Neogene

Last updated
Neogene
23.03 ± 0.3 – 2.588 ± 0.04 Ma
15 Ma paleoglobe.png
A map of the world as it appeared during the Miocene Epoch, c. 15 Ma
Chronology
Etymology
Name formalityFormal
Usage information
Celestial body Earth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unit Period
Stratigraphic unit System
Time span formalityFormal
Lower boundary definition
Lower boundary GSSPLemme-Carrosio Section, Carrosio, Italy
44°39′32″N8°50′11″E / 44.6589°N 8.8364°E / 44.6589; 8.8364
Lower GSSP ratified1996 [4]
Upper boundary definition
Upper boundary GSSPMonte San Nicola Section, Gela, Sicily, Italy
37°08′49″N14°12′13″E / 37.1469°N 14.2035°E / 37.1469; 14.2035
Upper GSSP ratified2009 (as base of Quaternary and Pleistocene) [5]
Atmospheric and climatic data
Mean atmospheric O2 contentc. 21.5 vol %
(108 % of modern)
Mean atmospheric CO2 contentc. 280 ppm
(1 times pre-industrial)
Mean surface temperaturec. 14 °C
(0 °C above modern)

The Neogene ( /ˈniː.ədʒiːn/ NEE-ə-jeen, [6] [7] informally Upper Tertiary or Late Tertiary) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period 23.03 million years ago (Mya) to the beginning of the present Quaternary Period 2.58 Mya. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene. Some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. [8] The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes (1815–1868). [9]

Contents

During this period, mammals and birds continued to evolve into modern forms, while other groups of life remained relatively unchanged. The first humans ( Homo habilis ) appeared in Africa near the end of the period. [10] Some continental movements took place, the most significant event being the connection of North and South America at the Isthmus of Panama, late in the Pliocene. This cut off the warm ocean currents from the Pacific to the Atlantic Ocean, leaving only the Gulf Stream to transfer heat to the Arctic Ocean. The global climate cooled considerably throughout the Neogene, culminating in a series of continental glaciations in the Quaternary Period that follows.

Divisions

In ICS terminology, from upper (later, more recent) to lower (earlier):

The Pliocene Epoch is subdivided into two ages:

The Miocene Epoch is subdivided into six ages:

In different geophysical regions of the world, other regional names are also used for the same or overlapping ages and other timeline subdivisions.

The terms Neogene System (formal) and Upper Tertiary System (informal) describe the rocks deposited during the Neogene Period.

Geography

The continents in the Neogene were very close to their current positions. The Isthmus of Panama formed, connecting North and South America. The Indian subcontinent continued to collide with Asia, forming the Himalayas. Sea levels fell, creating land bridges between Africa and Eurasia and between Eurasia and North America.

Climate

The global climate became more seasonal and continued an overall drying and cooling trend which began during the Paleogene. The Early Miocene was relatively cool; [11] Early Miocene mid-latitude seawater and continental thermal gradients were already very similar to those of the present. [12] During the Middle Miocene, Earth entered a warm phase known as the Middle Miocene Climatic Optimum (MMCO), [11] which was driven by the emplacement of the Columbia River Basalt Group. [13] Around 11 Ma, the Middle Miocene Warm Interval gave way to the much cooler Late Miocene. [11] The ice caps on both poles began to grow and thicken, a process enhanced by positive feedbacks from increased formation of sea ice. [14] Between 7 and 5.3 Ma, a decrease in global temperatures termed the Late Miocene Cooling (LMC) ensued, driven by decreases in carbon dioxide concentrations. [15] During the Middle Pliocene, another warm interval occurred, interrupting the longer-term cooling trend. [11] By the end of the period the first of a series of glaciations of the current Ice Age began. [16]

Flora and fauna

Marine and continental flora and fauna have a modern appearance. The reptile group Choristodera went extinct in the early part of the period, while the amphibians known as Allocaudata disappeared at the end of it. Neogene also marked the end of the reptilian genera Langstonia and Barinasuchus, terrestrial predators that were the last surviving members of Sebecosuchia, a group related to crocodiles. The oceans were dominated by large carnivores like megalodons and livyatans, and 19 million years ago about 70% of all pelagic shark species disappeared. [17] Mammals and birds continued to be the dominant terrestrial vertebrates, and took many forms as they adapted to various habitats. The first hominins, the ancestors of humans may have appeared in southern Europe and migrated into Africa. [18] [19] The first humans (belonging to the species Homo habilis ) appeared in Africa near the end of the period. [10]

