaped like a right-side-up U

What is a syncline? A) a fold shaped like an upside-down U B) a fault shaped like a right-side-up U C) a fold shaped like a right-side-up U D) a fault shaped like an upside-down U

D) a fold shaped like an upside-down U

What is an anticline? A) a fault shaped like a right-side-up U B) a fault shaped like an upside-down U C) a fold shaped like a right-side-up U D) a fold shaped like an upside-down U

A) plate tectonics theory

What is the modern theory for orogenesis (mountain building)? A) plate tectonics theory B) shrinking earth model C) geosynclinal theory D) expanding earth theory

B) accretion

What is the name of the process by which terranes are added to continents? A) extension B) accretion C) subduction D) rifting E) orogeny

A) a combination of folding and tilting

What produces plunging folds? A) a combination of folding and tilting B) a combination of folding and rotating C) a combination of rotating and tilting

B) a forearc basin

What type of basin would be most likely to contain large amounts of sediments derived from a volcanic source? A) a continental interior basin B) a forearc basin C) a passive continental margin D) a strike-slip basin

joint; fault

When a rock is under undue stress and fractures but there is no movement to either side of the fracture, the feature is a called a _______. If, however, there is movement, it is called a _______.

A) normal fault

Which fault will see the hanging wall move down relative to the footwall? A) normal fault B) thrust fault C) right-lateral strike-slip fault D) reverse fault E) left-lateral strike-slip fault

A) folding D) reverse faulting

Which of the following is an example of how rocks will respond to compressional stress? (Note: there may be more than one correct answer.) A) folding B) elongation C) normal faulting D) reverse faulting E) transform faulting

D) Brittle deformation is dominant in the shallow crust; ductile deformation is dominant in the deep crust.

Which of the following scenarios best describes the deformation that will occur in different parts of the crust? A) Folding and fracturing only occur in the deep crust, where there is more tectonic force. B) Ductile deformation is dominant in the shallow crust; brittle deformation is dominant in the deep crust. C) Folding and fracturing only occur in the shallow crust, where there is less confining force. D) Brittle deformation is dominant in the shallow crust; ductile deformation is dominant in the deep crust.

B) convergent boundary

Which tectonic boundary is associated with the addition of terranes to a continent? A) hot spot B) convergent boundary C) transform boundary D) divergent boundary

B) tension

Which tectonic stress will result in a lengthening of the crust? A) shear B) tension C) compression

C) compressional force

Which type of force causes folding? A) tensional force B) shear force C) compressional force

D) Isostasy

_____ is the principle that explains why materials uplift to a certain elevation. A) Density B) Deformation C) Subduction D) Isostasy E) Accretion

B) Oblique-slip

__________ faults combine elements of strike-slip and dip-slip motions. A) Reverse B) Oblique-slip C) Thrust D) Normal E) Strike-slip