Chapter 18: End Permian Mass Extinction

Question 1

Why do we use Uranium isotopes to help date extinctions/craters?

Answer 1

because it decays along a well known time path to Pb

Question 2

What was Pangea like at this time?

Answer 2

• Dry winds, hot summers and cold winters
• Density of populations were decreasing
• Since continents were closer together, this eliminated swamp areas and biodiversity

Question 3

What was the 1st flood basalt event like?

Answer 3

Little one over a plume beneath China

Question 4

What was the 2nd flood basalt event like?

Answer 4

One of the largest volcanic events ever developed over a super plume in the Siberia region

Question 5

What percent of Siberian eruptions were explosive?

Answer 5

20% - potentially putting large amounts of sulphur aerosols into the to atmosphere
– CO2= global warming

Question 6

Ideas with value that caused the Permian mass extinction?

Answer 6

Asteroid impact

-Direct evidence is missing (No Crater) but there is indirect evidence such as tektites, and shocked mineral grains

Question 7

What can we conclude about the emissions emitted form the Siberian traps at this time?

Answer 7

Large volumes of CO2 were emitted but not enough to cause a mass extinction

Question 8

What happens to oxygen when the ocean waters get warmer?

Answer 8

The less oxygen gets dissolved and the slower the flow of the oceans.
- bottom water become strongly anoxic

Question 9

What does a 12C isotope mark in ocean waters?

Answer 9

• It marks rotting organisms

- - rotting uses a lot of oxygen making the environment anoxic

Question 10

What would happen to methane clathrates if oceans had warmed up enough?

Answer 10

Clathrates would break down releasing methane gas into the ocean and thus into the atmosphere