Proterozoic: Meaning and Definition of


Pronunciation: (prot"ur-u-zō'ik, prō"tur-), [key]
— Geol. Geol.
  1. noting or pertaining to the latter half of the Precambrian Era, from about 2.5 billion to 570 million years ago, characterized by the appearance of bacteria and marine algae; Algonkian.
  1. the Proterozoic division of geologic time or the rock systems formed then; Algonkian. See table under
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.
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