Geo Chapter 5

Which of the following statements about the future position of plate boundaries is plausible? Choose all that apply.

- Australia will move northward toward Asia. - About 250 million years from now, the Atlantic Ocean basin will close due to subduction.

Which of the following is an example of a divergent plate boundary? Choose all that apply.

- East Pacific Rise - Mid-Atlantic Ridge - East African Rift

Which of the following are features of a divergent plate boundary? Choose all that apply.

- a rift valley - an oceanic ridge

Which of the following is evidence of continental drift? Choose all that apply.

-Coal deposits have been found in North America. -Glossopteris fossils have been found on Antarctica and Australia. -Matching rock units are found in Brazil and Africa.

Which of the following accurately describes how lithospheric plates move?

As an edge of a plate sinks into the asthenosphere, it pulls the trailing plate along.

a subdivision of the mantle below the lithosphere and is composed of easily deformed rock

Asthenosphere

a theory that was replaced by the plate tectonics theory, that the continents are rafted about

Continental Drift

as tectonic plates continye to pull apart the curst the broken crustal fragments sinks making a depression called

Continental Rift

Mountains formed in part by Igneous activity associated with the subduction of oceanic lithosphere beneath a continent

Continental Volcanic Arcs

the transfer of heat by the movement of mass or substance (only in liquid form)

Convection

two plates moving together causing one slab to descend beneath a plate

Convergent plate boundary

the temperature above which a mterial loses its magnetization

Curie point

a narrow enlarged depression on the floor of the ocean

Deep Ocean trenches

a region where the rigid plates are moving apart, creating mid ocean ridges

Divergent Plate Boundary

a linear zone of irregular topography on the deep ocean floor that follows transform faults and their inactive extentsions

Facture Zone

an area of Volcanoism high heat and crustal uplifts that is a few kilometer across

Hot Spot

a chain of volcanic structures produced as a lithosphere plate moves over a mantle plume

Hot Spot Track

the rigid out layer of Earth, including the crust and upper mantle

Lithosphere

a constant motion with respect to one another, including the crust and uppermost mantle

Lithosphere Plate (Plate)

a change in the polority of Earth's magnetic filled that occurs over time intervals of roughly 20,00 years

Magnetic Reversal

the history of magnetic reversals through geologic time

Magnetic time scale

a sensivtive instrument used to measure the intensity of Earth's magnetic feild

Magneticometer

Cylindrically shaped upwelling of hot rock is located under Hawaii

Mantle plume

a magnetic filled that is the same as that which exists at present

Normal polority

rifts at the crests of ridges represent divergent plate boundaries (longest topographic feature on Earth)

Oceanic ridge system

Rocks formed years age contain a "record" of the direction of the magnetic poles at the time of their formation

Paleomagnetism

In the Mesozoic era (200 million years age) a supercontinent began to break part and form present day landmasses

Pangaea

generate molten material to mix with unmelted mantle rock

Partial Melting

a magnetic filled opposive that which exists at present

Reverse polority

it involves the oceanic lithosphere sliding down the oceanic ridge under the pull of gravity

Ridge push

a region of Earth's curst along which divergence is taking place

Rift Valley

the process of producing new seafloor between two diverging plates

Seafloor Spreading

a plate motion in which cool, dense, oceanic, crust sinks into the mantle and "pulls" the trailing lithosphere along

Slab Pull

a region where the rigid plates are moving apart

Spreading center

a large landmass that contains all or nearly all of the existing continents

Supercontinent

Which of the following pieces of evidence supports the plate tectonic theory?

The stripe patterns of high- and low-intensity magnetism are mirror images on both sides of an oceanic ridge.

proposing that Earth's outer shell consists of individual plates that interact in various ways and thereby produce Earthquakes, volcanos, mmountains, and the crust itself

Theory of plate tectonics

two plates slide past one another without creating or destroying lithosphere

Transform Plate boundary

a chain of volcanic islands where active subduction of one Oceanic plate beneath another

Volcanic Island Arc

Which of the following statements by Alfred Wegener led to the ultimate rejection of continental drift as a hypothesis about continental movement?

Wegener suggested that the continents broke through thinner oceanic crust as they migrated over time.

Which of the following is a feature of a continental-continental convergent plate boundary?

slivers of oceanic crust in a large mountain range

Which of the following is an example of a transform plate boundary?

the San Andreas Fault