World Library  
Flag as Inappropriate
Email this Article

Plio-Pleistocene

Article Id: WHEBN0002808389
Reproduction Date:

Title: Plio-Pleistocene  
Author: World Heritage Encyclopedia
Language: English
Subject: List of creatures in Primeval, Turkana Basin, Pleistocene, Megalodon, Parapapio
Collection: Pleistocene, Pliocene
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Plio-Pleistocene

The term Plio-Pleistocene refers to an informally described geological pseudo-period, which begins about 5 million years ago (mya) and, drawing forward, combines the time ranges of the formally defined Pliocene and Pleistocene epochs—marking from about 5 mya to about 12 kya. Nominally, the Holocene epoch—the last 12 thousand years—would be excluded, but most Earth scientists would probably treat the current times as incorporated into the term "Plio-Pleistocene" ;[1] see below.

In the contexts of archaeology, paleontology, and paleoanthropology, the Plio-Pleistocene is a very useful period to which scientists may assign the long and continuous run in East Africa of datable sedimentary layers and their contents; (for one example, see the Bouri Formation). These contents collectively present a focused view of the continuous evolution of the region's large vertebrates, especially the evolution of some African apes (hominids) to the earliest hominins; and then the development of the early humans and their toolmaking cultures. This shorter pseudo-period—from after 5 mya to about 1.5 mya—straddles the boundary between the Pliocene and the Pleistocene. Thereafter the Plio-Pleistocene formations in East Africa contain, and disclose, the genus Homo developing into archaic Homo sapiens, then to anatomically modern humans.

The term is also useful in climatology and earth sciences because the greater Plio-Pleistocene period covers the gradual but prolonged long-term cooling of the earth's atmosphere from the generally warmer temperatures of the late Oligocene / early Neogene times to and continuing through the Late Pleistocene—and indeed continuing through current times, if the present interglacial warming is considered as merely superimposed on the longer trend of cooling.[2] Beginning about 3 mya, the late Pliocene saw the start of glaciation in the Northern Hemisphere,[3] and many authors may informally use the term "Plio-Pleistocene" as a synonym for the period during which the Northern Hemisphere has been glaciated.

References

  1. ^ e.g., Anderson, R.S., Molnar, P. and Kessler, M.A., 2006, Features of glacial valley profiles simply explained, J. Geophys. Res., v. 111, F01004, doi:10.1029/2005JF000344.
  2. ^ Lisiecki, L.E., and Raymo, M.E., 2005, A Plio-Pleistocene stack of 57 globally distributed benthic d18O records, Paleoceanography, v. 20, PA1003, doi:10.1029/2004PA001071.
  3. ^ Bartoli, G. et al., 2005, Final closure of Panama and the onset of northern hemisphere glaciation, Earth Planet. Sci. Lett., v. 237, 3344.
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.