Sunday, March 15, 2009

Bringing order to the Neogene

The International Stratigraphic Commission has started an interesting discussion on the future of the Neogene and Quarternary on it's new bulletin board. Two position papers on the definition of the boundaries of the Quaternary, Pleistocene, Neogene and Pliocene are presented there.
These proposals have been submitted by the ICS Quaternary Subcommission (QS) and the ICS Neogene Subcommission(NS) and they heavily differ ... here is a short summary of the two positions:

  • QS proposes a Quarternary System succeeding the Neogene but the NS wish a Quarternary Subsystem of Neogene which extends to present
  • Both agree that the base of the Quarternary will be lowered from 1.8 to 2.6 Mio years
  • QS proposes to lower the bottom of the Pleistocene to the GSSP of the Gelasian Stage wheras the NS proposes the subdivision of the Pliocene in a Upper and Lower Pliocene where the upper Pliocene=Quarternary
  • The NS regards the Geliasian as part of the Pliocene while the QS includes the Geliasian to the Pleistocene.
The complete position papers can be viewed at stratigraphy.org.

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