Types of Plate Boundaries

Question 1

what is another name for plate boundary?

Answer 1

plate margin

Question 2

What are the three main types of plate margins?

Answer 2

divergent, convergent, transform

Question 3

What are the sub-types of the divergent plate margins?

Answer 3

oceanic, continental

Question 4

What are the sub-types of convergent plate margins?

Answer 4

ocean-continent, continent-continent, ocean-ocean

Question 5

What are the two types of crust on the Earth?

Answer 5

continental and oceanic

Question 6

What are the general features of the continetal crust?

Answer 6

• older
• more felsic (Si-rich) rocks -

less dense (avg. 2.7 gm/cm^3 - thicker (avg. 35 km; up to 65km)

Question 7

What are the general features of the oceanic crust?

Answer 7

• younger
• more mafic (Si-poor) rocks
• more dense
• thinner (avg. 5 km)

Question 8

Which crust, oceanic or continental, is older?

Answer 8

continental

Question 9

which crust, oceanic or continental, is thicker?

Answer 9

continental

Question 10

which crust, oceanic or continental as high mafic rock content?

Answer 10

oceanic

Question 11

When does the importance of crust-type come into play?

Answer 11

when the two types of crust interact at plate boundaries

Question 12

A _______ boundary is a boundary between two plates that are moving apart from one another

Answer 12

divergent

Question 13

Since plates are moving apart at divergent boundaries it results in ______ and ______ earthquakes

Answer 13

shallow, weak

Question 14

what kind of earthquakes happen at divergent boundaries?

Answer 14

shallop and weak earthquakes

Question 15

what is a divergent plate boundary?

Answer 15

when two plates are moving apart from one another

Question 16

What are the two types of divergent margins?

Answer 16

oceanic, and continental

Question 17

the two types of divergent margins are based on…

Answer 17

the types of crust that are interacting

Question 18

Where do we commonly see oceanic divergent margins?

Answer 18

at mid-ocean ridges

Question 19

What is a good example of a continental divergent margin?

Answer 19

African Rift Valley

Question 20

What is a good example of a divergent margin?

Answer 20

Iceland, located on top of the mid-ocean ridge on the Atlantic Ocean. Iceland is actually composed of oceanic crust. it is just a big island that sprouted up from the bottom of the ocean

Question 21

When two plates move towards each other it is called a ________ margin

Answer 21

convergent

Question 22

Whenever two plates are moving towards eachother one of the plates _____ down under the under plate

Answer 22

sinks

Question 23

The plate that sinks down is the _______ plate

Answer 23

subducting

Question 24

At the ______ zone we see a deep trench form

Answer 24

subduction

Question 25

What do we see at the subduction zone?

Answer 25

a deep trench form

Question 26

The subduction zone creates deep _____ and _______ mountain chains

Answer 26

trenches, volcanic

Question 27

The plate that subducts depends on what type of _____ it is made up of

Answer 27

crust

Question 28

When oceanic crust collides with another oceanic crust one plate dips down below and starts to _____

Answer 28

melt

Question 29

As the subjecting plate of an ocean-ocean convergence melts the _____ bubbles up to to the surface and creates _____ of volcanoes

Answer 29

magma, islands

• linear volcanic islands form along the boundary

Question 30

In ocean-continent divergent margins, which crust sinks below the other?

Answer 30

oceanic

Question 31

Why does the oceanic crust sink below the continental?

Answer 31

because it is more dense

Question 32

As the ______ crust sinks it begins to melt, and the magma bubbles up through the ______ crust and creates _____ mountain chains along the coast.

Answer 32

oceanic, continental, volcanic

Question 33

What forms at the continent-continent divergent zone?

Answer 33

mountain ranges

Question 34

What is an example of a continent-continent divergent zone?

Answer 34

the Himalayas - where India is colliding into the rest of Asia

Question 35

Earthquakes are convergent margins are _____ and _____

Answer 35

deep, powerful

Question 36

what kind of earthquakes happen at convergent margins?

Answer 36

deep and powerful earthquakes

Question 37

Why are earthquakes at convergent margins deep and powerful?

Answer 37

one plate descends below another and the plates interact at vary deep depths, and because the plates are moving towards each other you can have very violent and powerful earthquakes

Question 38

Earthquakes get ______ the further from the boundary you move on the ______ plate

Answer 38

deeper, overriding

Question 39

A ______ margin’s plates are sliding past one another

Answer 39

transform

Question 40

What is an example of a transform margin?

Answer 40

the San Andreas fault

Question 41

Earthquakes at transform margins are…

Answer 41

shallow, moderately powerful, and frequent