To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
.
Leo
Newton
Brights
Milds

From Wikipedia, the free encyclopedia

Paleogene Period
66–23.03 million years ago
Mean atmospheric O
2
content over period duration
c. 26 vol %[1][2]
(130 % of modern level)
Mean atmospheric CO
2
content over period duration
c. 500 ppm[3]
(2 times pre-industrial level)
Mean surface temperature over period duration c. 18 °C[4]
(4 °C above modern level)
Key events in the Paleogene
-65 —
-60 —
-55 —
-50 —
-45 —
-40 —
-35 —
-30 —
-25 —
N. Amer. prairie expands[5]
An approximate timescale of key Paleogene events.
Axis scale: millions of years ago.

The Paleogene (/ˈpæliən, ˈpliə-/; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period 66 million years ago (Mya) to the beginning of the Neogene Period 23.03 Mya. It is the beginning of the Cenozoic Era of the present Phanerozoic Eon.[7] The Paleogene is most notable for being the time during which mammals diversified from relatively small, simple forms into a large group of diverse animals in the wake of the Cretaceous–Paleogene extinction event that ended the preceding Cretaceous Period.[8] The United States Geological Survey uses the abbreviation PE for the Paleogene,[9][10] but the more commonly used abbreviation is PG with the PE being used for Paleocene.

This period consists of the Paleocene, Eocene, and Oligocene epochs. The end of the Paleocene (55.5/54.8 Mya) was marked by the Paleocene–Eocene Thermal Maximum, one of the most significant periods of global change during the Cenozoic, which upset oceanic and atmospheric circulation and led to the extinction of numerous deep-sea benthic foraminifera and on land, a major turnover in mammals. The terms 'Paleogene System' (formal) and 'lower Tertiary System' (informal) are applied to the rocks deposited during the 'Paleogene Period'. The somewhat confusing terminology seems to be due to attempts to deal with the comparatively fine subdivisions of time possible in the relatively recent geologic past, for which more details are preserved. When the Tertiary Period is divided into two periods instead of directly into five epochs, the periods are more closely comparable to the duration of 'periods' of the preceding Mesozoic and Paleozoic Eras.

YouTube Encyclopedic

  • 1/5
    Views:
    1 908
    304 746
    305 062
    1 032 077
    2 451 463
  • ✪ What was life like during the Paleogene Time Period ?
  • ✪ Evolution of Life After the Dinosaur Extinction
  • ✪ How Many Mass Extinctions Have Happened On Earth?
  • ✪ The Day the Mesozoic Died: The Asteroid That Killed the Dinosaurs — HHMI BioInteractive Video
  • ✪ Experience the Disaster that Wiped Out Dinosaurs

Transcription

Welcome to MooMooMath and Science In this video, I would like to talk about the Paleogene Time Period Paleogene Time Period The Paleogene time period is part of the Cenozoic era. It lasted from 65 million to 23 million years ago. The climate at the beginning of the Paleogene time was tropical. This resulted in mammals, birds, and insects to scatter throughout the world. Mammals prospered during this time. Many of the animals we like today including dogs, cats, and pigs appeared in the Paleogene. Sharks and whales roamed the ocean and freshwater fish branched out. With the growth of insects, including bees flowering plants began to spread throughout the world. Monkeys begin to appear. There were also several important geological events The Himalaya mountains were created North America and Europe separate and sea levels were low. At the end of the Paleogene climates begin to cool. So there you go, the Paleogene time period Thanks for watching and MooMooMath and Science uploads a new Math and Science video every day

Contents

Climate and geography

The global climate during the Paleogene departed from the hot and humid conditions of the late Mesozoic era and began a cooling and drying trend which, despite having been periodically disrupted by warm periods such as the Paleocene–Eocene Thermal Maximum,[11] persisted until the temperature begun to rise again due to anthropogenic influences at around 1945. The trend was partly caused by the formation of the Antarctic Circumpolar Current, which significantly lowered oceanic water temperatures. A 2018 published study estimated that during the early Palaeogene about 56-48 million years ago, annual air temperatures, over land and at mid-latitude, averaged about 23–29 °C (± 4.7 °C), which is 5–10 °C higher than most previous estimates.[12][13] Or for comparison, it was 10 to 15 °C higher than current annual mean temperatures in these areas; the authors suggest that the current atmospheric carbon dioxide trajectory, if it continues, could establish these temperatures again.[14]

During the Paleogene, the continents continued to drift closer to their current positions. India was in the process of colliding with Asia, forming the Himalayas. The Atlantic Ocean continued to widen by a few centimeters each year. Africa was moving north to meet with Europe and form the Mediterranean Sea, while South America was moving closer to North America (they would later connect via the Isthmus of Panama). Inland seas retreated from North America early in the period. Australia had also separated from Antarctica and was drifting toward Southeast Asia.

