Pliocene

Last updated
Pliocene
5.333 – 2.58 Ma
O
S
D
C
P
T
J
K
Pg
N
Chronology
Etymology
Name formalityFormal
Usage information
Celestial body Earth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unit Epoch
Stratigraphic unit Series
Time span formalityFormal
Lower boundary definitionBase of the Thvera magnetic event (C3n.4n), which is only 96 ka (5 precession cycles) younger than the GSSP
Lower boundary GSSPHeraclea Minoa section, Heraclea Minoa, Cattolica Eraclea, Sicily, Italy
37°23′30″N13°16′50″E / 37.3917°N 13.2806°E / 37.3917; 13.2806
GSSP ratified2000 [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
GSSP ratified2009 (as base of Quaternary and Pleistocene) [5]

The Pliocene ( /ˈpl.əˌsn,ˈpl.-/ PLY-ə-seen, PLY-oh-; [6] [7] also Pleiocene [8] ) Epoch is the epoch in the geologic timescale that extends from 5.333 million to 2.58 [9] million years BP. 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. [10]

Contents

As with other older geologic periods, the geological strata that define the start and end are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The boundaries defining the Pliocene are not set at an easily identified worldwide event but rather at regional boundaries between the warmer Miocene and the relatively cooler Pliocene. The upper boundary was set at the start of the Pleistocene glaciations.

Etymology

Charles Lyell (later Sir Charles) gave the Pliocene its name in Principles of Geology (volume 3, 1833). [11]

The word pliocene comes from the Greek words πλεῖον (pleion, "more") and καινός (kainos, "new" or "recent") [12] and means roughly "continuation of the recent", referring to the essentially modern marine mollusc fauna.

Subdivisions

Some schemes for subdivisions of the Pliocene Pliocene Chart.jpg
Some schemes for subdivisions of the Pliocene

In the official timescale of the ICS, the Pliocene is subdivided into two stages. From youngest to oldest they are:

The Piacenzian is sometimes referred to as the Late Pliocene, whereas the Zanclean is referred to as the Early Pliocene.

In the system of

In the Paratethys area (central Europe and parts of western Asia) the Pliocene contains the Dacian (roughly equal to the Zanclean) and Romanian (roughly equal to the Piacenzian and Gelasian together) stages. As usual in stratigraphy, there are many other regional and local subdivisions in use.

In Britain the Pliocene is divided into the following stages (old to young): Gedgravian, Waltonian, Pre-Ludhamian, Ludhamian, Thurnian, Bramertonian or Antian, Pre-Pastonian or Baventian, Pastonian and Beestonian. In the Netherlands the Pliocene is divided into these stages (old to young): Brunssumian C, Reuverian A, Reuverian B, Reuverian C, Praetiglian, Tiglian A, Tiglian B, Tiglian C1-4b, Tiglian C4c, Tiglian C5, Tiglian C6 and Eburonian. The exact correlations between these local stages and the International Commission on Stratigraphy (ICS) stages is still a matter of detail. [18]

Climate

Mid-Pliocene reconstructed annual sea surface temperature anomaly Pliocene sst anomaly.png
Mid-Pliocene reconstructed annual sea surface temperature anomaly

The global average temperature in the mid-Pliocene (3.3–3 mya) was 2–3 °C higher than today, [19] carbon dioxide levels were the same as today, [20] and global sea level was 25 m higher. [21] The northern hemisphere ice sheet was ephemeral before the onset of extensive glaciation over Greenland that occurred in the late Pliocene around 3 Ma. [22] The formation of an Arctic ice cap is signaled by an abrupt shift in oxygen isotope ratios and ice-rafted cobbles in the North Atlantic and North Pacific ocean beds. [23] Mid-latitude glaciation was probably underway before the end of the epoch. The global cooling that occurred during the Pliocene may have spurred on the disappearance of forests and the spread of grasslands and savannas. [24]

Paleogeography

Examples of migrant species in the Americas after the formation of the Isthmus of Panama. Olive green silhouettes denote North American species with South American ancestors; blue silhouettes denote South American species of North American origin. Great American Biotic Interchange examples.svg
Examples of migrant species in the Americas after the formation of the Isthmus of Panama. Olive green silhouettes denote North American species with South American ancestors; blue silhouettes denote South American species of North American origin.

