Geophysical Research Letters (Jul 2023)
Nature and Origin of Magnetic Lineations Within Valdivia Bank: Ocean Plateau Formation by Complex Seafloor Spreading
- S. Thoram,
- W. W. Sager,
- K. Gaastra,
- S. M. Tikoo,
- C. Carvallo,
- A. Avery,
- Arianna V. Del Gaudio,
- Y. Huang,
- K. Hoernle,
- T. W. Höfig,
- R. Bhutani,
- D. M. Buchs,
- C. Class,
- Y. Dai,
- G. Dalla Valle,
- S. Fielding,
- S. Han,
- D. E. Heaton,
- S. Homrighausen,
- Y. Kubota,
- C.‐F. Li,
- W. R. Nelson,
- E. Petrou,
- K. E. Potter,
- S. Pujatti,
- J. Scholpp,
- J. W. Shervais,
- M. Tshiningayamwe,
- X. J. Wang,
- M. Widdowson
Affiliations
- S. Thoram
- Department of Earth and Atmospheric Sciences University of Houston TX Houston USA
- W. W. Sager
- Department of Earth and Atmospheric Sciences University of Houston TX Houston USA
- K. Gaastra
- Department of Earth Environmental and Planetary Sciences Rice University TX Houston USA
- S. M. Tikoo
- Department of Geophysics Stanford University CA Stanford USA
- C. Carvallo
- Sorbonne Université MNHN CNRS UMR Institut de Minéralogie de Physique des Matériaux et de Cosmochimie Paris France
- A. Avery
- School of Geosciences University of South Florida FL Tampa USA
- Arianna V. Del Gaudio
- Institute of Earth Sciences University of Graz Graz Austria
- Y. Huang
- Key Laboratory of Exploration Technologies for Oil and Gas Resources (Yangtze University) Ministry of Education Wuhan China
- K. Hoernle
- GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany
- T. W. Höfig
- International Ocean Discovery Program Texas A&M University TX College Station USA
- R. Bhutani
- Department of Earth Sciences Pondicherry University Puducherry India
- D. M. Buchs
- School of Earth and Ocean Sciences Cardiff University Cardiff UK
- C. Class
- Lamont‐Doherty Earth Observatory Columbia University NY Palisades USA
- Y. Dai
- Department of Geology Lund University Lund Sweden
- G. Dalla Valle
- Institute for Marine Sciences National Research Council Bologna Italy
- S. Fielding
- Geology Department University of Namibia Windhoek Namibia
- S. Han
- School of Environmental Science and Technology Gwangju Institute of Science and Technology Gwangju South Korea
- D. E. Heaton
- CEOAS Oregon State University OR Corvallis USA
- S. Homrighausen
- GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany
- Y. Kubota
- Department of Geosciences Penn State University PA State College USA
- C.‐F. Li
- Ocean College Zhejiang University Zhoushan China
- W. R. Nelson
- Department of Physics, Astronomy & Geosciences Towson University MD Towson USA
- E. Petrou
- Department of Earth Sciences University of Oxford Oxford UK
- K. E. Potter
- Department of Geology Utah State University UT Logan USA
- S. Pujatti
- Department of Geoscience University of Calgary AB Calgary Canada
- J. Scholpp
- Department of Earth and Planetary Sciences University of Tennessee TN Knoxville USA
- J. W. Shervais
- Department of Geology Utah State University UT Logan USA
- M. Tshiningayamwe
- Geology Department University of Namibia Keetmanshoop Namibia
- X. J. Wang
- Department of Geology Northwest University Xi'an China
- M. Widdowson
- School of Environmental Sciences University of Hull Hull UK
- DOI
- https://doi.org/10.1029/2023GL103415
- Journal volume & issue
-
Vol. 50,
no. 13
pp. n/a – n/a
Abstract
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 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.
Keywords
- Valdivia Bank
- Walvis Ridge
- oceanic plateau
- magnetic anomalies
- International Ocean Discovery Program (IODP) Expedition 391
- hotspot‐ridge interaction
