Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso

Proterozoic Aeon

  • Felix M. Gradstein
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_1291-3

Definition

The Proterozoic is the youngest of the two great divisions of the Precambrian and ranges from 2,500 to 542 Ma.

Overview

The Proterozoic Eon begins at 2.5 Ga, which approximately marks the time when oxygen from cyanobacteria began to dramatically change the composition of the Earth’s atmosphere and oceans and when complex one-celled life (eukaryotes) evolved from simple cells (prokaryotes). The Proterozoic is subdivided into ten periods, generally of 200-Myr duration, grouped into three eras. The poetic names for these periods (see International Stratigraphic Chart: www.stratigraphy.org) are derived from the larger-scale tectonic or sedimentary features that occurred within each period. For example, the Siderian Period (2.5–2.3 Ga) is named from the banded iron deposits (sideros = iron) that peaked within that interval. The lack of a diverse and well-preserved fossil record, the sparse volume of supracrustal rocks, a variable degree of metamorphism and tectonic disturbance,...

Keywords

Banded iron formation Eukaryotes Geological timescale Great oxygenation event Precambrian 
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References and Further Reading

  1. Ogg JG, Ogg G, Felix M (2008) Gradstein. The concise geologic time scale. Cambridge University Press, Cambridge, p 177Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.University of OsloBlindemNorway