Continents continued to drift, moving from positions possibly as far as 250 km from their present locations to positions only 70 km from their current locations. South America became linked to North America through the Isthmus of Panama during the Pliocene, making possible the Great American Interchange and bringing a nearly complete end to South America's distinctive large marsupial predator and native ungulate faunas. [25] The formation of the Isthmus had major consequences on global temperatures, since warm equatorial ocean currents were cut off and an Atlantic cooling cycle began, with cold Arctic and Antarctic waters dropping temperatures in the now-isolated Atlantic Ocean. [26]

Africa's collision with Europe formed the Mediterranean Sea, cutting off the remnants of the Tethys Ocean. The border between the Miocene and the Pliocene is also the time of the Messinian salinity crisis. [27] [28]

The land bridge between Alaska and Siberia (Beringia) was first flooded near the start of the Pliocene, allowing marine organisms to spread between the Arctic and Pacific Oceans. The bridge would continue to be periodically flooded and restored thereafter. [29]

Pliocene marine formations are exposed in northeast Spain, [30] southern California, [31] New Zealand, [32] and Italy. [33]

During the Pliocene parts of southern Norway and southern Sweden that had been near sea level rose. In Norway this rise elevated the Hardangervidda plateau to 1200 m in the Early Pliocene. [34] In Southern Sweden similar movements elevated the South Swedish highlands leading to a deflection of the ancient Eridanos river from its original path across south-central Sweden into a course south of Sweden. [35]

Flora

The change to a cooler, dry, seasonal climate had considerable impacts on Pliocene vegetation, reducing tropical species worldwide. Deciduous forests proliferated, coniferous forests and tundra covered much of the north, and grasslands spread on all continents (except Antarctica). Tropical forests were limited to a tight band around the equator, and in addition to dry savannahs, deserts appeared in Asia and Africa. [36] [ failed verification ]

Fauna

Both marine and continental faunas were essentially modern, although continental faunas were a bit more primitive than today. The first recognizable hominins, the australopithecines, appeared in the Pliocene.

The land mass collisions meant great migration and mixing of previously isolated species, such as in the Great American Interchange. Herbivores got bigger, as did specialized predators.

Mammals

19th century artist's impression of a Pliocene landscape Landscape of the Pliocene epoch - showing environment at the time of men's appearance - drawn by Riou.jpg
19th century artist's impression of a Pliocene landscape

In North America, rodents, large mastodons and gomphotheres, and opossums continued successfully, while hoofed animals (ungulates) declined, with camel, deer and horse all seeing populations recede. Rhinos, three-toed horses ( Nannippus ), oreodonts, protoceratids, and chalicotheres became extinct. Borophagine dogs and Agriotherium became extinct, but other carnivores including the weasel family diversified, and dogs and short-faced bears did well. Ground sloths, huge glyptodonts, and armadillos came north with the formation of the Isthmus of Panama.

In Eurasia rodents did well, while primate distribution declined. Elephants, gomphotheres and stegodonts were successful in Asia, and hyraxes migrated north from Africa. Horse diversity declined, while tapirs and rhinos did fairly well. Cows and antelopes were successful, and some camel species crossed into Asia from North America. Hyenas and early saber-toothed cats appeared, joining other predators including dogs, bears and weasels.

Human evolution during the Pliocene
Pliocene

Africa was dominated by hoofed animals, and primates continued their evolution, with australopithecines (some of the first hominins) appearing in the late Pliocene. Rodents were successful, and elephant populations increased. Cows and antelopes continued diversification and overtook pigs in numbers of species. Early giraffes appeared. Horses and modern rhinos came onto the scene. Bears, dogs and weasels (originally from North America) joined cats, hyenas and civets as the African predators, forcing hyenas to adapt as specialized scavengers.

South America was invaded by North American species for the first time since the Cretaceous, with North American rodents and primates mixing with southern forms. Litopterns and the notoungulates, South American natives, were mostly wiped out, except for the macrauchenids and toxodonts, which managed to survive. Small weasel-like carnivorous mustelids, coatis and short-faced bears migrated from the north. Grazing glyptodonts, browsing giant ground sloths and smaller caviomorph rodents, pampatheres, and armadillos did the opposite, migrating to the north and thriving there.

The marsupials remained the dominant Australian mammals, with herbivore forms including wombats and kangaroos, and the huge Diprotodon . Carnivorous marsupials continued hunting in the Pliocene, including dasyurids, the dog-like thylacine and cat-like Thylacoleo . The first rodents arrived in Australia. The modern platypus, a monotreme, appeared.

Birds

Titanis Titanis07DB.jpg
Titanis

The predatory South American phorusrhacids were rare in this time; among the last was Titanis , a large phorusrhacid that migrated to North America and rivaled mammals as top predator. Other birds probably evolved at this time, some modern (such as the genera Cygnus , Bubo , Struthio and Corvus ), some now extinct.

