Paleoproterozoic Explained

Paleoproterozoic
Color:Paleoproterozoic
Top Bar:all time
Time Start:2500
Time End:1600
Caption Map:Paleoproterozoic stromatolites
Timeline:Paleoproterozoic
Proposed Boundaries1:2420–1780 Ma
Proposed Boundaries1 Ref:Gradstein et al., 2012
Proposed Subdivision1:Oxygenian Period, 2420–2250 Ma
Proposed Subdivision1 Coined:Gradstein et al., 2012
Proposed Subdivision2:Jatulian/Eukaryian Period, 2250–2060 Ma
Proposed Subdivision2 Coined:Gradstein et al., 2012
Proposed Subdivision3:Columbian Period, 2060–1780 Ma
Proposed Subdivision3 Coined:Gradstein et al., 2012
Name Formality:Formal
Alternate Spellings:Palaeoproterozoic
Celestial Body:earth
Usage:Global (ICS)
Timescales Used:ICS Time Scale
Chrono Unit:Era
Strat Unit:Erathem
Timespan Formality:Formal
Lower Boundary Def:Defined Chronometrically
Lower Gssa Accept Date:1991[1]
Upper Boundary Def:Defined Chronometrically
Upper Gssa Accept Date:1991

The Paleoproterozoic Era (also spelled Palaeoproterozoic) is the first of the three sub-divisions (eras) of the Proterozoic eon, and also the longest era of the Earth's geological history, spanning from (2.5–1.6 Ga). It is further subdivided into four geologic periods, namely the Siderian, Rhyacian, Orosirian and Statherian.

Paleontological evidence suggests that the Earth's rotational rate ~1.8 billion years ago equated to 20-hour days, implying a total of ~450 days per year.[2] It was during this era that the continents first stabilized.

Atmosphere

See main article: Prebiotic atmosphere, Geological history of oxygen and Great Oxygenation Event. The Earth's atmosphere was originally a weakly reducing atmosphere consisting largely of nitrogen, methane, ammonia, carbon dioxide and inert gases, in total comparable to Titan's atmosphere.[3] When oxygenic photosynthesis evolved in cyanobacteria during the Mesoarchean, the increasing amount of byproduct dioxygen began to deplete the reductants in the ocean, land surface and the atmosphere. Eventually all surface reductants (particularly ferrous iron, sulfur and atmospheric methane) were exhausted, and the atmospheric free oxygen levels soared permanently during the Siderian and Rhyacian periods in an aerochemical event called the Great Oxidation Event, which brought atmospheric oxygen from near none to up to 10% of the modern level.[4]

Life

See also: Symbiogenesis. At the beginning of the preceding Archean eon, almost all existing lifeforms were single-cell prokaryotic anaerobic organisms whose metabolism was based on a form of cellular respiration that did not require oxygen, and autotrophs were either chemosynthetic or relied upon anoxygenic photosynthesis. After the Great Oxygenation Event, the then mainly archaea-dominated anaerobic microbial mats were devastated as free oxygen is highly reactive and biologically toxic to cellular structures. This was compounded by a 300-million-year-long global icehouse event known as the Huronian glaciation — at least partly due to the depletion of atmospheric methane, a powerful greenhouse gas — resulted in what is widely considered one of the first and most significant mass extinctions on Earth.[5] [6] The organisms that thrived after the extinction were mainly aerobes that evolved bioactive antioxidants and eventually aerobic respiration, and surviving anaerobes were forced to live symbiotically alongside aerobes in hybrid colonies, which enabled the evolution of mitochondria in eukaryotic organisms.

The Palaeoproterozoic represents the era from which the oldest cyanobacterial fossils, those of Eoentophysalis belcherensis from the Kasegalik Formation in the Belcher Islands of Nunavut, are known.[7] By 1.75 Ga, thylakoid-bearing cyanobacteria had evolved, as evidenced by fossils from the McDermott Formation of Australia.[8]

Many crown node eukaryotes (from which the modern-day eukaryotic lineages would have arisen) have been approximately dated to around the time of the Paleoproterozoic Era.[9] [10] [11] While there is some debate as to the exact time at which eukaryotes evolved,[12] [13] current understanding places it somewhere in this era.[14] [15] [16] Statherian fossils from the Changcheng Group in North China provide evidence that eukaryotic life was already diverse by the late Palaeoproterozoic.[17]

Geological events

During this era, the earliest global-scale continent-continent collision belts developed. The associated continent and mountain building events are represented by the 2.1–2.0 Ga Trans-Amazonian and Eburnean orogens in South America and West Africa; the ~2.0 Ga Limpopo Belt in southern Africa; the 1.9–1.8 Ga Trans-Hudson, Penokean, Taltson–Thelon, Wopmay, Ungava and Torngat orogens in North America, the 1.9–1.8 Ga Nagssugtoqidian Orogen in Greenland; the 1.9–1.8 Ga Kola–Karelia, Svecofennian, Volhyn-Central Russian, and Pachelma orogens in Baltica (Eastern Europe); the 1.9–1.8 Ga Akitkan Orogen in Siberia; the ~1.95 Ga Khondalite Belt; the ~1.85 Ga Trans-North China Orogen in North China; and the 1.8-1.6 Ga Yavapai and Mazatzal orogenies in southern North America.

