Phanerozoic Eon


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Related to Phanerozoic Eon: Paleozoic era, Paleogene Period

Phanerozoic Eon

 

a major interval of time, encompassing the Paleozoic, Mesozoic, and Cenozoic eras of the earth’s geologic history. The total duration of the Phanerozoic eon was 570 million years. The eon was delineated in 1930 by the American geologist G. Chadwick, who divided all of geologic history into the Cryptozoic and Phanerozoic eons.