Reptiles and amphibians

Alligators and crocodiles died out in Europe as the climate cooled. Venomous snake genera continued to increase as more rodents and birds evolved. Rattlesnakes first appeared in the Pliocene. The modern species Alligator mississippiensis , having evolved in the Miocene, continued into the Pliocene, except with a more northern range; specimens have been found in very late Miocene deposits of Tennessee. Giant tortoises still thrived in North America, with genera like Hesperotestudo . Madtsoid snakes were still present in Australia. The amphibian order Allocaudata became extinct.

Oceans

Oceans continued to be relatively warm during the Pliocene, though they continued cooling. The Arctic ice cap formed, drying the climate and increasing cool shallow currents in the North Atlantic. Deep cold currents flowed from the Antarctic.

The formation of the Isthmus of Panama about 3.5 million years ago [37] cut off the final remnant of what was once essentially a circum-equatorial current that had existed since the Cretaceous and the early Cenozoic. This may have contributed to further cooling of the oceans worldwide.

The Pliocene seas were alive with sea cows, seals, sea lions and sharks.

Supernovae

In 2002, Narciso Benítez et al. calculated that roughly 2 million years ago, around the end of the Pliocene epoch, a group of bright O and B stars called the Scorpius-Centaurus OB association passed within 130 light-years of Earth and that one or more supernova explosions gave rise to a feature known as the Local Bubble. [38] Such a close explosion could have damaged the Earth's ozone layer and caused the extinction of some ocean life (at its peak, a supernova of this size could have the same absolute magnitude as an entire galaxy of 200 billion stars). [39] [40] Radioactive iron-60 isotopes that have been found in ancient seabed deposits further back this finding, as there are no natural sources for this radioactive isotope on Earth, but they can be produced in supernovae. [41] Furthermore, iron-60 residues point to a huge spike 2.6 million years ago, but an excess scattered over 10 million years can also be found, suggesting that there may have been multiple, relatively close supernovae. [42]

In 2019, researchers found more of these interstellar iron-60 isotopes in Antarctica, which have been associated with the Local Interstellar Cloud. [43]

See also

Related Research Articles

Cenozoic 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 characterized by the dominance of mammals, birds 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; its name comes from the Greek words μείων and καινός and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene is preceded by the Oligocene and is followed by the Pliocene.

The Neogene 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. The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes (1815–1868).

The Oligocene is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present. As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek ὀλίγος and καινός, and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period.

Pleistocene First epoch of the Quaternary Period

The Pleistocene is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the world's most recent period of repeated glaciations. Before a change 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 and καινός (kainós, "new".

Phanerozoic Fourth and current eon of the geological timescale

The Phanerozoic Eon is the current geologic eon in the geologic time scale, and the one during which abundant animal and plant life has existed. It covers 541 million years to the present, and it began with the Cambrian Period when animals first developed hard shells preserved in the fossil record. The time before the Phanerozoic, called the Precambrian, is now divided into the Hadean, Archaean and Proterozoic eons.

Quaternary Third and current period of the Cenozoic Era, 2.59 to 0 million years ago

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 2.588 ± 0.005 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene and the Holocene. The informal term "Late Quaternary" refers to the past 0.5–1.0 million years.

Tertiary is a widely used but 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 Lower Tertiary and the Upper Tertiary, respectively.

Pika Genus of mammals in the family Ochotonidae of the order Lagomorpha

A pika is a small, mountain-dwelling mammal found in Asia and North America. With short limbs, very round body, an even coat of fur, and no external tail, they resemble their close relative, the rabbit, but with short, rounded ears. The large-eared pika of the Himalayas and nearby mountains is found at heights of more than 6,000 m (20,000 ft), among the highest of any mammal.

Timeline of glaciation 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.

<i>Balaena</i> Genus of mammals

Balaena is a genus of cetacean (whale) in the family Balaenidae. Balaena is considered a monotypic genus, as it has only a single extant species, the bowhead whale. It was named in 1758 by Linnaeus, who at the time considered all of the right whales as a single species. Historically, both the family Balaenidae and genus Balaena were known by the common name, "right whales", however Balaena are now known as bowhead whales.

Zanclean

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 2.588 ± 0.005 Ma and 1.806 ± 0.005 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.

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.

Choctaw Sea

The Choctaw Sea was a Cenozoic eutropical subsea, which along with the Okeechobean Sea, occupied the eastern Gulf of Mexico basin system bounding Florida.

Okeechobean Sea

The Okeechobean Sea was a Cenozoic eutropical subsea, which along with the Choctaw Sea, occupied the eastern Gulf of Mexico basin system bounding Florida.

