Phanerozoic Eon


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Related to Phanerozoic Eon: Paleozoic era, Paleogene Period
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

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.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.