gology exam 3

Which physical property was responsible for determining how Earth materials separate into interior layers at the time of Earth's formation?

Density

What is a mineral phase change?,

A) Atoms in a mineral are rearranged into a denser and more stable structure.;

________ is the process where materials separate into different layers due to density.

Differentiation

What is the major difference between the inner core and the outer core?,

D) The inner core is solid while the outer core is liquid.;

What is the primary method scientists use to determine the layering of the interior of the Earth?,

B) Seismic waves;

What will happen to a seismic wave when it is reflected?,

B) The wave will be bounced back toward its source.;

What will happen to a seismic wave when it is refracted?,

B) The wave will be bent when passing into a material of differing density.;

Which seismic waves would be most useful in determining the extent and thickness of the Earth's interior layers?,

A) P and S waves;

Which of the following materials will allow for the fastest transmission of seismic waves?,

D) Rigid, less compressible material;

What is diffraction?,

B) A seismic wave is bent when it passes by a curved surface.;

Why do seismic waves follow strongly curved paths as they move through the interior?,

C) Their velocities are changed because of increasing pressure with depth.;

A relatively weak layer in the Earth due to temperature is known as the ________.,

D) asthenosphere;

Where is the thinnest continental crust in North America?,

D) Basin and Range region;

Where is oceanic crust generated?,

D) Along divergent plate boundaries;

The ________ is a seismic boundary between the crust and the mantle where there is a dramatic increase in seismic wave velocity., ;

A) Moho boundary

The ________ layer is thought to have large variations in composition as well as temperature.,

D";

Which layer or layers of the interior are believed to have convection cells?,

D) Mantle;

Which layer is thought to be the birthplace of deep mantle plumes?,

D" layer;

The inner core is believed to rotate independently from the outer layers of Earth. Why is this possible?,

D) The inner core is separated from the mantle by the liquid outer core and can spin freely.;

Where is the highest rate of heat flow escaping the Earth's interior?,

C) At mid-ocean ridges;

________ is a technique to view three-dimensional changes in composition and density by using seismology.,

C) Seismic tomography;

How is the shape of Earth affected by its rotation?,

B) The equator is further from the center of Earth than the poles.;

Which of the following materials would cause the greatest gravity anomaly?,

D) Metallic ore;

A ________ occurs when an iron-rich fluid in the core is electrically charged and flowing, which generates a magnetic field.,

D) geodynamo;

________ are responsible for the heat generated in the interior today.,

A) Nuclear reactions;

Why is conduction not an efficient way to move heat through most of the Earth?,

C) Rocks are poor conductors of heat.;

What physical property of continents makes them difficult to subduct?,

A) Low density;

Which process is responsible for Earth's magnetic field? In which layer does this process occur?,

D) Convection; outer core;

Which of the following factors contributed toward the early increase in temperature in the Earth's interior?,

A) Radioactive decay and impact from planetesimals;

If the outer core is cooler than the inner core, why is it in a liquid state?,

D) It is under less pressure than the inner core..

The measurement of ocean depth and the topography of the ocean floor are known as ________.,

A) bathymetry;

Which of the following groups contains all three major topographic provinces oceanographers use to define the seafloor?,

A) Continental margins, mid-ocean ridges, and deep-ocean basins;

What are the two types of continental margins?,

A) Passive and active;

Which of the following is associated with an active continental margin?,

C) Convergent boundaries;

Which of the following is associated with a passive continental margin?,

D) No tectonic boundaries nearby;

Which region is surrounded by an active continental margin?,

D) Pacific Ocean;

Which of the following scenarios would likely result in the development of a passive continental margin?,

C) Continental blocks rifting apart and becoming separated by seafloor spreading;

The continental shelf is composed of which material(s)?,

C) Granitic crust covered with sedimentary rocks;

Although many areas of the continental shelves are relatively featureless…?,

D) The sea level dropped during the last glacial episode…;

Which of the following will mark the furthest extent of a continent?,

B) The crest of the continental slope;

