Plate Tectonics

The place where three plate boundaries meet is referred to as a(n) -- junction.

Triple

When two oceanic plates converge, some magma erupts under the ocean, forming volcanoes that may rise above the sea. These volcanoes can form a curved ________.

Island Arc

Mid-oceanic ridges are ___________.

found at divergent plate boundaries considered spreading centers

Glacial evidence in _________ continents that are too warm for glaciers in their current position is evidence of continental drift.

southern

boundaries are formed when plates come together.

Convergent

Including the one that was just recently discovered, how many continents are there on Earth?

8

Where is the thickest sediment in the ocean located? (Select all that apply)

Along continental margins Near the mouths of rivers Where the oceanic crust is old

Rank the stages of continental rifting with the first stage on left and the last stage on the right.

Ascension of magma causes uplift of the crust. Stretching of the crust causes crustal blocks to drop into faults, forminig a rift. Rifting splits the continent into two; a narrow ocean forms as seafloor spreading takes place. Seafloor spreading increases the size of the ocean basin as rifting continues.

Match the image letter to the correct seafloor feature found adjacent to South America

B = Deep ocean trench A = Volcanic Island Cluster C = Island Arc D = Mid-Atlantic Ridge

The location of earthquakes is a better guide to plate-- than the location of volcanoes.

Boundaries

The primary factor controlling the -- of a region is the thickness of the underlying crust.

Elevation

Curved island arcs and linear islands chains are very similar in their character and formation

False

For a plate to move, the driving forces must exceed the -- forces.

Frictional

Which of the following IS NOT a characteristic of continental hot spots?

Have elevations lower than the surrounding land areas

__________ evolution begins with doming and ends with the formation of a new continental margin and a new ocean formed by seafloor spreading.

Hot Spot

Oceanic plateaus form from basaltic volcanic originating from ______.

Hot Spots

According to plate tectonics, oceanic crust forms from upwelling magma that spreads outward from a mid-ocean ridge. Which of the following statements support this? (Select all that apply)

If this is true, the oldest basalt should be the farthest from the mid-ocean ridge. If this is true, the thickest sediment cover should be farthest from the mid-ocean ridge.

Mid-ocean ridges are broad, symmetrical ridges that cross -- basins.

Ocean

Which of the following are characteristics of continental rifting? (Select all the apply).

Rifting begins with a broad uplift as magma ascends. If rifting continues, the continent can be slpit into two pieces. Stretching of the crust causes crustal blocks to drop down

Rank, in order, the evolution of a continental hot spot, with the first part of the process at the left and the final result at the right.

Rising mantle material first encounters the base of the lithosphere Domal uplift forms at the surface, stretching the crust Rift arms are formed by faulting, and eruptions of lava being Complete rifting of the continent occurs along two arms of the rift, while the third arm becomes inactive Seafloor spreading continues and a passive margin is created as the mid-ocean ridge moves farther out the sea.

Select the five oceans of Earth from the list below.

Southern, Indian, Atlantic, Artic, Pacific

Which of these best describes the location of the core within Earth?

The core is located in the central zone of Earth, beneath the mantle.

Which of the following statements are accurate about volcano distributions on Earth? (Choose all that apply)

Volcanism occurs along mid-ocean ridges., There is a large volcanic belt along the west coast of North and South America, Many volcanes along the edge of the Pacific Ocean are associated with earthquakes

cover 71% of Earth's surface

Water

Island -- are curving chains of mostly volcanic islands that cross the seafloor.

arcs

Intense geologic activity is concentrated at plate _____.

boundaries

Tectonics are processes that ____________.

deform the crust and mantle

Lava erupting from a rift of two oceanic plates pulling apart __________.

encounters seawater and is immediately cooled

Oceanic plates subduct beneath continental plates when the two plates converge because ____________.

oceanic plates are more dense and continental plates are more buoyant

There are two main types of crust on Earth; they are ______ and __________.

oceanic, Continental

The lithosphere is ___________.

the rigid portion of Earth (crust and upper mantle)

Match the image letter with the description of its place in the evolution of a continental hot spot.

B = Mantle material rises, the crust heats up, and a broad, domal uplift forms on the surface, which stretches the crust. C = Three rifts, bordered by normal faults, are well developed; the formed basins contain lacks; volcanism has begun. A = Complete rifting of the continent along two arms of the rift, new margin created and seafloor spreading started; failed rift becomes less active D = Mid-ocean ridge moved father out to sea; contiental margin subsides and is covered by marine sediment on the new continetal shelf; failed rift has rivers and a delta.

A ____________ can form from a divergent boundary that forms within a continent.

Continental Rift

Some continents continue outward from the shoreline under the seawater. These submerged benches are called-- shelves.

Continental Shelves

The yearly rate of tectonic plate movement is best measured in _________.

