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Sierra Leone hotspot

January 01, 1970

Sierra Leone hotspot is a proposed hotspot in the Atlantic Ocean.

The existence of this hotspot has been inferred from the Sierra Leone Rise and the Ceara Rise in the Atlantic Ocean,[1] two submarine topographic features around the 5th parallel north.[2] They formed as a single oceanic plateau that was subsequently split by the Mid-Atlantic Ridge[1] during the Jurassic and Cretaceous (Aptian).[2]

According to the proposal by Basile et al. 2020, the Sierra Leone hotspot 201 million years ago was at the centre of the Central Atlantic Magmatic Province, north of the Blake Plateau off North America.[3] The hotspot 180-170 million years ago formed a first oceanic plateau that was subsequently split by the Mid-Atlantic Ridge around 100 million years ago, forming the Demerara Plateau and Guinea Rise. Between 90-70 million years ago the hotspot was under the African Plate, forming the northern Bathymetrists Seamounts. The Mid-Atlantic Ridge eventually reached the hotspot, resulting 82-55 million years ago in the formation of a second oceanic plateau which was again split by the Mid-Atlantic Ridge to form the Ceara Rise and Sierra Leone Rise. Since then, the Sierra Leone hotspot would have been again located on the African Plate, now generating the southern group of the Bathymetrists Seamounts. 10 million years ago it generated the Knipovich seamount.[4]

The hotspot is currently located about 100 kilometres (62 mi) west of Knipovich seamount;[5] it is presently inactive.[1] According to an alternative proposal by Long et al. 2020, the hotspot would now be centered on 5°17′N 25°18′W / 5.28°N 25.3°W / 5.28; -25.3 above a seismic velocity anomaly in the mantle and in a cluster of seamounts.[6]

Other structures influenced by the hotspot:

  • Bahamas may be a hotspot track of the Sierra Leone hotspot, which between 170-155 million years ago may have been active on the North American Plate.[7]
  • The east-west trending Bathymetrists Seamounts[5] north of the Sierra Leone Rise.[2] They were capped by carbonates during the mid-Eocene.[5] Some of the northern seamounts however produce problems in plate tectonic reconstructions if they are correlated to the Sierra Leone hotspot.[8]
  • Syenites on the Îles de Los may be a product of the hotspot.[3]
  • Certain segments of the Mid-Atlantic Ridge may be influenced by the hotspot.[9]
  • Knipovich seamount rises to a depth of 600 metres (2,000 ft) below sea level and has a 12 by 6 kilometres (7.5 mi × 3.7 mi) summit.[5]
  • Plate motion changes during the Paleocene may be driven by the torque from the Sierra Leone hotspot.[10]

References edit

  1. ^ a b c Basile et al. 2020, p. 1.
  2. ^ a b c Basile et al. 2020, p. 2.
  3. ^ a b Basile et al. 2020, p. 9.
  4. ^ Basile et al. 2020, pp. 7–8.
  5. ^ a b c d Basile et al. 2020, p. 3.
  6. ^ Long et al. 2020, p. 16.
  7. ^ Basile et al. 2020, p. 8.
  8. ^ Long et al. 2020, p. 15.
  9. ^ Peterson et al. 2014, p. 2205.
  10. ^ Stotz et al. 2023, p. 6.

Sources edit

  • Basile, Christophe; Girault, Igor; Paquette, Jean-Louis; Agranier, Arnaud; Loncke, Lies; Heuret, Arnauld; Poetisi, Ewald (4 May 2020). "The Jurassic magmatism of the Demerara Plateau (offshore French Guiana) as a remnant of the Sierra Leone hotspot during the Atlantic rifting". Scientific Reports. 10 (1): 7486. Bibcode:2020NatSR..10.7486B. doi:10.1038/s41598-020-64333-5. ISSN 2045-2322. PMC 7198611. PMID 32366924.
  • Long, Xiaojun; van der Zwan, Froukje M.; Geldmacher, Jörg; Hoernle, Kaj; Hauff, Folkmar; Garbe-Schönberg, C. -Dieter; Augustin, Nico (30 June 2020). "Insights into the petrogenesis of an intraplate volcanic province: Sr-Nd-Pb-Hf isotope geochemistry of the Bathymetrists Seamount Province, eastern equatorial Atlantic". Chemical Geology. 544: 119599. Bibcode:2020ChGeo.544k9599L. doi:10.1016/j.chemgeo.2020.119599. hdl:10754/666861. ISSN 0009-2541. S2CID 216224524.
  • Peterson, M. E.; Saal, A. E.; Nakamura, E.; Kitagawa, H.; Kurz, M. D.; Koleszar, A. M. (1 November 2014). "Origin of the 'Ghost Plagioclase' Signature in Galapagos Melt Inclusions: New Evidence from Pb Isotopes". Journal of Petrology. 55 (11): 2193–2216. doi:10.1093/petrology/egu054. ISSN 0022-3530.
  • Stotz, Ingo L.; Vilacís, Berta; Hayek, Jorge N.; Carena, Sara; Bunge, Hans-Peter (April 2023). "Plume driven plate motion changes: New insights from the South Atlantic realm". Journal of South American Earth Sciences. 124: 104257. doi:10.1016/j.jsames.2023.104257.

