Geological time scale

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Geologic Time Scale
What is it?

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divides time based on significant geological and biological events, such as mass extinctions or the emergence of new species

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Eon

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is the longest unit of geological time, spanning hundreds of millions to billions

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era

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significant division of geological time, smaller than an eon but larger than a period

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Peroid

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division of geological time that is smaller than an era but larger than an epoch

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Epoch

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The smallest commonly used division, lasting millions to tens of millions of years.

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How old is Earth’s current estimated age

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Earth's current estimated age is approximately 4.54 billion years

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Paleozoic Era

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about 541 to 252 million years ago, was a transformative period in Earth's history Cambrian explosion, development of life, and development of supercontinent

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Mesozoic Era

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"Age of Reptiles," spanned from about 252 to 66 million geological, climatic, rise of dinosaurs, break up of Pangea, evolution of birds and mammals

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Know some major events/facts regarding Cenozoic Era

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66 million years ago t "Age of Mammals" due to the dominance of mammals during this time. Extinction of dinosaurs, rise of mammals, and foundation of modern continent.

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Most NW Alabama bedrock was deposited in which era and period?

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Paleozoic Era, specifically the Mississippian Period.