Subdivisions of the Quaternary Period
Quaternary Holocene Meghalayan 0 4,200
Northgrippian 4,200 8,200
Greenlandian 8,200 11,700
Pleistocene 'Upper' 11,700 129ka
Chibanian 129ka 774ka
Calabrian 774ka 1.80Ma
Gelasian 1.80Ma 2.58Ma
Neogene Pliocene Piacenzian 2.58Ma 3.60Ma
Notes and references[1][2]
Subdivision of the Quaternary Period according to the ICS, as of January 2020.[1]

For the Holocene, dates are relative to the year 2000 (e.g. Greenlandian began 11,700 years before 2000). For the beginning of the Northgrippian a date of 8,236 years before 2000 has been set.[2] The Meghalayan has been set to begin 4,250 years before 2000.[1]

'Tarantian' is an informal, unofficial name proposed for a stage/age to replace the equally informal, unofficial 'Upper Pleistocene' subseries/subepoch.

In Europe and North America, the Holocene is subdivided into Preboreal, Boreal, Atlantic, Subboreal, and Subatlantic stages of the Blytt–Sernander time scale. There are many regional subdivisions for the Upper or Late Pleistocene; usually these represent locally recognized cold (glacial) and warm (interglacial) periods. The last glacial period ends with the cold Younger Dryas substage.

The Early Pleistocene is an unofficial sub-epoch in the international geologic timescale in chronostratigraphy, representing the earliest division of the Pleistocene Epoch within the ongoing Quaternary Period. It is currently estimated to span the time between 2.580 ± 0.005 Ma (million years ago) and 0.773 ± 0.005 Ma. The term Early Pleistocene applies to both the Gelasian Age and the Calabrian Age.[1]

While the Gelasian and the Calabrian have officially been defined by the International Union of Geological Sciences (IUGS) to effectively constitute the Early Pleistocene, the succeeding Chibanian and Tarantian ages have yet to be ratified.[3] These proposed ages are unofficially termed the Middle Pleistocene and Late Pleistocene respectively. The Chibanian provisionally spans time from 773 ka to 126 ka, and the Tarantian from then until the definitive end of the whole Pleistocene, c. 9700 BC in the 10th millennium BC.[1]

Notes edit

  1. ^ a b c d e Cohen, K. M.; Finney, S. C.; Gibbard, P. L.; Fan, J.-X. (January 2020). "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy. Retrieved 23 February 2020.
  2. ^ a b Mike Walker; et al. (December 2018). "Formal ratification of the subdivision of the Holocene Series/Epoch (Quaternary System/Period)" (PDF). Episodes. 41 (4). Subcommission on Quaternary Stratigraphy (SQS): 213–223. doi:10.18814/epiiugs/2018/018016. Retrieved 11 November 2019. This proposal on behalf of the SQS has been approved by the International Commission on Stratigraphy (ICS) and formally ratified by the Executive Committee of the International Union of Geological Sciences (IUGS).
  3. ^ P. L. Gibbard (17 April 2015). "The Quaternary System/Period and its major sub-divisions". Russian Geology and Geophysics. Special Issue: Topical Problems of Stratigraphy and Evolution of the Biosphere. 56 (4). Elsevier BV: 686–688. Bibcode:2015RuGG...56..686G. doi:10.1016/j.rgg.2015.03.015. Retrieved 13 November 2019.