What is the definition of turbidity current?,

C) Fast-moving water created by density differences;

Which part of a passive continental margin is built up by repeated deposition from turbidity currents?,

B) Continental rise;

Submarine canyons… created ________.,

A) by rivers during the ice age;

What is the definition of subduction erosion?,

D) Sediment and rock are scraped off the bottom of an overriding plate…;

Where is the deepest place on Earth?,

D) Challenger Deep;

Along which tectonic boundary are deep-ocean trenches found?,

B) Convergent;

Volcanic island arcs are found near which features?,

C) Deep-ocean trenches;

What is the source of flood basalts?,

D) The melting of the head of a mantle plume;

Volcanic islands such as Hawaii form as a result of ________.,

C) mantle plumes;

Submarine volcanoes… are called ________.,

D) seamounts;

Where do rift valleys form along ocean ridges?,

A) Along the axis of some ridge segments…;

What rock would you expect at a mid-ocean ridge?,

A) Basalt;

What generates magma for seafloor spreading?,

C) Decompression melting;

Which is NOT found at mid-ocean ridges?,

A) Deep submarine trenches;

Oceanic crust composition?,

C) mafic; ultramafic;

Sheeted dike complex is layer ______.,

C) 3;

Which is NOT a continental rift?,

B) Appalachia, United States;

Thermal springs known as ________.,

D) black smokers;

Process near black smokers?,

B) Hydrothermal metamorphism;

Why do mantle plumes concentrate under supercontinents?,

C) A large landmass acts as an insulating blanket…;

Most mountain ranges are the result of ________ stress.,

B) compressional;

Increasing downward force is called ________.,

B) Isostacy;

Subduction angle influence?,

A) The steeper the angle, the closer the arc…;

Where are young mountain belts?,

B) Along the margins of the continent;

Region with undeformed sediments?,

D) Forearc region;

Order of subduction features?,

D) Deep-ocean trench, forearc region, volcanic arc, back-arc region;

What influences trench depth?,

A) Temperature and density of the plate;

Cascadia lacks trench because?,

B) Shallow angle + sediment infill;

Subduction angle vs forearc basin?,

A) Shallow angle → wide basin;

Source of forearc sediments?,

A) Continental sediments and pyroclastic materials;

Back-arc basin develops?,

B) Rift valley;

How does extension form?,

A) Trench rolls back…;

Example of island arc?,

B) Aleutian Volcanoes;

Arc forms on ________.,

A) continental plate; magma;

Sediment basin between wedge and arc?,

A) forearc basin;

Divergent boundary feature?,

C) A rift zone;

Example of forearc remnant?,

A) Great Valley, CA;

Accretionary wedge?,

A) Sediments scraped off subducting plate;

Arc magma composition?,

B) Intermediate or felsic;

Transported crust fragment?,

D) Terrane;

Accreted terranes location?,

C) California;

What is a suture?,

A) Zone where continents are welded;

Rocks during India-Asia collision?,

A) Displaced to Southeast Asia;

Appalachian order?,

B) Taconic, Acadian, Alleghanian;

Taconic Orogeny?,

A) Volcanic arc thrust over continent;

Western North America geology?,

A) Accreted microcontinents;

Fault-block mountains?,

A) Formed by extension and normal faulting;

Region with parallel ranges?,

C) Basin and Range Province;

Isostatic adjustment example?

, C) Hudson Bay rebound;

Why mapping terranes is difficult?,

C) Distinct but highly deformed;

Downslope movement of material?,

B) Mass wasting;

Sudden large movement?,

D) Rockslide;

Most likely large-scale mass wasting?,

A) Rocky Mountains;

NOT a factor?,

B) Geologic age;

Valleys if only water?,

D) V-shaped valleys;

Catastrophic landslides occur?,

B) Steep young mountains;

Controlling force?,

B) Gravity;

Final initiating cause?,

A) trigger;

Oversteepened slope cause?,

D) Construction of buildings;

Angle of repose?,

C) Steepest stable angle;