Rise Of Oxygen

Question 1

What process causes the long term removal of oxygen from the atmosphere

Answer 1

Oxidative weathering of ancient organic carbon

Question 2

Features of oxygenation state during Proterozoic eon

Answer 2

Oxidising atmosphere, oxygenated surface ocean, anoxic deep ocean

Question 3

What was the oxygenated state of the earth after photosynthesis but before the great oxidation

Answer 3

Reducing atmosphere, oxygenated surface ocean, anoxic deep ocean

Question 4

Evidence of the great oxidation

Answer 4

The disappearance of mass independent fractionation of sulphur isotopes

Question 5

What increased rates of oxygenation

Answer 5

Plants colonising the land, would have increased weathering to get phosphorus, this would be washed out to sea when plants died which increased primary productivity of the ocean

Question 6

Example of an electron donor for photosynthesis

Answer 6

H2O

Question 7

When was the earths second oxygenation event

Answer 7

600-400 Ma

Question 8

When was the great oxidation event

Answer 8

2.4-2.3 Ga