Structure of the Lithosphere, Plate Tectonics and Rock Formation

Question 1

Crust

Answer 1

The outer layer with a thickness of 70 km.
Two types of crust: oceanic and continental.

Question 2

Mantle

Answer 2

This is a very thick layer extending 2900 km. Mostly dense and solid although there is a densely thin-semi-liquid layer in the upper mantle.

Question 3

Core

Answer 3

Can be divided into the liquid outer core and an iron-rich solid inner core. Temperatures here reach 5500 C. The centre of the Earth’s core is 4600 km below the surface.

Question 4

What is the earths crust made up of?

Answer 4

Several large sections called Plates about 100 km thick.

Question 5

Where are these plates located?

Answer 5

The crust and the upper part mantle. The plates rest on the semi-liquid layer in the upper mantle which helps them to move

Question 6

Name the plates

Answer 6

Adriatic
Aegean
Turkish
Juan de Fuca
Cocos
Caribbean Plate
Philippines
Iranian
Arabian

Question 7

Where are earthquakes concentrated?

Answer 7

At the edges of the plates (boundaries) pressure is built up and suddenly released causing earthquakes.

Question 8

The four types of plate margins?

Answer 8

Divergent
Convergent
Collision
Transform

Question 9

What causes plates to move?

Answer 9

Convection currents. This occurs when heat spreads out and flows towards the surface, forming large convection (heat) cells.

Question 10

Evidence of plate tectonics?
Evidence to support continental drift?

Answer 10

1. Identical rocks in South America and West Africa
2. Continents fit together like a jigsaw puzzle
3. Identical species of land-based fossils found in continents that are today separated by wide oceans
4. Patterns of earthquakes, volcanoes, mountain ranges and deep ocean trenches provide evidence of the precise location of active plate boundaries.

Question 11

Divergent boundary or Constructive margin

Answer 11

Two plates moving from each other
*Volcanoes
*Underwater volcanoes
*Range of mountains called mid-oceanic ridge

Question 12

Convergent boundary or Destructive margin

Answer 12

Two plates moving towards each other
One of the plates is made of dense oceanic crust causing it to dive underneath the other plate to form a subduction zone. Immense heat destroys the subducting plate.
*Earthqaukes
*Volcanoes
*Fold mountains

Question 13

Collision margin

Answer 13

Plates of the same density collide with no subduction
*Earthquakes
*Fold mountain
*No volcanoes

Question 14

Transform boundary

Answer 14

Sliding alongside each other.
*Earthquakes

Question 15

The types of plate margins and landforms associated with the Caribbean plate

Answer 15

On the northern edge of the Caribbean plate, there is a transform boundary between the Caribbean plate and the North American plate.

At the western boundary of the Caribbean plate, oceanic crust making up the Cocos plates is subducting beneath the Caribbean plate forming a zone of volcanoes, earthquakes and fold mountains in South America

The southern boundary of the Caribbean plate is part convergent and part transform. Earthquakes do not occur here as often as in the other Caribbean plate boundaries.

To the east of the Caribbean plate, an active convergent boundary exists between the south american plate and the Caribbean plate. The subducting south american plate is responsible for a chain of mostly volcanic islands known as the lesser Antilles

Question 16

What is an Earthquake?

Answer 16

An earthquake is a sudden violent shaking of the ground

Question 17

Features of an Earthquake?

Question 18

What is a volcano?

Question 19

What is the ring of fire?

Question 20

What are hot spots?

Question 21

What are island arcs and ocean trenches?

Question 22

What are fold mountains?

Question 23

What are major faults?

Question 24

Difference between intrusive and extrusive volcano features?

Question 25

Types of intrusive volcanic features?

Question 26

Types of extrusive volcanic features?

Question 27

Types of lava?

Question 28

What are intrusive volcanic landscapes like?

Question 29

What are extrusive volcanic landscapes like?

Question 30

What is the rock cycle?

Question 31

Three types of rocks?

Question 32

How are island arcs formed

Answer 32

Volcanic islands are formed at convergent plate boundaries where the south american plate is subducting beneath caribbean plate.

island arcs formed when lines of weakness form in overlaying continetial crust and magma rising deep underground reaches the surface to form a chain of volcanoes called island arcs