This article records new taxa of fossil mammals of every kind that have been described during the year 2010, as well as other significant discoveries and events related to paleontology of mammals that occurred in the year 2010.

Late Cenozoic Ice Age 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. The Late Cenozoic Ice Age gets its name due to the fact that it covers roughly the last half of Cenozoic era so far.

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. 1 2 Van Couvering, John; Castradori, Davide; Cita, Maria; Hilgen, Frederik; Rio, Domenico (September 2000). "The base of the Zanclean Stage and of the Pliocene Series" (PDF). Episodes. 23 (3): 179–187. doi: 10.18814/epiiugs/2000/v23i3/005 .
  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. "Pliocene". Merriam-Webster Dictionary .
  7. "Pliocene". Dictionary.com Unabridged. Random House.
  8. "Pleiocene". Dictionary.com Unabridged. Random House.
  9. See the 2014 version of the ICS geologic time scale Archived 2014-05-30 at the Wayback Machine
  10. Ogg, James George; Ogg, Gabi; Gradstein F. M. (2008). The Concise Geologic Time Scale. Cambridge University Press. pp. 150–1. ISBN   9780521898492.
  11. See:
  12. "Pliocene". Online Etymology Dictionary .
  13. Castradori, D.; Rio, D.; Hilgen, F. J.; Lourens, L. J. (1998). "The Global Standard Stratotype-section and Point (GSSP) of the Piacenzian Stage (Middle Pliocene)". Episodes. 21 (2): 88–93. doi: 10.18814/epiiugs/1998/v21i2/003 .
  14. Tedford, Richard H.; Albright, L. Barry; Barnosky, Anthony D.; Ferrusquia-Villafranca, Ismael; Hunt, Robert M.; Storer, John E.; Swisher, Carl C.; Voorhies, Michael R.; Webb, S. David; Whistler, David P. (2004-12-31). "6. Mammalian Biochronology of the Arikareean Through Hemphillian Interval (Late Oligocene Through Early Pliocene Epochs)". Late Cretaceous and Cenozoic Mammals of North America: 169–231. doi:10.7312/wood13040-008.
  15. Hulbert, Richard C., Jr. (2 August 2016). "Hemphillian North American Land Mammal Age". Fossil Species of Florida. Florida Museum. Retrieved 7 June 2021.
  16. Hulbert, Richard C., Jr. (2 August 2016). "Blancan North American Land Mammal Age". Fossil Species of Florida. Florida Museum. Retrieved 7 June 2021.
  17. Flynn, J., and C.C. Swisher. 1995. Cenozoic South American Land Mammal Ages: correlation to global geochronology. Geochronology Time Scales and Global Stratigraphic Correlation, SEPM Special Publication 54. 317–333.
  18. Kuhlmann, G.; C.G. Langereis; D. Munsterman; R.-J. van Leeuwen; R. Verreussel; J.E. Meulenkamp; Th.E. Wong (2006). "Integrated chronostratigraphy of the Pliocene-Pleistocene interval and its relation to the regional stratigraphical stages in the southern North Sea region" (PDF). Netherlands Journal of Geosciences. 85: 19–35. doi: 10.1017/S0016774600021405 . S2CID   62803118.
  19. Robinson, M.; Dowsett, H.J.; Chandler, M.A. (2008). "Pliocene role in assessing future climate impacts". Eos, Transactions, American Geophysical Union. 89 (49): 501–502. Bibcode:2008EOSTr..89..501R. doi:10.1029/2008eo490001.
  20. "Solutions: Responding to Climate Change". Climate.Nasa.gov. Retrieved 1 September 2016.
  21. Dwyer, G.S.; Chandler, M.A. (2009). "Mid-Pliocene sea level and continental ice volume based on coupled benthic Mg/Ca palaeotemperatures and oxygen isotopes". Phil. Trans. Royal Soc. A. 367 (1886): 157–168. Bibcode:2009RSPTA.367..157D. doi:10.1098/rsta.2008.0222. hdl: 10161/6586 . PMID   18854304. S2CID   3199617.
  22. Bartoli, G.; et al. (2005). "Final closure of Panama and the onset of northern hemisphere glaciation". Earth Planet. Sci. Lett. 237 (1–2): 3344. Bibcode:2005E&PSL.237...33B. doi: 10.1016/j.epsl.2005.06.020 .
  23. Van Andel (1994), p. 226.
