Quaternary Period
2.58–0 million years ago
Mean atmospheric 2 content over period durationc. 20.8 vol %[1][2]
(104 % of modern level)
Mean atmospheric 2 content over period durationc. 250 ppm[3]
(1 times pre-industrial level)
Mean surface temperature over period durationc. 14 °C[4]
(0 °C above modern level)

Quaternary ( i/) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS).[5] It follows the Neogene Period and spans from 2.588 ± 0.005 million years ago to the present.[5] The Quaternary Period is divided into two epochs: the Pleistocene (2.588 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today).[5] The informal term "Late Quaternary" refers to the past 0.5–1.0 million years.[6]

The Quaternary Period is typically defined by the cyclic growth and decay of continental ice sheets associated with Milankovitch cycles and the associated climate and environmental changes that occurred.[7][8]

Research history

In 1759 Giovanni Arduino proposed that the geological strata of northern Italy could be divided into four successive formations or "orders" (Italian: quattro ordini).[9] The term "quaternary" was introduced by Jules Desnoyers in 1829 for sediments of France's Seine Basin that seemed clearly to be younger than Tertiary Period rocks.[10][11][12]

The Quaternary Period follows the Neogene Period and extends to the present. The Quaternary covers the time span of glaciations classified as the Pleistocene, and includes the present interglacial time-period, the Holocene.

This places the start of the Quaternary at the onset of Northern Hemisphere glaciation approximately 2.6 million years ago. Prior to 2009, the Pleistocene was defined to be from 1.805 million years ago to the present, so the current definition of the Pleistocene includes a portion of what was, prior to 2009, defined as the Pliocene.

Subdivisions of the Quaternary System
Age (Ma)
Quaternary Holocene Meghalayan 0 0.0042
Northgrippian 0.0042 0.0082
Greenlandian 0.0082 0.0117
Pleistocene 'Tarantian' 0.0117 0.126
'Chibanian' 0.126 0.781
Calabrian 0.781 1.80
Gelasian 1.80 2.58
Neogene Pliocene Piacenzian 2.58 3.60
Notes and references[13][14][15]
Subdivision of the Quaternary period according to the ICS, as of 2018.[13]

For the Holocene, dates are relative to the year 2000 (e.g. Greenlandian began 11,700 years before 2000). For the begin of the Northgrippian a date of 8,236 years before 2000 has been set.[14] The Meghalayan has been set to begin 4,250 years before 2000, apparently from a calibrated radio-carbon date of 4,200 years BP i.e. before 1950.[15][clarification needed]

'Chibanian' and 'Tarantian' are informal, unofficial names proposed to replace the also informal, unofficial 'Middle Pleistocene' and 'Upper Pleistocene' subseries/subepochs respectively.

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.

Quaternary stratigraphers usually worked with regional subdivisions. From the 1970s, the International Commission on Stratigraphy (ICS) tried to make a single geologic time scale based on GSSP's, which could be used internationally. The Quaternary subdivisions were defined based on biostratigraphy instead of paleoclimate.

This led to the problem that the proposed base of the Pleistocene was at 1.805 Mya, long after the start of the major glaciations of the northern hemisphere. The ICS then proposed to abolish use of the name Quaternary altogether, which appeared unacceptable to the International Union for Quaternary Research (INQUA).

In 2009, it was decided to make the Quaternary the youngest period of the Cenozoic Era with its base at 2.588 Mya and including the Gelasian stage, which was formerly considered part of the Neogene Period and Pliocene Epoch.[16]

The Anthropocene has been proposed as a third epoch as a mark of the anthropogenic impact on the global environment starting with the Industrial Revolution, or about 200 years ago.[17] The Anthropocene is not officially designated by the ICS, however, but a working group is currently aiming to complete a proposal for the creation of an epoch or sub-period by 2016.[18]

Other Languages
Afrikaans: Kwartêr
Alemannisch: Quartär (Geologie)
asturianu: Edá Cuaternaria
azərbaycanca: Dördüncü dövr
Bân-lâm-gú: Tē-sì-kí
Basa Banyumasan: Quater
башҡортса: Дүртенсел осор
български: Кватернер
català: Quaternari
čeština: Čtvrtohory
Cymraeg: Cwaternaidd
dansk: Kvartær
eesti: Kvaternaar
Esperanto: Kvaternaro
euskara: Kuaternario
فارسی: کواترنری
français: Quaternaire
Gaeilge: Ceathartha
한국어: 제4기
hrvatski: Kvartar
Bahasa Indonesia: Kuarter
italiano: Quaternario
עברית: רביעון
Latina: Quaternarium
latviešu: Kvartārs
lietuvių: Kvarteras
Nederlands: Kwartair
日本語: 第四紀
Nordfriisk: Quartär
norsk: Kvartær
norsk nynorsk: Kvartær
occitan: Quaternari
oʻzbekcha/ўзбекча: Toʻrtlamchi sistema
پنجابی: کواٹرنری
Piemontèis: Era quaternaria
Plattdüütsch: Quartär (Geologie)
polski: Czwartorzęd
português: Quaternário
română: Cuaternar
саха тыла: Төрдүс
shqip: Kuaternari
Simple English: Quaternary
slovenčina: Kvartér
slovenščina: Kvartar
српски / srpski: Квартар
srpskohrvatski / српскохрватски: Kvartar
svenska: Kvartär
Tagalog: Kwaternaryo
тоҷикӣ: Антропоген
Türkçe: Kuaterner
Tiếng Việt: Kỷ Đệ Tứ
粵語: 第四紀
中文: 第四紀