Pako Guyot

15°30′N 155°0′EPako Guyot is a guyot in the Pacific Ocean.

Bathymetry

Name

The guyot is also known as Caiwei[1] or Pallada after the Russian frigate Pallada.[2]

Geomorphology

Pako Guyot reaches a depth of 1,350 metres (4,430 ft).[3] It has dimensions of 40 by 65 kilometres (25 mi × 40 mi) and features a summit plateau 2,056 square kilometres (794 sq mi) wide[4] at a depth of 1,500–1,650 metres (4,920–5,410 ft)[3] with a shape corresponding to an irregular rectangle-triangle.[2] With an area of 13,680 square kilometres (5,280 sq mi), Pako Guyot is the third-largest guyot on Earth, only behind Koko Seamount and Suiko Seamount.[5] The summit plateau is covered by sediments 25–100 metres (82–328 ft) thick[6] including foraminiferal ooze, while the flanks feature small-scale features such as depressions, ridges and trenches.[3] Former reefs occur on the seamount[7] and during the Cretaceous and Eocene left mudstones and limestones on the seamount. Later, pelagic limestones were emplaced on them. A 65 square kilometres (25 sq mi) large area on the northwestern corner of Pako Guyot's summit plateau is free of sediments.[6]

Geology

The guyot is part of the Magellan Seamounts.[8] The seamount was volcanically active during the Cretaceous-Paleogene[9] 91.3 million years ago[10] and may have formed on a hotspot together with Ioah Guyot and Vlinder Guyot;[11] a late phase of volcanism may have taken place in the Paleocene-Eocene.[12] The hotspots that formed Pako Guyot were located in what is today French Polynesia.[6]

Volcanic rocks dredged from Pako are of sodium-potassium hawaiitic and trachybasaltic composition[2] and geochemically resemble these erupted by the Rarotonga hotspot.[13] Clays with Cenomanian-age radiolarian fossils cover the entire lower slopes of Pako Guyot.[7]

Biota

Corals and squat lobsters have been found on the seamount.[14] Ophiuroids, most of which are symbiotic with corals and sponges, live on the seamount and its flanks.[1] Diverse communities including brittle stars, corals, fish, sea anemones, sea cucumbers, sea lilies, sea urchins, shrimp and starfish have been found at its feet, where organic matter accumulates.[3] Ammonites lived on the seamount during the Cretaceous.[15]

Mining

The seamount features substantial deposits of ferromanganese and phosphorite ores.[2] In 2014, China obtained a contract with the International Seabed Authority allowing for exploration of Pako Guyot for cobalt crusts.[16]

