L6 - Dynamic Planet - The Lithosphere

Question 1

What are the two sections of a fault called and how would you hell them apart?

Answer 1

• Hanging wall block and footwall block
• From the perspective of someone in the fault plain, the hanging wall block is at your head and the footwall block is at your feet.

Question 2

Types of fault

Answer 2

Normal fault
Reverse and Thrust fault
Strike-Slip fault

Question 3

Characteristics of an normal fault

Answer 3

• Occur in areas of extension e.g. Rift Valleys
• Hanging wall blocks moves down relative to footwall blocks
• Fault plain relative vertical

Question 4

Characteristics of Reverse and Thrust faults

Answer 4

• Occur in areas of compression and collision
• Hanging wall move upwards along fault plain relative to footwall block
• Reverse faults: >35• steeper
• Thrust faults:

Question 5

What would thrust faults tend to look like?

Answer 5

• ‘ripples’, a series of successive thrust faults which each one acting as the hanging wall of the latter

Question 6

Characteristics of a Strike-Slip fault

Answer 6

• Occur near transform faults
• Tend to vertical
• Defined by relative motion of far side block to the observer e.g. Right-moving or left moving

Question 7

Give an example of the lithosphere behaving in an elastic fashion?

Answer 7

Lithosphere deformation around hotspot areas - Lithosphere flexes around weight of igneous rock