About 20 million years ago gymnosperms in the form of some conifer and cycad groups started to diversify and produce more species due to the changing conditions. [20] In response to the cooler, seasonal climate, tropical plant species gave way to deciduous ones and grasslands replaced many forests. Grasses therefore greatly diversified, and herbivorous mammals evolved alongside it, creating the many grazing animals of today such as horses, antelope, and bison. Ice age mammals like the mammoths and woolly rhinoceros were common in Pliocene. With lower levels of CO2 in the atmosphere, C4 plants expanded and reached ecological dominance in grasslands during the last 10 million years. Also Asteraceae (daisies) went through a significant adaptive radiation. [21] Eucalyptus fossil leaves occur in the Miocene of New Zealand, where the genus is not native today, but have been introduced from Australia. [22]

Disagreements

The Neogene traditionally ended at the end of the Pliocene Epoch, just before the older definition of the beginning of the Quaternary Period; many time scales show this division.

However, there was a movement amongst geologists (particularly marine geologists) to also include ongoing geological time (Quaternary) in the Neogene, while others (particularly terrestrial geologists) insist the Quaternary to be a separate period of distinctly different record. The somewhat confusing terminology and disagreement amongst geologists on where to draw what hierarchical boundaries is due to the comparatively fine divisibility of time units as time approaches the present, and due to geological preservation that causes the youngest sedimentary geological record to be preserved over a much larger area and to reflect many more environments than the older geological record. [8] By dividing the Cenozoic Era into three (arguably two) periods (Paleogene, Neogene, Quaternary) instead of seven epochs, the periods are more closely comparable to the duration of periods in the Mesozoic and Paleozoic Eras.

The International Commission on Stratigraphy (ICS) once proposed that the Quaternary be considered a sub-era (sub-erathem) of the Neogene, with a beginning date of 2.58 Ma, namely the start of the Gelasian Stage. In the 2004 proposal of the ICS, the Neogene would have consisted of the Miocene and Pliocene Epochs. [23] The International Union for Quaternary Research (INQUA) counterproposed that the Neogene and the Pliocene end at 2.58 Ma, that the Gelasian be transferred to the Pleistocene, and the Quaternary be recognized as the third period in the Cenozoic, citing key changes in Earth's climate, oceans, and biota that occurred 2.58 Ma and its correspondence to the Gauss-Matuyama magnetostratigraphic boundary. [24] [25] In 2006 ICS and INQUA reached a compromise that made Quaternary a sub-era, subdividing Cenozoic into the old classical Tertiary and Quaternary, a compromise that was rejected by International Union of Geological Sciences because it split both Neogene and Pliocene in two. [26]

Following formal discussions at the 2008 International Geological Congress in Oslo, Norway, [27] the ICS decided in May 2009 to make the Quaternary the youngest period of the Cenozoic Era with its base at 2.58 Mya and including the Gelasian Age, which was formerly considered part of the Neogene Period and Pliocene Epoch. [28] Thus the Neogene Period ends bounding the succeeding Quaternary Period at 2.58 Mya.

Related Research Articles

<span class="mw-page-title-main">Cenozoic</span> Third era of the Phanerozoic Eon (66 million years ago to present)

The Cenozoic is Earth's current geological era, representing the last 66 million years of Earth's history. It is characterised by the dominance of mammals, birds, conifers and flowering plants, a cooling and drying climate, and the current configuration of continents. It is the latest of three geological eras since complex life evolved, preceded by the Mesozoic and Paleozoic. It started with the Cretaceous–Paleogene extinction event, when many species, including the non-avian dinosaurs, became extinct in an event attributed by most experts to the impact of a large asteroid or other celestial body, the Chicxulub impactor.

The Miocene is the first geological epoch of the Neogene Period and extends from about 23.03 to 5.333 million years ago (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words μείων and καινός and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene.

The Pliocene is the epoch in the geologic time scale that extends from 5.333 million to 2.58 million years ago. It is the second and most recent epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch. Prior to the 2009 revision of the geologic time scale, which placed the four most recent major glaciations entirely within the Pleistocene, the Pliocene also included the Gelasian Stage, which lasted from 2.588 to 1.806 million years ago, and is now included in the Pleistocene.