That pattern of collision belts supports the formation of a Proterozoic supercontinent named Columbia or Nuna.[18] [19] That continental collisions suddenly led to mountain building at large scale is interpreted as having resulted from increased biomass and carbon burial during and after the Great Oxidation Event: Subducted carbonaceous sediments are hypothesized to have lubricated compressive deformation and led to crustal thickening.[20]

Felsic volcanism in what is now northern Sweden led to the formation of the Kiruna and Arvidsjaur porphyries.[21]

The lithospheric mantle of Patagonia's oldest blocks formed.[22]

See also

External links

Notes and References

  1. Plumb . K. A. . June 1, 1991 . New Precambrian time scale . Episodes . 10.18814/epiiugs/1991/v14i2/005 . 14 . 2 . 139–140. free .
  2. Pannella . Giorgio . 1972 . Paleontological evidence on the Earth's rotational history since early precambrian . . 16 . 2. 212 . 10.1007/BF00642735 . 1972Ap&SS..16..212P. 122908383 .
  3. Trainer . Melissa G. . Pavlov . Alexander A. . DeWitt . H. Langley . Jimenez . Jose L. . McKay . Christopher P. . Toon . Owen B. . Tolbert . Margaret A. . Organic haze on Titan and the early Earth . Proceedings of the National Academy of Sciences . 103 . 48 . 2006-11-28 . 0027-8424 . 10.1073/pnas.0608561103 . 18035–18042. 17101962 . 1838702 . free .
  4. Ossa Ossa . Frantz . Spangenberg . Jorge E. . Bekker . Andrey . König . Stephan . Stüeken . Eva E. . Hofmann . Axel . Poulton . Simon W. . Yierpan . Aierken . Varas-Reus . Maria I. . Eickmann . Benjamin . Andersen . Morten B. . Schoenberg . Ronny . 15 September 2022 . Moderate levels of oxygenation during the late stage of Earth's Great Oxidation Event . . 594 . 117716 . 10.1016/j.epsl.2022.117716 . free . 10481/78482 . free .
  5. Hodgskiss . Malcolm S. W. . Crockford . Peter W. . Peng . Yongbo . Wing . Boswell A. . Horner . Tristan J. . 27 August 2019 . A productivity collapse to end Earth's Great Oxidation . . dmy-all . 116 . 35 . 17207–17212 . 10.1073/pnas.1900325116 . free . 31405980 . 6717284 . 2019PNAS..11617207H.
  6. Book: Microcosmos: Four Billion Years of Microbial Evolution . Margulis . Lynn . Lynn Margulis . Sagan . Dorion . Dorion Sagan . 1997-05-29 . University of California Press . 9780520210646 . en .
  7. Hodgskiss . Malcolm S.W. . Dagnaud . Olivia M.J. . Frost . Jamie L. . Halverson . Galen P. . Schmitz . Mark D. . Swanson-Hysell . Nicholas L. . Sperling . Erik A. . 15 August 2019 . New insights on the Orosirian carbon cycle, early Cyanobacteria, and the assembly of Laurentia from the Paleoproterozoic Belcher Group . . en . 520 . 141–152 . 10.1016/j.epsl.2019.05.023 . 18 May 2024 . Elsevier Science Direct.
  8. Demoulin . Catherine F. . Lara . Yannick J. . Lambion . Alexandre . Javaux . Emmanuelle J. . 18 January 2024 . Oldest thylakoids in fossil cells directly evidence oxygenic photosynthesis . . en . 625 . 7995 . 529–534 . 10.1038/s41586-023-06896-7 . 0028-0836 . 24 June 2024.
  9. Mänd . Kaarel . Planavsky . Noah J. . Porter . Susannah M. . Robbins . Leslie J. . Wang . Changle . Kraitsmann . Timmu . Paiste . Kärt . Paiste . Päärn . Romashkin . Alexander E. . Deines . Yulia E. . Kirsimäe . Kalle . Lepland . Aivo . Konhauser . Kurt O. . 15 April 2022 . Chromium evidence for protracted oxygenation during the Paleoproterozoic . . 584 . 117501 . 10.1016/j.epsl.2022.117501 . 15 December 2022. 10037/24808 . free .
