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Questions and Answers
What is the main reason for the disappearance of Banded Iron Formations (BIFs) from the rock record at around 1.9 Ga?
What is the main reason for the disappearance of Banded Iron Formations (BIFs) from the rock record at around 1.9 Ga?
- Massive cap carbonates covered the BIFs
- The alternation between oxic and anoxic ocean waters ceased (correct)
- The inclination angle of the BIFs changed
- The BIFs were affected by dropstones
What does natural remnant magnetism (NRM) of a rock or sediment preserve?
What does natural remnant magnetism (NRM) of a rock or sediment preserve?
- Paleo latitude at the time of formation (correct)
- The presence of cap carbonates
- The inclination angle of the Earth
- Climate conditions at the time of formation
How can one determine if the magnetism of a rock has been reset?
How can one determine if the magnetism of a rock has been reset?
- Check for the presence of cap carbonates
- Examine magnetism in folded rock layers (correct)
- Measure the presence of dropstones
- Analyze the inclination angle of the rock
What does the presence of dropstones indicate about a region's latitude?
What does the presence of dropstones indicate about a region's latitude?
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How could warm water carbonates form directly on top of glacial deposits?
How could warm water carbonates form directly on top of glacial deposits?
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Why were the oceans swinging between oxic and anoxic?
Why were the oceans swinging between oxic and anoxic?
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What caused the axial tilt during the Neo Proterozoic?
What caused the axial tilt during the Neo Proterozoic?
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How can warm water deposits overlie glacial deposits?
How can warm water deposits overlie glacial deposits?
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What caused the axial 'un-tilt'?
What caused the axial 'un-tilt'?
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How could ice form at the equator?
How could ice form at the equator?
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Why was ocean productivity reduced?
Why was ocean productivity reduced?
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What about banded iron formations, cap carbonates, and light carbon isotopes?
What about banded iron formations, cap carbonates, and light carbon isotopes?
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