<span class="mw-page-title-main">Pleistocene</span> First epoch of the Quaternary Period

The Pleistocene is the geological epoch that lasted from c. 2.58 million to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek πλεῖστος (pleîstos), meaning "most", and καινός, meaning "new".

<span class="mw-page-title-main">Phanerozoic</span> Fourth and current eon of the geological timescale

The Phanerozoic is the current and the latest of the four geologic eons in the Earth's geologic time scale, covering the time period from 538.8 million years ago to the present. It is the eon during which abundant animal and plant life has proliferated, diversified and colonized various niches on the Earth's surface, beginning with the Cambrian period when animals first developed hard shells that can be clearly preserved in the fossil record. The time before the Phanerozoic, collectively called the Precambrian, is now divided into the Hadean, Archaean and Proterozoic eons.

<span class="mw-page-title-main">Quaternary</span> Third and current period of the Cenozoic Era, from 2.58 million years ago to the present

The Quaternary 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). It follows the Neogene Period and spans from 2.58 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene and the Holocene although a third epoch, the Anthropocene, has been proposed but is not officially recognised by the ICS.

Tertiary is an obsolete term for the geologic period from 66 million to 2.6 million years ago. The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start of the Cenozoic Era, and extended to the beginning of the Quaternary glaciation at the end of the Pliocene Epoch. The time span covered by the Tertiary has no exact equivalent in the current geologic time system, but it is essentially the merged Paleogene and Neogene periods, which are informally called the Early Tertiary and the Late Tertiary, respectively.

The International Commission on Stratigraphy (ICS), sometimes unofficially referred to as the "International Stratigraphic Commission", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigraphical, geological, and geochronological matters on a global scale.

<span class="mw-page-title-main">Timeline of glaciation</span> Chronology of the major ice ages of the Earth

There have been five or six major ice ages in the history of Earth over the past 3 billion years. The Late Cenozoic Ice Age began 34 million years ago, its latest phase being the Quaternary glaciation, in progress since 2.58 million years ago.

The Yarmouthian stage and the Yarmouth Interglacial were part of a now obsolete geologic timescale of the early Quaternary of North America.

<span class="mw-page-title-main">Zanclean</span> Earliest age on the geologic time scale of the Pliocene era

The Zanclean is the lowest stage or earliest age on the geologic time scale of the Pliocene. It spans the time between 5.332 ± 0.005 Ma and 3.6 ± 0.005 Ma. It is preceded by the Messinian Age of the Miocene Epoch, and followed by the Piacenzian Age.

The Gelasian is an age in the international geologic timescale or a stage in chronostratigraphy, being the earliest or lowest subdivision of the Quaternary Period/System and Pleistocene Epoch/Series. It spans the time between 2.58 Ma and 1.80 Ma. It follows the Piacenzian Stage and is followed by the Calabrian Stage.

The Piacenzian is in the international geologic time scale the upper stage or latest age of the Pliocene. It spans the time between 3.6 ± 0.005 Ma and 2.588 ± 0.005 Ma. The Piacenzian is after the Zanclean and is followed by the Gelasian.

Calabrian is a subdivision of the Pleistocene Epoch of the geologic time scale, defined as 1.8 Ma—774,000 years ago ± 5,000 years, a period of ~1.026 million years.

The Serravallian is, in the geologic timescale, an age or a stage in the middle Miocene Epoch/Series, which spans the time between 13.82 Ma and 11.63 Ma. The Serravallian follows the Langhian and is followed by the Tortonian.

The Blancan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 4,750,000 to 1,806,000 years BP, a period of 2.944 million years. It is usually considered to start in the early-mid Pliocene Epoch and end by the early Pleistocene. The Blancan is preceded by the Hemphillian and followed by the Irvingtonian NALMA stages.

The Pre-Illinoian Stage is used by Quaternary geologists for the early and middle Pleistocene glacial and interglacial periods of geologic time in North America from ~2.5–0.2 Ma.

The European Land Mammal Mega Zones are zones in rock layers that have a specific assemblage of fossils (biozones) based on occurrences of fossil assemblages of European land mammals. These biozones cover most of the Cenozoic, with particular focus having been paid to the Neogene and Paleogene systems, the Quaternary has several competing systems. In cases when fossils of mammals are abundant, stratigraphers and paleontologists can use these biozones as a more practical regional alternative to the stages of the official ICS geologic timescale. European Land Mammal Mega Zones are often also confusingly referred to as ages, stages, or intervals.

