Lecture 9: Zealandia

Question 1

What are the Two types of continental margins?

Answer 1

1. Active margins:
2. Passive margins:

Question 2

Describe an active continental margin:

Answer 2

• Continental margins that coincide with plate boundaries
• e.g. subduction zones (convergent boundaries)
• Zealandia was part of an active margin prior to 100 Ma

Question 3

Describe a passive continental margin

Answer 3

• Continental margins that are
  far from plate boundaries
• e.g. margins of Atlantic ocean
• Zealandia was surrounded by
  passive margins after breakup from Gondwana at 100 Ma

Question 4

Describe Zealandias history:

Answer 4

• Zealandia part of active continental
  margin before 100 Ma
• Continental rifting begins ~100 Ma
• Initial separation of Zealandia from Gondwana 83 Ma
• Separation of Zealandia from Australia at 62 Ma

New oblique convergent plate boundary
(combination of convergence and transform motion) (24 Ma)

This plate boundary caused uplift, accretion and created present day NZ