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Nature and Origin of Magnetic Lineations Within Valdivia Bank : Ocean Plateau Formation by Complex Seafloor Spreading

Thoram, S. ; Sager, W. W. ; Gaastra, K. ; Tikoo, S. M. ; Carvallo, C. ; Avery, A. ; Del Gaudio, Arianna V. ; Huang, Y. ; Hoernle, K. and Höfig, T. W. , et al. (2023) In Geophysical Research Letters 50(13).
Abstract

Valdivia Bank (VB) is a Late Cretaceous oceanic plateau formed by volcanism from the Tristan-Gough hotspot at the Mid-Atlantic Ridge (MAR). To better understand its origin and evolution, magnetic data were used to generate a magnetic anomaly grid, which was inverted to determine crustal magnetization. The magnetization model reveals quasi-linear polarity zones crossing the plateau and following expected MAR paleo-locations, implying formation by seafloor spreading over ∼4 Myr during the formation of anomalies C34n-C33r. Paleomagnetism and biostratigraphy data from International Ocean Discovery Program Expedition 391 confirm the magnetic interpretation. Anomaly C33r is split into two negative bands, likely by a westward ridge jump. One... (More)

Valdivia Bank (VB) is a Late Cretaceous oceanic plateau formed by volcanism from the Tristan-Gough hotspot at the Mid-Atlantic Ridge (MAR). To better understand its origin and evolution, magnetic data were used to generate a magnetic anomaly grid, which was inverted to determine crustal magnetization. The magnetization model reveals quasi-linear polarity zones crossing the plateau and following expected MAR paleo-locations, implying formation by seafloor spreading over ∼4 Myr during the formation of anomalies C34n-C33r. Paleomagnetism and biostratigraphy data from International Ocean Discovery Program Expedition 391 confirm the magnetic interpretation. Anomaly C33r is split into two negative bands, likely by a westward ridge jump. One of these negative anomalies coincides with deep rift valleys, indicating their age and mechanism of formation. These findings imply that VB originated by seafloor spreading-type volcanism during a plate reorganization, not from a vertical stack of lava flows as expected for a large volcano.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
hotspot-ridge interaction, International Ocean Discovery Program (IODP) Expedition 391, magnetic anomalies, oceanic plateau, Valdivia Bank, Walvis Ridge
in
Geophysical Research Letters
volume
50
issue
13
article number
e2023GL103415
publisher
American Geophysical Union (AGU)
external identifiers
  • scopus:85165447479
ISSN
0094-8276
DOI
10.1029/2023GL103415
language
English
LU publication?
yes
id
b94bc89f-ccf9-473b-bf32-f50aa4a159a5
date added to LUP
2023-09-11 12:29:49
date last changed
2023-09-11 12:29:49
@article{b94bc89f-ccf9-473b-bf32-f50aa4a159a5,
  abstract     = {{<p>Valdivia Bank (VB) is a Late Cretaceous oceanic plateau formed by volcanism from the Tristan-Gough hotspot at the Mid-Atlantic Ridge (MAR). To better understand its origin and evolution, magnetic data were used to generate a magnetic anomaly grid, which was inverted to determine crustal magnetization. The magnetization model reveals quasi-linear polarity zones crossing the plateau and following expected MAR paleo-locations, implying formation by seafloor spreading over ∼4 Myr during the formation of anomalies C34n-C33r. Paleomagnetism and biostratigraphy data from International Ocean Discovery Program Expedition 391 confirm the magnetic interpretation. Anomaly C33r is split into two negative bands, likely by a westward ridge jump. One of these negative anomalies coincides with deep rift valleys, indicating their age and mechanism of formation. These findings imply that VB originated by seafloor spreading-type volcanism during a plate reorganization, not from a vertical stack of lava flows as expected for a large volcano.</p>}},
  author       = {{Thoram, S. and Sager, W. W. and Gaastra, K. and Tikoo, S. M. and Carvallo, C. and Avery, A. and Del Gaudio, Arianna V. and Huang, Y. and Hoernle, K. and Höfig, T. W. and Bhutani, R. and Buchs, D. M. and Class, C. and Dai, Y. and Valle, G. Dalla and Fielding, S. and Han, S. and Heaton, D. E. and Homrighausen, S. and Kubota, Y. and Li, C. F. and Nelson, W. R. and Petrou, E. and Potter, K. E. and Pujatti, S. and Scholpp, J. and Shervais, J. W. and Tshiningayamwe, M. and Wang, X. J. and Widdowson, M.}},
  issn         = {{0094-8276}},
  keywords     = {{hotspot-ridge interaction; International Ocean Discovery Program (IODP) Expedition 391; magnetic anomalies; oceanic plateau; Valdivia Bank; Walvis Ridge}},
  language     = {{eng}},
  number       = {{13}},
  publisher    = {{American Geophysical Union (AGU)}},
  series       = {{Geophysical Research Letters}},
  title        = {{Nature and Origin of Magnetic Lineations Within Valdivia Bank : Ocean Plateau Formation by Complex Seafloor Spreading}},
  url          = {{http://dx.doi.org/10.1029/2023GL103415}},
  doi          = {{10.1029/2023GL103415}},
  volume       = {{50}},
  year         = {{2023}},
}