<span class="mw-page-title-main">Early Pleistocene</span> Unofficial Pleistocene sub-epoch

The Early Pleistocene is an unofficial sub-epoch in the international geologic timescale in chronostratigraphy, being 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 and 0.773 ± 0.005 Ma. The term Early Pleistocene applies to both the Gelasian Age and the Calabrian Age.

<span class="mw-page-title-main">Late Cenozoic Ice Age</span> Ice age of the last 34 million years, in particular in Antarctica

The Late Cenozoic Ice Age, or Antarctic Glaciation, began 33.9 million years ago at the Eocene-Oligocene Boundary and is ongoing. It is Earth's current ice age or icehouse period. Its beginning is marked by the formation of the Antarctic ice sheets.

References

  1. ↑ Krijgsman, W.; Garcés, M.; Langereis, C. G.; Daams, R.; Van Dam, J.; Van Der Meulen, A. J.; Agustí, J.; Cabrera, L. (1996). "A new chronology for the middle to late Miocene continental record in Spain". Earth and Planetary Science Letters. 142 (3–4): 367–380. Bibcode:1996E&PSL.142..367K. doi:10.1016/0012-821X(96)00109-4.
  2. ↑ Retallack, G. J. (1997). "Neogene Expansion of the North American Prairie". PALAIOS. 12 (4): 380–390. doi:10.2307/3515337. JSTOR   3515337 . Retrieved 2008-02-11.
  3. ↑ "ICS Timescale Chart" (PDF). www.stratigraphy.org.
  4. ↑ Steininger, Fritz F.; M. P. Aubry; W. A. Berggren; M. Biolzi; A. M. Borsetti; Julie E. Cartlidge; F. Cati; R. Corfield; R. Gelati; S. Iaccarino; C. Napoleone; F. Ottner; F. Rögl; R. Roetzel; S. Spezzaferri; F. Tateo; G. Villa; D. Zevenboom (1997). "The Global Stratotype Section and Point (GSSP) for the base of the Neogene" (PDF). Episodes. 20 (1): 23–28. doi: 10.18814/epiiugs/1997/v20i1/005 .
  5. ↑ Gibbard, Philip; Head, Martin (September 2010). "The newly-ratified definition of the Quaternary System/Period and redefinition of the Pleistocene Series/Epoch, and comparison of proposals advanced prior to formal ratification" (PDF). Episodes. 33 (3): 152–158. doi:10.18814/epiiugs/2010/v33i3/002 . Retrieved 8 December 2020.
  6. ↑ "Neogene". Merriam-Webster Dictionary .
  7. ↑ "Neogene". Dictionary.com Unabridged (Online). n.d.
  8. 1 2 Tucker, M.E. (2001). Sedimentary petrology : an introduction to the origin of sedimentary rocks (3rd ed.). Osney Nead, Oxford, UK: Blackwell Science. ISBN   978-0-632-05735-1.
  9. ↑ Hörnes, M. (1853). "Mittheilungen an Professor Bronn gerichtet" [Reports addressed to Professor Bronn]. Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefaktenkunde (in German): 806–810. hdl:2027/hvd.32044106271273. From p. 806: "Das häufige Vorkommen der Wiener Mollusken … im trennenden Gegensatze zu den eocänen zusammenzufassen." (The frequent occurrence of Viennese mollusks in typical Miocene as well as in typical Pliocene deposits motivated me – in order to avoid the perpetual monotony [of providing] details about the deposits – to subsume both deposits provisionally under the name "Neogene" (νεος new and γιγνομαι to arise) in distinguishing contrast to the Eocene.)
  10. 1 2 Spoor, Fred; Gunz, Philipp; Neubauer, Simon; Stelzer, Stefanie; Scott, Nadia; Kwekason, Amandus; Dean, M. Christopher (March 2015). "Reconstructed Homo habilis type OH 7 suggests deep-rooted species diversity in early Homo". Nature. 519 (7541): 83–86. Bibcode:2015Natur.519...83S. doi:10.1038/nature14224. PMID   25739632. S2CID   4470282.
  11. 1 2 3 4 Scotese, Christopher R.; Song, Haijun; Mills, Benjamin J.W.; van der Meer, Douwe G. (April 2021). "Phanerozoic paleotemperatures: The earth's changing climate during the last 540 million years". Earth-Science Reviews . 215: 103503. Bibcode:2021ESRv..21503503S. doi:10.1016/j.earscirev.2021.103503. ISSN   0012-8252. S2CID   233579194. Archived from the original on 8 January 2021. Retrieved 17 July 2023. Alt URL