See also

References
  1. Zhang, Dongsheng; Lu, Bo; Wang, Xiaogu; Lin, Shiquan; Wang, Chunsheng (April 2015). "Ophiuroids from the Caiwei(Pako) guyot in the northwest Pacific". EGU General Assembly Conference Abstracts. 17: 8190. Bibcode:2015EGUGA..17.8190Z.
  2. "Гайот Паллада (15°18.00' N 155°00.00' E )". Магеллановы горы (Тихий океан) (in Russian). Shirshov Institute of Oceanology. Retrieved 2018-10-06.
  3. Yang, Zifei; Qian, Qiankun; Chen, Min; Zhang, Run; Yang, Weifeng; Zheng, Minfang; Qiu, Yusheng (February 2020). "Enhanced but highly variable bioturbation around seamounts in the northwest Pacific". Deep Sea Research Part I: Oceanographic Research Papers. 156: 103190. Bibcode:2020DSRI..15603190Y. doi:10.1016/j.dsr.2019.103190. ISSN 0967-0637. S2CID 213393633.
  4. Okamoto, Nobuyuki; Usui, Akira (4 March 2014). "Regional Distribution of Co-Rich Ferromanganese Crusts and Evolution of the Seamounts in the Northwestern Pacific". Marine Georesources & Geotechnology. 32 (3): 194. doi:10.1080/1064119x.2013.877110. ISSN 1064-119X. S2CID 128677808.
  5. Harris, P.T.; Macmillan-Lawler, M.; Rupp, J.; Baker, E.K. (June 2014). "Geomorphology of the oceans". Marine Geology. 352: 4–24. Bibcode:2014MGeol.352....4H. doi:10.1016/j.margeo.2014.01.011. ISSN 0025-3227.
  6. Zhao, Bin; Wei, Zhenquan; Yang, Yong; He, Gaowen; Zhang, Heng; Ma, Weilin (20 October 2020). "Sedimentary characteristics and the implications of cobalt-rich crusts resources at Caiwei Guyot in the Western Pacific Ocean". Marine Georesources & Geotechnology. 38 (9): 1037–1045. doi:10.1080/1064119X.2019.1648615. ISSN 1064-119X. S2CID 202188742.
  7. Pletnev, S. P. (1 September 2019). "Main Types of Aptian–Cenomanian Sedimentary Rocks on Guyots of the Magellan Mountains, Pacific Ocean". Russian Journal of Pacific Geology. 13 (5): 436–445. doi:10.1134/S1819714019050087. ISSN 1819-7159. S2CID 203654288.
  8. Lee, Tae-Gook; Hein, James R.; Lee, Kiehwa; Moon, Jai-Woon; Ko, Young-Tak (October 2005). "Sub-seafloor acoustic characterization of seamounts near the Ogasawara Fracture Zone in the western Pacific using chirp (3–7kHz) subbottom profiles". Deep Sea Research Part I: Oceanographic Research Papers. 52 (10): 1934. Bibcode:2005DSRI...52.1932L. doi:10.1016/j.dsr.2005.04.009. ISSN 0967-0637.
  9. Zhao, Bin; Wei, Zhenquan; Yang, Yong; He, Gaowen; Zhang, Heng; Ma, Weilin (10 August 2019). "Sedimentary characteristics and the implications of cobalt-rich crusts resources at Caiwei Guyot in the Western Pacific Ocean". Marine Georesources & Geotechnology. 38 (9): 2. doi:10.1080/1064119X.2019.1648615. ISSN 1064-119X. S2CID 202188742.
  10. Lee, Tae-Gook; Lee, Kiehwa; Hein, James R.; Moon, Jai-Woon (March 2009). "Geophysical investigation of seamounts near the Ogasawara Fracture Zone, western Pacific". Earth, Planets and Space. 61 (3): 320. Bibcode:2009EP&S...61..319L. doi:10.1186/bf03352914. ISSN 1343-8832.
  11. Lee, Tae-Gook; Moon, Jai-Woon; Jung, Mee-Sook (April 2009). "Three-dimensional flexure modelling of seamounts near the Ogasawara Fracture Zone in the western Pacific". Geophysical Journal International. 177 (1): 249. Bibcode:2009GeoJI.177..247L. doi:10.1111/j.1365-246X.2008.04054.x. ISSN 0956-540X.
  12. Mel’nikov, M. E.; Pletnev, S. P.; Anokhin, V. M.; Sedysheva, T. E.; Ivanov, V. V. (November 2016). "Volcanic edifices on guyots of the Magellan Seamounts (Pacific Ocean)". Russian Journal of Pacific Geology. 10 (6): 439. doi:10.1134/s1819714016060038. ISSN 1819-7140. S2CID 132364693.
  13. Koppers, Anthony A. P.; Staudigel, Hubert; Pringle, Malcolm S.; Wijbrans, Jan R. (October 2003). "Short-lived and discontinuous intraplate volcanism in the South Pacific: Hot spots or extensional volcanism?". Geochemistry, Geophysics, Geosystems. 4 (10): 1089. Bibcode:2003GGG.....4.1089K. doi:10.1029/2003gc000533. ISSN 1525-2027. S2CID 131213793.
  14. DONG, DONG; LI, XINZHENG; LU, BO; WANG, CHUNSHENG (24 August 2017). "Three squat lobsters (Crustacea: Decapoda: Anomura) from tropical West Pacific seamounts, with description of a new species of Uroptychus Henderson, 1888". Zootaxa. 4311 (3): 389. doi:10.11646/zootaxa.4311.3.4.
  15. Zakharov, Yuri D.; Melnikov, Mikhael E.; Popov, Alexander M.; Pletnev, Sergej P.; Khudik, Vladimir D.; Punina, Tatiana A. (January 2012). "Cephalopod and brachiopod fossils from the Pacific: Evidence from the Upper Cretaceous of the Magellan Seamounts". Geobios. 45 (1): 145–156. doi:10.1016/j.geobios.2011.11.011. ISSN 0016-6995.
  16. Zhao, Bin; Wei, Zhenquan; Yang, Yong; He, Gaowen; Zhang, Heng; Ma, Weilin (10 August 2019). "Sedimentary characteristics and the implications of cobalt-rich crusts resources at Caiwei Guyot in the Western Pacific Ocean". Marine Georesources & Geotechnology. 38 (9): 1. doi:10.1080/1064119X.2019.1648615. ISSN 1064-119X. S2CID 202188742.


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