Centimeters

When two continental masses converge, it is referred to as a continental

Collision

Place the layers of Earth in order beginning with the layer with the highest elevation at the left and ending with the layer making up the center at the right.

Continental Crust, Oceanic Crust, Upper Mantle, Lower mantle, Outer Core, Inner Core

In regard to how Earth's composition changes with depth, match the Earth's layer with its correct description

Continental Crust= Has a composition similar to granite Oceanic crust= Has a composition similar to basalt Upper mantle= Mostly composed of the green mineral olivine Core= Believed to consist of metallic iron and nickel.

When two ocean plates come together, a _____ is formed.

Convergent Boundary

A magma-filled fissure under pillow basalt is referred to as a _________.

Dike

The ____________ of two oceanic plates results in mid-ocean ridges.

Divergence

The rocks that make up the new oceanic crust at a mid-ocean ridge are all __________ and are rich in magnesium and iron. (Select all that apply).

Igneous Mafic

The process of plate tectonics circulates materials between the asthenosphere and the

Lithosphere

The asthenosphere is part of the Earth's

Mantle

How many times did Earth's magnetic field switch in the last 10 million years?

Many-more than 40 times

Which of the following statements are true about characteristic geologic features with respect to their locations on Earth?

Mid-ocean ridges and their fracture zones encirlce much of the globe. Seamounts can be part of island arcs. Continents and oceans have elevated areas called plateaus. Smooth regions of the ocean floor are called abyssal plains. Continental shelves are extensions of continents beneath the oceans.

beneath the ocean that do not reach the surface are called seamounts. They may be worn-down islands or may be formations that never have been tall enough to break the water's surface.

Mountains

Summarize the formation of the Atlantic Ocean by putting the following into correct order with the first stage on the left.

North America, South America, Europe, and Africa were all part of the same supercontinent The crust underneath the supercontinent was uplifted by underlying magma moving toward the surface. The continental crust began to stretch, and a continental rift was formed. The rift split the supercontinent to form a narrow ocean basin. The ocean basin continued to widen through seafloor spreading.

Oceanic fracture zones are cracks and steps that cross the seafloor and run mostly at right angles to --- ridges

Ocean

A(n) _________ zone is a step in the elevation of the seafloor that is found extending outward from most transform faults.

Oceanic Fractures

The layer of Earth that behaves like a dynamo (electrical generator), producing the magnetic field, is the _______.

Outer Core

_______________ it the record of past changes in Earth's magnetic field as recorded in rocks and other materials.

Paleomagnetism

Broad, elevated regions, whether they are on land or under the ocean, are called ______.

Plateaus

GPS and lasers are used to directly measure the motion and direction of tectonic -- on Earth.

Plates

At a black smoker, which types of organisms listed below would you expect to find? (Select all that apply)

Red tube worms White crabs Bacteria that use sulfur as an energy source

Basaltic magma forms the rock at the mid-ocean

Ridge

Earth's tectonic plates move because of slab pull, mantle convection, and _________ push.

Ridge

Which pieces of evidence supported Wegener's hypothesis of continental drift? (Choose all that apply).

Souther continental landmasses seem to fit together like puzzle pieces. Similar rocks and geologic structures exist in South America, Africa, and Antarctica Fossils of animals and plants that existed more than 150 million years ago are present on several continents that are now divided by ocean. Glacial evidence exists in places that are now close to the equator, and the direction of glacial movement indicates the continents were once joined.

Which of the following are characteristics of slab pull? (select all that apply)

Subducting oceanic lithosphere is denser than asthenosphere Subducting plates move faster than the nonsubducting plates. Gravity is a major force in slab pull.

The geologic process that results in the Ring of Fire is known as

Subduction

The process of one plate sliding beneath another plate is called _______.

Subduction

plates are composed of lithosphere and move around on the asthenosphere.

Tectonic

Which of the following are examples of locations formed by the convergence of two oceanic plates? (Select all that apply.)

The Andes of South America The Aleutian Islands of Alaska Java in Indonesia

Which of the following statements describe black smokers? (Select all that apply)

They form along mid-ocean ridges They form mineral deposits rich in copper and zinc. They form sulfide-rich chimneys.

Sediments near the mid-ocean ridges tend to be _____.

Thin

With respect to thickness, the oceanic crust is --- than the continental crust.

Thinner

A fault that accomodates the horizontal movement of one tectonic plate past another is a -- fault

Transform

What specific type of plate boundary combines with spreading centers to form a zigzag pattern on the seafloor, often linking different types of plate boundaries?

Transform

The surface of Earth is notable for many geologic features including ________. (Choose all that apply)

Under sea trenches, intricate coastlines, beautiful valleys, dramatic mountains

Which of the following are examples of oceanic-continental plate convergence boundaries?

Volcanoes of southern British Columbia Volcanoes in the Andes Mountains of South America Volcanoes of the Cascade Range in the U.S. Pacific Northwest