Proterozoic Erathem

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Proterozoic Erathem

 

a complex of rocks corresponding to the greater part of Precambrian earth history, equivalent in length to several eras (more than 2 billion years). The Proterozoic has lower, middle, and upper subdivisions. In the USSR, the Upper Proterozoic is known as the Riphean.

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