Zealandia

Question 1

When did it become Zealandia

Answer 1

• Late Mesozoic when rifted from Australia

- Sedimentary, tectonic and fossil records are our own (fossils can be globally)

Question 2

Cretaceous Rifting

Answer 2

• Bunch of terrain amulgated together from Gondwana and drifted away

Question 3

Late Oligocence c.25 Ma

Answer 3

• Most of land area is reduced. Any land material left was low topography.
• Some active faulting - large boulders deposited in marine - only faulting an island so not a lot of land mass (instead of a mountain range)
• Currents coming from South to North, pushing cold water inland
• Oligocene is where we get the most calcareous rocks - limestones

Question 4

Top Cretaceous c. 65 Ma

Answer 4

• Parts of Zealandia was above water

Question 5

Late Miocene c. 10 Ma

Answer 5

• There is lakes with late Oligocene, early Miocene sediment - can’t get lakes in the ocean so Zealandia probably wasn’t submerged in Oligocene
• Must have land to support Moas and Fresh water worms
• Alpine fault comes in late Miocene - uplift and start to deform the Zealandia continent - starts to kill off the limestone and goes to more siliclastic settings
• Still have limestone but have to have a way to keep the dirt out