Geologic Time Scale

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What is the Geologic Time Scale?

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The Geologic Time Scale is a record of the history of the Earth preserved in rocks and fossils.

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What are the main divisions of the Geologic Time Scale?

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The main divisions are eons, eras, periods, epochs, and ages.

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What is an eon in the context of the Geologic Time Scale?

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An eon is the largest division of geological time, lasting billions of years.

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What is the significance of the Precambrian era?

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The Precambrian era accounts for about 88% of Earth's history and includes the formation of the Earth and the earliest life forms.

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What major event marks the beginning of the Paleozoic era?

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The Cambrian Explosion, which saw a rapid diversification of life.

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What is the Mesozoic era known for?

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The Mesozoic era is known as the age of reptiles, including 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 is the Cenozoic era known for?

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The Cenozoic era is known as the age of mammals and birds.

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What are fossils and why are they important in geology?

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Fossils are the preserved remains or traces of ancient organisms, important for understanding Earth's history and the evolution of life.

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What is radiometric dating?

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Radiometric dating is a method used to date materials by measuring the decay of radioactive isotopes.