# Tag Info

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### Why is Earth's age given by dating meteorites rather than its own rocks?

Some background: We are able to determine the age of certain rocks and minerals using measurements of radioactive and radiogenic isotopes of certain elements. The most common are U-Th-Pb, Rb-Sr and ...
• 22.2k

### Why is Earth's age given by dating meteorites rather than its own rocks?

The answers that have been provided are correct but they're omitting the fundamental issue that explains why they are correct: When you date a rock you get the point that it solidified, not the point ...
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### What caused a fall in atmospheric oxygen about 1.9 billion years ago?

The answer might lie in aerobic respiration. This is of course only one of the many possible explanations but mitochondria (and therefore $\ce{O2}$-breathing eukaryotes) are thought to have evolved ...
• 5,278
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### Could Earth have had a greater axial tilt?

There is no evidence that Earth had a much greater axial tilt so long ago. To my knowledge, the evidence for changes in the axial tilt of the Earth is based on ocean sediment cores (see http://en....
• 12.7k
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### Why would there be no hydrocarbons in the Sveconorwegian belt?

There's a little more to it than its substantial age, but not a lot. First, a bit of background. We need a few conditions for accumulations of oil or gas: A kerogen-rich source rock that has been '...
• 10.8k

### Why is Earth's age given by dating meteorites rather than its own rocks?

Simple enough, see the meteorites formed alongside the planet, however, since the planet was pretty much a molten soup you can't date it properly, because we can only date it after it cooled down. ...
Accepted

### Can we call the Precambrian eons (i.e. Archaic and Proterozoic) eras?

It is and is not an an error depending on how it is used. They are Eons but in older literature they were also, sort of, eras as the Eons were not subdivided as they are now. Especially in literature ...
• 6,558