January 01, 1970
sierra, leone, hotspot, proposed, hotspot, atlantic, ocean, existence, this, hotspot, been, inferred, from, sierra, leone, rise, ceara, rise, atlantic, ocean, submarine, topographic, features, around, parallel, north, they, formed, single, oceanic, plateau, th. Sierra Leone hotspot is a proposed hotspot in the Atlantic Ocean The existence of this hotspot has been inferred from the Sierra Leone Rise and the Ceara Rise in the Atlantic Ocean 1 two submarine topographic features around the 5th parallel north 2 They formed as a single oceanic plateau that was subsequently split by the Mid Atlantic Ridge 1 during the Jurassic and Cretaceous Aptian 2 According to the proposal by Basile et al 2020 the Sierra Leone hotspot 201 million years ago was at the centre of the Central Atlantic Magmatic Province north of the Blake Plateau off North America 3 The hotspot 180 170 million years ago formed a first oceanic plateau that was subsequently split by the Mid Atlantic Ridge around 100 million years ago forming the Demerara Plateau and Guinea Rise Between 90 70 million years ago the hotspot was under the African Plate forming the northern Bathymetrists Seamounts The Mid Atlantic Ridge eventually reached the hotspot resulting 82 55 million years ago in the formation of a second oceanic plateau which was again split by the Mid Atlantic Ridge to form the Ceara Rise and Sierra Leone Rise Since then the Sierra Leone hotspot would have been again located on the African Plate now generating the southern group of the Bathymetrists Seamounts 10 million years ago it generated the Knipovich seamount 4 The hotspot is currently located about 100 kilometres 62 mi west of Knipovich seamount 5 it is presently inactive 1 According to an alternative proposal by Long et al 2020 the hotspot would now be centered on 5 17 N 25 18 W 5 28 N 25 3 W 5 28 25 3 above a seismic velocity anomaly in the mantle and in a cluster of seamounts 6 Other structures influenced by the hotspot Bahamas may be a hotspot track of the Sierra Leone hotspot which between 170 155 million years ago may have been active on the North American Plate 7 The east west trending Bathymetrists Seamounts 5 north of the Sierra Leone Rise 2 They were capped by carbonates during the mid Eocene 5 Some of the northern seamounts however produce problems in plate tectonic reconstructions if they are correlated to the Sierra Leone hotspot 8 Syenites on the Iles de Los may be a product of the hotspot 3 Certain segments of the Mid Atlantic Ridge may be influenced by the hotspot 9 Knipovich seamount rises to a depth of 600 metres 2 000 ft below sea level and has a 12 by 6 kilometres 7 5 mi 3 7 mi summit 5 Plate motion changes during the Paleocene may be driven by the torque from the Sierra Leone hotspot 10 References edit a b c Basile et al 2020 p 1 a b c Basile et al 2020 p 2 a b Basile et al 2020 p 9 Basile et al 2020 pp 7 8 a b c d Basile et al 2020 p 3 Long et al 2020 p 16 Basile et al 2020 p 8 Long et al 2020 p 15 Peterson et al 2014 p 2205 Stotz et al 2023 p 6 Sources edit Basile Christophe Girault Igor Paquette Jean Louis Agranier Arnaud Loncke Lies Heuret Arnauld Poetisi Ewald 4 May 2020 The Jurassic magmatism of the Demerara Plateau offshore French Guiana as a remnant of the Sierra Leone hotspot during the Atlantic rifting Scientific Reports 10 1 7486 Bibcode 2020NatSR 10 7486B doi 10 1038 s41598 020 64333 5 ISSN 2045 2322 PMC 7198611 PMID 32366924 Long Xiaojun van der Zwan Froukje M Geldmacher Jorg Hoernle Kaj Hauff Folkmar Garbe Schonberg C Dieter Augustin Nico 30 June 2020 Insights into the petrogenesis of an intraplate volcanic province Sr Nd Pb Hf isotope geochemistry of the Bathymetrists Seamount Province eastern equatorial Atlantic Chemical Geology 544 119599 Bibcode 2020ChGeo 544k9599L doi 10 1016 j chemgeo 2020 119599 hdl 10754 666861 ISSN 0009 2541 S2CID 216224524 Peterson M E Saal A E Nakamura E Kitagawa H Kurz M D Koleszar A M 1 November 2014 Origin of the Ghost Plagioclase Signature in Galapagos Melt Inclusions New Evidence from Pb Isotopes Journal of Petrology 55 11 2193 2216 doi 10 1093 petrology egu054 ISSN 0022 3530 Stotz Ingo L Vilacis Berta Hayek Jorge N Carena Sara Bunge Hans Peter April 2023 Plume driven plate motion changes New insights from the South Atlantic realm Journal of South American Earth Sciences 124 104257 doi 10 1016 j jsames 2023 104257 Retrieved from https en wikipedia org w index php title Sierra Leone hotspot amp oldid 1191124322, wikipedia, wiki, book, books, library,

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