  12. ↑ Goedert, Jean; Amiot, Romain; Arnaut-Godet, Florent; Cuny, Gilles; Fourel, François; Hernandez, Jean-Alexis; Pedreira-Segade, Ulysse; Lécuyer, Christophe (1 September 2017). "Miocene (Burdigalian) seawater and air temperatures estimated from the geochemistry of fossil remains from the Aquitaine Basin, France". Palaeogeography, Palaeoclimatology, Palaeoecology . 481: 14–28. Bibcode:2017PPP...481...14G. doi:10.1016/j.palaeo.2017.04.024 . Retrieved 30 November 2022.
  13. ↑ Kasbohm, Jennifer; Schoene, Blair (19 September 2018). "Rapid eruption of the Columbia River flood basalt and correlation with the mid-Miocene climate optimum". Science Advances . 4 (9): 1–8. doi:10.1126/sciadv.aat8223. PMC   6154988 . Retrieved 19 July 2023.
  14. ↑ DeConto, Robert; Pollard, David; Harwood, David (24 August 2007). "Sea ice feedback and Cenozoic evolution of Antarctic climate and ice sheets". Paleoceanography and Paleoclimatology . 22 (3): 1–18. doi:10.1029/2006PA001350 . Retrieved 9 May 2023.
  15. ↑ Tanner, Thomas; Hernández-Almeida, Iván; Drury, Anna Joy; Guitián, José; Stoll, Heather (10 December 2020). "Decreasing Atmospheric CO2 During the Late Miocene Cooling". Paleoceanography and Paleoclimatology . 35 (12). doi:10.1029/2020PA003925. S2CID   230534117 . Retrieved 17 March 2023.
  16. ↑ Benn, Douglas I. (2010). Glaciers & glaciation (2nd ed.). London: Hodder Education. pp. 15–21. ISBN   9780340905791.
  17. ↑ Almost 20 Million Years Ago, Sharks Nearly Went Extinct
  18. ↑ "Scientists find 7.2-million-year-old pre-human remains in the Balkans". Phys.org. Retrieved 17 December 2017.
  19. ↑ "9.7 million-year-old teeth found in Germany resemble those of human ancestors in Africa". ResearchGate. Retrieved 17 December 2017.
  20. ↑ DNA duplication linked to the origin and evolution of pine trees and their relatives
  21. ↑ Palazzesi, Luis; Hidalgo, Oriane; Barreda, Viviana D.; Forest, Félix; Höhna, Sebastian (2022). "The rise of grasslands is linked to atmospheric CO2 decline in the late Palaeogene". Nature Communications. 13 (1): 293. Bibcode:2022NatCo..13..293P. doi:10.1038/s41467-021-27897-y. PMC   8755714 . PMID   35022396.
  22. ↑ "Eucalyptus fossils in New Zealand – the thin end of the wedge – Mike Pole". 22 September 2014.
  23. ↑ Lourens, L., Hilgen, F., Shackleton, N.J., Laskar, J., Wilson, D., (2004) "The Neogene Period". In: Gradstein, F., Ogg, J., Smith, A.G. (Eds.), Geologic Time Scale, Cambridge University Press, Cambridge.
  24. ↑ Clague, John et al. (2006) "Open Letter by INQUA Executive Committee" Archived 2006-09-23 at the Wayback Machine Quaternary Perspective, the INQUA Newsletter International Union for Quaternary Research 16(1)
  25. ↑ Clague, John; et al. (2006). "Open Letter by INQUA Executive Committee" (PDF). Quaternary Perspective, the INQUA Newsletter. International Union for Quaternary Research. 16 (1): 158–159. doi:10.1016/j.quaint.2006.06.001. ISSN   1040-6182. Archived from the original (PDF) on 2006-09-23. Retrieved 2006-09-23.
  26. ↑ "ICS: Consolidated Annual Report for 2006" (PDF). Stratigraphy.org. Retrieved 15 June 2007.
  27. ↑ "Geoparks and Geotourism – Field Excursion of South America". 33igc.org. Retrieved 17 December 2017.
  28. ↑ "See the 2009 version of the ICS geologic time scale". Quaternary.stratigraphy.org.uk. Retrieved 17 December 2017.
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