geology assignment 4

Match the heat transfer mechanisms to the correct description of how heat is transported in or from the Earth: convection

warm, low-density materials rise and cool, high-density materials sink.

match the seafloor term to its correct definitions: continental rise

wedge of sediments deposited by turbidity currents that formed at the base of the slope

Put the layers of an ophiolite complex in order from top to bottom:

-(uppermost layer) deep-sea sediments or sedimentary rocks -pillow basalts -sheeted dike complex -(lowermost layer) gabbro

why do mantle plumes tend to concentrate beneath supercontinents such as Pangaea?

A large landmass acts as an insulating blanket to trap heat in the mantle.

What is a mineral phase change?

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

which plates are Baja Mexico and the city of Los Angeles is correct?

Both are located on the Pacific Plate.

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

D" layer

Which of the following best describes the pattern of heat flow through the lithosphere?

Heat flow is high where crust is being created.

Since the breakup of Pangaea approximately 165 million years ago, a new supercontinent cycle has begun with the collision of which of the following continents?

India and Asia

What is a true statement regarding the Farallon Plate?

It was an oceanic plate that used to exist between the Pacific and North American Plates

Match the heat transfer mechanisms to the correct description of how heat is transported in or from the Earth: radiation

Match the heat transfer mechanisms to the correct description of how heat is transported in or from the Earth: conduction

What happens as plates diverge at an oceanic ridge?

New oceanic crust and lithospheric mantle are generated by the cooling of molten rock upwelling from the mantle.

which of the following regions was not part of the large Southern Hemisphere continent of Gondwana?

North America

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

Rigid, less compressible material

Subduction zones surrounding the Pacific Ocean give rise to volcanoes. This area surrounding the Pacific Ocean is called the ____________

Ring of Fire

________________ are deep valleys at passive continental boundaries. They are likely carved out by ___________, which occur when sediment-laden water rapidly moves down slope.

Submarine canyons, turbidity currents

Accurately compare the Mid-Atlantic Ridge and East Pacific Rise?

The Mid-Atlantic Ridge is spreading at a much slower rate than the East Pacific Rise.

What happened to the Farallon Plate approximately 20 million years ago?

The San Andreas and Queen Charlotte Faults were established where it was subducted beneath the North American plate.

Why does the East Pacific Rise lack a rift valley?

The rate of seafloor spreading at the East Pacific Rise is very fast.

Which of the following best describes what occurs during convection?

Warmer, less dense material rises.

What role do mineral phase changes play in plate subduction?

When an oceanic slab reaches 400 km within the mantle, the mineral olivine changes to its more dense spinel structure. This increase in density helps pull the slab farther down into the mantle.

What are the features associated with a divergent boundary that is spreading quickly?

a relatively smooth swell with gentle slopes

Strike-slip faulting of the Queen Charlotte and San Andreas fault systems shows __________.

a right lateral sense of motion

match the seafloor term to its correct definitions: continental slope

a steep incline that marks the boundary between the continental crust and the oceanic crust

which of the following techniques can be used to recreate the configuration of supercontinents that existed before Pangaea?

apparently wandering polar paths

Match the layer of Earth to the compositional materials: oceanic crust

basaltic material composing the outermost layer

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

continental blocks rifting apart and becoming separated by seafloor spreading

what geologic process initiated the breakup of Pangaea approximately 165 million years ago?

continental rifting

Melt from the subducting plate rises to the surface, erupts through the crust on the overriding plate and forms __________________ on continents, or __________ in the ocean.

continental volcanic arcs, volcanic island arcs

The plate boundary in the U.S. Pacific Northwest is _____, while most of the California coast is characterized by a _____ plate boundary.

convergent; transform

how did core samples drilled from various locations in the ocean floor support the concept of seafloor spreading?

cores containing younger sediment were located closer to the ridge crest, meaning that older material is continuously being pushed away from the ridge

The Moho separates the ______.

crust and mantle

T/F: P waves cannot penetrate the outer core because it is liquid.

false

Match the layer of Earth to the compositional materials: asthenosphere

ferromagnesian silicates mostly in a ductile state

match the seafloor term to its correct definitions: abyssal plain

flat seafloor in the deep ocean

match the seafloor term to its correct definitions: continental shelf

gently sloping, submerged extension of the continent

Match the layer of Earth to the compositional materials: continental crust

granitic material composing the outermost layer

Match the heat transfer mechanisms to the correct description of how heat is transported in or from the Earth: conduction

heat flows between two materials in contact with each other.

Match the layer of Earth to the compositional materials: outer core

liquid nickel and iron with trace materials

What contains the entire ophiolite suite, in order from the mantle to the seafloor?

mantle peridotite, gabbro, sheeted dike complex, pillow lavas, deep-sea sediments

Volcanic islands such as the Hawaiian islands form as a result of ________

mantle plumes

Oceanic crust spreads at ___________, creating new crust and slowly enlarging the ocean basin.

mid-ocean ridges

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

moho boundary

match the seafloor term to its correct definitions: submarine trench

narrow creases in the seafloor that results from subduction

What two layers of the ophiolite sequence are compositionally similar, but formed in different areas with respect to the crust?

pillow lavas and gabbro

Intervals of paleomagnetic ___________ is/are characterized by the alignment of the magnetic south pole and the geographic north pole.

reversed polarity

define subduction erosion

sediment and rock are scraped off the bottom of an overriding plate and transported into the mantle by a descending plate

when contrasting the forces slab pull with ridge push,

slab pull is a result of cool, dense rock overlaying warm asthenosphere and generates most of the force for subduction, whereas ridge push is the result of the elevated position of the ridge of the far side of the slab creating a decline down which the slab slides

Match the layer of Earth to the compositional materials: inner core

solid iron and nickel with trace materials