Chibanian


The Chibanian, widely known by its previous designation of Middle Pleistocene is an age in the international geologic timescale or a stage in chronostratigraphy, being the second division of the Pleistocene Epoch within the ongoing Quaternary Period. The Chibanian name was officially ratified in January 2020. It is currently estimated to span the time between 0.770 Ma and 0.126 Ma, also expressed as 770–126 ka. It includes the transition in palaeoanthropology from the Lower to the Middle Palaeolithic over 300 ka.
The Chibanian is preceded by the Calabrian and succeeded by the proposed Tarantian. The beginning of the Chibanian is the Brunhes–Matuyama reversal, when the Earth's magnetic field last underwent reversal. It ends with the onset of the Eemian interglacial period.
The term Middle Pleistocene was in use as a provisional or "quasi-formal" designation by the International Union of Geological Sciences. While the three lowest ages of the Pleistocene, the Gelasian, Calabrian and Chibanian have been officially defined, the Late Pleistocene has yet to be formally defined, along with consideration of a proposed Anthropocene sub-division of the Holocene.

Definition process

The International Union of Geological Sciences had previously proposed replacement of the Middle Pleistocene by an Ionian Age based on strata found in Italy. In November 2017, however, the Chibanian replaced the Ionian as the Subcommission on Quaternary Stratigraphy's preferred GSSP proposal for the age that should replace the Middle Pleistocene sub-epoch. The "Chibanian" name was ratified by the IUGS in January 2020.

Palaeoanthropology

The Chibanian includes the transition in palaeoanthropology from the Lower to the Middle Palaeolithic: i.e., the emergence of Homo sapiens sapiens between 300 ka and 400 ka. The oldest known human DNA dates to the Middle Pleistocene, around 430,000 years ago. This is the oldest found, as of 2016.

Chronology

Agepaleoclimateglaciationpalaeoanthropology
790–761 kaMIS 19Günz glaciationPeking Man
761–712 kaMIS 18--
712–676 kaMIS 17--
676–621 kaMIS 16--
621–563 kaMIS 15Gunz-Haslach interglacialHeidelberg Man, Bodo cranium
563–524 kaMIS 14--
524–474 kaMIS 13end of Cromerian interglacialBoxgrove Man
474–424 kaMIS 12Anglian Stage in Britain; Haslach glaciationTautavel Man
424–374 kaMIS 11Hoxnian, Yarmouthian Swanscombe Man
374–337 kaMIS 10Mindel glaciation, Elster glaciation, Riss glaciation-
337–300 kaMIS 9Purfleet Interglacial in BritainMousterian
300–243 kaMIS 8Irhoud 1 ; Middle Paleolithic; Haplogroup A
243–191 kaMIS 7Aveley Interglacial in BritainGalilee Man; Haua Fteah
191–130 kaMIS 6Illinoian StageHerto Man ; Macro-haplogroup L ; Mousterian
130-123 kaMIS 5epeak of Eemian interglacial sub-stage, or Ipswichian in BritainKlasies River Caves; Sangoan