  10. Hedges. S Blair. Chen. Hsiong. Kumar. Sudhir. Wang. Daniel YC. Thompson. Amanda S. Watanabe. Hidemi. 2001-09-12. A genomic timescale for the origin of eukaryotes. BMC Evolutionary Biology. 1. 4. 10.1186/1471-2148-1-4. 1471-2148. 11580860. 56995 . free .
  11. Hedges. S Blair. Blair. Jaime E. Venturi. Maria L. Shoe. Jason L. 2004-01-28. A molecular timescale of eukaryote evolution and the rise of complex multicellular life. BMC Evolutionary Biology. 4. 2. 10.1186/1471-2148-4-2. 1471-2148. 15005799. 341452 . free .
  12. Rodríguez-Trelles. Francisco. Tarrío. Rosa. Ayala. Francisco J.. 2002-06-11. A methodological bias toward overestimation of molecular evolutionary time scales. Proceedings of the National Academy of Sciences of the United States of America. 99. 12. 8112–8115. 10.1073/pnas.122231299. 0027-8424. 12060757. 123029. 2002PNAS...99.8112R. free.
  13. Stechmann. Alexandra. Cavalier-Smith. Thomas. 2002-07-05. Rooting the eukaryote tree by using a derived gene fusion. Science. 297. 5578. 89–91. 10.1126/science.1071196. 1095-9203. 12098695. 2002Sci...297...89S. 21064445.
  14. Ayala. Francisco José. Rzhetsky. Andrey. Ayala. Francisco J.. 1998-01-20. Origin of the metazoan phyla: Molecular clocks confirm paleontological estimates. Proceedings of the National Academy of Sciences of the United States of America. 95. 2. 606–611. 0027-8424. 9435239. 18467. 10.1073/pnas.95.2.606. 1998PNAS...95..606J. free.
  15. Wang. D Y. Kumar. S. Hedges. S B. 1999-01-22. Divergence time estimates for the early history of animal phyla and the origin of plants, animals and fungi.. Proceedings of the Royal Society B: Biological Sciences. 266. 1415. 163–171. 1689654. 10097391. 10.1098/rspb.1999.0617.
  16. Javaux . Emmanuelle J. . Lepot . Kevin . January 2018 . The Paleoproterozoic fossil record: Implications for the evolution of the biosphere during Earth's middle-age . . 176 . 68–86 . 10.1016/j.earscirev.2017.10.001 . free . 20.500.12210/62416 . free .
  17. Miao . Lanyun . Moczydłowska . Małgorzata . Zhu . Shixing . Zhu . Maoyan . February 2019 . New record of organic-walled, morphologically distinct microfossils from the late Paleoproterozoic Changcheng Group in the Yanshan Range, North China . . 321 . 172–198 . 10.1016/j.precamres.2018.11.019 . 134362289 . 29 December 2022.
  18. Zhao. Guochun. Cawood. Peter A. Wilde. Simon A. Sun. Min. 2002. Review of global 2.1–1.8 Ga orogens: implications for a pre-Rodinia supercontinent . Earth-Science Reviews . 59 . 1–4. 125–162. 10.1016/S0012-8252(02)00073-9. 2002ESRv...59..125Z .
  19. Guochun . Zhao . Sun, M. . Wilde, Simon A. . Li, S.Z. . 2004. A Paleo-Mesoproterozoic supercontinent: assembly, growth and breakup . Earth-Science Reviews . 67 . 1–2 . 91–123. 10.1016/j.earscirev.2004.02.003. 2004ESRv...67...91Z .
  20. John Parnell, Connor Brolly: Increased biomass and carbon burial 2 billion years ago triggered mountain building. Nature Communications Earth & Environment, 2021, (Open Access).
  21. Book: Lundqvist . Thomas. Thomas Lundqvist (geologist) . 2009 . Porfyr i Sverige: En geologisk översikt . 978-91-7158-960-6 . sv . 24–27. Sveriges geologiska undersökning .
  22. Schilling . Manuel Enrique . Carlson . Richard Walter. Tassara . Andrés. Conceição . Rommulo Viveira. Berotto . Gustavo Walter. Vásquez . Manuel. Muñoz. Daniel . Jalowitzki . Tiago. Gervasoni . Fernanda. Morata . Diego . 2017 . The origin of Patagonia revealed by Re-Os systematics of mantle xenoliths . . 294 . 15–32 . 10.1016/j.precamres.2017.03.008. 2017PreR..294...15S. 11336/19304 . free .

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