  24. "The Pliocene epoch". University of California Museum of Paleontology. Retrieved 2008-03-25.
  25. Webb, S. David (1991). "Ecogeography and the Great American Interchange". Paleobiology. 17 (3): 266–280. doi:10.1017/S0094837300010605. JSTOR   2400869.
  26. Bartoli, G.; Sarnthein, M.; Weinelt, M.; Erlenkeuser, H.; Garbe-Schönberg, D.; Lea, D.W. (August 2005). "Final closure of Panama and the onset of northern hemisphere glaciation". Earth and Planetary Science Letters. 237 (1–2): 33–44. doi:10.1016/j.epsl.2005.06.020.
  27. Gautier, F., Clauzon, G., Suc, J.P., Cravatte, J., Violanti, D., 1994. Age and duration of the Messinian salinity crisis. C.R. Acad. Sci., Paris (IIA) 318, 1103–1109.
  28. Krijgsman, W (August 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.
  29. Gladenkov, Andrey Yu; Oleinik, Anton E; Marincovich, Louie; Barinov, Konstantin B (July 2002). "A refined age for the earliest opening of Bering Strait". Palaeogeography, Palaeoclimatology, Palaeoecology. 183 (3–4): 321–328. doi:10.1016/S0031-0182(02)00249-3.
  30. Gibert, Jordi Maria de; Martinell, Jordi (January 1995). "Sedimentary substrate andtrace fossil assemblages in marine Pliocene deposits in Northeast Spain". Geobios. 28: 197–206. doi:10.1016/S0016-6995(95)80166-9.
  31. Deméré, Thomas A. (1983). "The Neogene San Diego basin: a review of the marine Pliocene San Diego formation". Cenozoic Marine Sedimentation, Pacific Margin. Pacific Section,m Society for Sedimentary Geology. Retrieved 7 June 2021.
  32. Saul, G.; Naish, T.R.; Abbott, S.T.; Carter, R.M. (1 April 1999). "Sedimentary cyclicity in the marine Pliocene-Pleistocene of the Wanganui basin (New Zealand): Sequence stratigraphic motifs characteristic of the past 2.5 m.y.". GSA Bulletin. 111 (4): 524-537. doi:10.1130/0016-7606(1999)111<0524:SCITMP>2.3.CO;2.
  33. Selli, Raimondo (September 1965). "The Pliocene-Pleistocene boundary in Italian marine sections and its relationship to continental stratigraphies". Progress in Oceanography. 4: 67–86. doi:10.1016/0079-6611(65)90041-8.
  34. Japsen, Peter; Green, Paul F.; Chalmers, James A.; Bonow, Johan M. (17 May 2018). "Mountains of southernmost Norway: uplifted Miocene peneplains and re-exposed Mesozoic surfaces". Journal of the Geological Society. 175 (5): 721–741. Bibcode:2018JGSoc.175..721J. doi:10.1144/jgs2017-157. S2CID   134575021.
  35. Lidmar-Bergström, Karna; Olvmo, Mats; Bonow, Johan M. (2017). "The South Swedish Dome: a key structure for identification of peneplains and conclusions on Phanerozoic tectonics of an ancient shield". GFF . 139 (4): 244–259. doi:10.1080/11035897.2017.1364293. S2CID   134300755.
  36. Mares, Micheal A., ed. (1999). "Miocene". Encyclopedia of Deserts. University of Oaklahoma Press. ISBN   0-8061-3146-2.
  37. Keigwin, Lloyd D. (1978-10-01). "Pliocene closing of the Isthmus of Panama, based on biostratigraphic evidence from nearby Pacific Ocean and Caribbean Sea cores". Geology. 6 (10): 630–634. doi:10.1130/0091-7613(1978)62.0.CO;2. ISSN   0091-7613.
  38. Narciso Benítez, Jesús Maíz-Apellániz, and Matilde Canelles et al. (2002). "Evidence for Nearby Supernova Explosions". Phys. Rev. Lett. 88 (8): 081101. arXiv: astro-ph/0201018 . Bibcode:2002PhRvL..88h1101B. doi:10.1103/PhysRevLett.88.081101. PMID   11863949. S2CID   41229823.CS1 maint: uses authors parameter (link)
  39. Katie Pennicott (Feb 13, 2002). "Supernova link to ancient extinction". physicsworld.com. Retrieved 16 July 2012.
  40. Comins & Kaufmann (2005), p. 359.
  41. "Researchers consider whether supernovae killed off large ocean animals at dawn of Pleistocene". phys.org.
  42. "Researchers consider whether supernovae killed off large ocean animals at dawn of Pleistocene". phys.org.
  43. "Interstellar Iron Found In Antarctic Snow - Astrobiology". astrobiology.com.

Further reading