Flora and fauna

Mammals began a rapid diversification during this period. After the Cretaceous–Paleogene extinction event, which saw the demise of the non-avian dinosaurs, mammals transformed from a few small and generalized forms that began to evolve into most of the modern varieties we see today. Some of these mammals would evolve into large forms that would dominate the land, while others would become capable of living in marine, specialized terrestrial, and airborne environments. Those that took to the oceans became modern cetaceans, while those that took to the trees became primates, the group to which humans belong. Birds, which were already well established by the end of the Cretaceous, also experienced an adaptive radiation as they took over the skies left empty by the now extinct Pterosaurs.

Pronounced cooling in the Oligocene led to a massive floral shift and many extant modern plants arose during this time. Grasses and herbs such as Artemisia began to appear at the expense of tropical plants, which began to decline. Conifer forests developed in mountainous areas. This cooling trend continued, with major fluctuation, until the end of the Pleistocene.[15] This evidence for this floral shift is found in the palynological record.[16]

Geology

Oil industry relevance

The Paleogene is notable in the context of offshore oil drilling, and especially in Gulf of Mexico oil exploration, where it is commonly referred to as the "Lower Tertiary". These rock formations represent the current cutting edge of deep-water oil discovery.

Lower Tertiary rock formations encountered in the Gulf of Mexico oil industry usually tend to be comparatively high temperature and high pressure reservoirs, often with high sand content (70%+) or under very thick evaporite sediment layers.[17]

Lower Tertiary explorations include (partial list):

References

  1. ^ Image:Sauerstoffgehalt-1000mj.svg
  2. ^ File:OxygenLevel-1000ma.svg
  3. ^ Image:Phanerozoic Carbon Dioxide.png
  4. ^ Image:All palaeotemps.png
  5. ^ 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.
  6. ^ Zachos, J. C.; Kump, L. R. (2005). "Carbon cycle feedbacks and the initiation of Antarctic glaciation in the earliest Oligocene". Global and Planetary Change. 47 (1): 51–66. Bibcode:2005GPC....47...51Z. doi:10.1016/j.gloplacha.2005.01.001.
  7. ^ Formerly, the period covered by the Paleogene was called the first part of the Tertiary, whose usage is no longer official. "Whatever happened to the Tertiary and Quaternary?"
  8. ^ Robert W. Meredith, Jan E. Janecka, John Gatesy, Oliver A. Ryder, Colleen A. Fisher, Emma C. Teeling, Alisha Goodbla, Eduardo Eizirik, Taiz L. L. Simão, Tanja Stadler, Daniel L. Rabosky, Rodney L. Honeycutt, John J. Flynn, Colleen M. Ingram, Cynthia Steiner, Tiffani L. Williams, Terence J. Robinson, Angela Burk-Herrick, Michael Westerman, Nadia A. Ayoub, Mark S. Springer, William J. Murphy. 2011. Impacts of the Cretaceous Terrestrial Revolution and KPg extinction on mammal diversification. Science 334:521-524.
  9. ^ https://ngmdb.usgs.gov/fgdc_gds/geolsymstd/fgdc-geolsym-sec32.pdf
  10. ^ https://pubs.usgs.gov/fs/2007/3015/fs2007-3015.pdf
  11. ^ Wing, S. L. (2005-11-11). "Transient Floral Change and Rapid Global Warming at the Paleocene-Eocene Boundary". Science. 310 (5750): 993–996. doi:10.1126/science.1116913. ISSN 0036-8075.
  12. ^ Naafs et al. (2018). "High temperatures in the terrestrial mid-latitudes during the early Palaeogene". Nature Geoscience. 11 (10): 766–771. doi:10.1038/s41561-018-0199-0.CS1 maint: Uses authors parameter (link)
  13. ^ University of Bristol (30 July 2018). "Ever-increasing CO2 levels could take us back to the tropical climate of Paleogene period". ScienceDaily.
  14. ^ "Ever-increasing CO2 levels could take us back to the tropical climate of Paleogene period". University of Bristol. 2018.
  15. ^ 1925-, Traverse, Alfred (1988). Paleopalynology. Unwin Hyman. ISBN 978-0045610013. OCLC 17674795.
  16. ^ Muller, Jan (January 1981). "Fossil pollen records of extant angiosperms". The Botanical Review. 47 (1): 1–142. doi:10.1007/bf02860537. ISSN 0006-8101.
  17. ^ "Lower Tertiary". Halliburton. Archived from the original on 2011-09-29. Retrieved 2011-07-13.

External links

This page was last edited on 21 March 2019, at 15:49
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.