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Flashcards in Types of Plate Boundaries Deck (41)
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1

what is another name for plate boundary?

plate margin

2

What are the three main types of plate margins?

divergent, convergent, transform

3

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

oceanic, continental

4

What are the sub-types of convergent plate margins?

ocean-continent, continent-continent, ocean-ocean

5

What are the two types of crust on the Earth?

continental and oceanic

6

What are the general features of the continetal crust?

- older

- more felsic (Si-rich) rocks -

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

7

What are the general features of the oceanic crust?

- younger

- more mafic (Si-poor) rocks

- more dense

- thinner (avg. 5 km)

8

Which crust, oceanic or continental, is older?

continental

9

which crust, oceanic or continental, is thicker?

continental

10

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

oceanic

11

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

when the two types of crust interact at plate boundaries

12

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

divergent

13

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

shallow, weak

14

what kind of earthquakes happen at divergent boundaries?

shallop and weak earthquakes

15

what is a divergent plate boundary?

when two plates are moving apart from one another

16

What are the two types of divergent margins?

oceanic, and continental

17

the two types of divergent margins are based on...

the types of crust that are interacting

18

Where do we commonly see oceanic divergent margins?

at mid-ocean ridges

19

What is a good example of a continental divergent margin?

African Rift Valley

20

What is a good example of a divergent margin?

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

21

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

convergent

22

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

sinks

23

The plate that sinks down is the _______ plate

subducting

24

At the ______ zone we see a deep trench form

subduction

25

What do we see at the subduction zone?

a deep trench form

26

The subduction zone creates deep _____ and _______ mountain chains

trenches, volcanic

27

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

crust

28

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

melt

29

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

magma, islands

- linear volcanic islands form along the boundary

30

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

oceanic