Geological Timescale

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What is the Geological Timescale?

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A system used by geologists and paleontologists to describe the timing and relationships of events in Earth's history.

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What does the law of superposition state?

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In undisturbed rock layers, the oldest layers are at the bottom and the youngest are at the top.

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What is the Precambrian Era?

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The longest geological era, covering about 88% of Earth's history, before the Cambrian period.

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When did the Mesozoic Era occur?

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Approximately 252 to 66 million years ago, known as the age of dinosaurs.

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What significant event marks the end of the Mesozoic Era?

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The mass extinction event that led to the extinction of the dinosaurs.

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What are fossils?

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Remains or traces of ancient organisms preserved in rock.

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What is the significance of the Cambrian Explosion?

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A rapid diversification of life that occurred around 541 million years ago, leading to the emergence of many major groups of animals.

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What is a geological timeline?

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A visual representation of Earth's history, showing the timing of major geological and biological events.

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What is the Cenozoic Era known for?

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The era of recent life, starting 66 million years ago, characterized by the dominance of mammals and birds.

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What is a mass extinction event?

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A period in which a significant percentage of all life on Earth becomes extinct in a relatively short time.