Geologic Time Scale

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What is the Geologic Time Scale?

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The Geologic Time Scale is a system used by geologists and paleontologists to describe the timing and relationships of events in Earth's history, including the history of rock layers and fossils.

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What significant event occurred during the Oligocene Epoch?

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The Oligocene Epoch is marked by the dominance of mammals, following the extinction of dinosaurs.

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What is Precambrian Time?

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Precambrian Time is the long span of time that begins geologic time, covering approximately 88% of Earth's history before the Cambrian Period.

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Which era saw the formation of Pangaea?

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The Paleozoic Era saw the formation of Pangaea, a supercontinent that existed during the late Paleozoic and early Mesozoic eras.

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What are the main reasons for climatic contrasts between 700 million and 600 million years ago?

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Reasons include changes in ocean circulation, fluctuations in carbon dioxide concentrations, and changes to the output of the Sun.

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What is the significance of the Cambrian Period?

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The Cambrian Period is significant for the 'Cambrian Explosion,' a rapid diversification of life forms and the appearance of many major groups of animals.

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What does the term 'Mesozoic' refer to?

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The Mesozoic Era is known as the 'Age of Reptiles,' characterized by the dominance of dinosaurs and the emergence of mammals and birds.

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What is the difference between the Paleozoic and Mesozoic eras?

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The Paleozoic Era is known for the development of early life forms, including fish and amphibians, while the Mesozoic Era is known for the dominance of dinosaurs.

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What is the Phanerozoic Eon?

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The Phanerozoic Eon is the current eon in the geologic time scale, beginning about 541 million years ago and characterized by abundant fossil evidence.

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What are fossils?

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Fossils are the preserved remains or traces of ancient organisms, providing important information about past life and environments.