Insights into the petrogenesis of an intraplate volcanic province: Sr-Nd-Pb-Hf isotope geochemistry of the Bathymetrists Seamount Province, eastern equatorial Atlantic
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ArticleAuthors
Long, Xiaojun
Van der Zwan, Froukje M.

Geldmacher, Jörg
Hoernle, Kaj

Hauff, Folkmar
Garbe-Schönberg, C.-Dieter
Augustin, Nico
KAUST Department
King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.Date
2020-06Embargo End Date
2022-05-04Submitted Date
2019-11-27Permanent link to this record
http://hdl.handle.net/10754/666861
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Show full item recordAbstract
Unlike the well-studied narrow hotspot tracks, the origin of broadly distributed seamount provinces remains a topic of conjecture. Here we present major and trace element and Sr-Nd-Hf-Pb double spike isotope data of a comprehensive sample suite from the Bathymetrists Seamount Province, a broad belt of submarine volcanoes in the eastern equatorial Atlantic, and from the neighboring Cape Verde Ridge, a topographic high on the shoulder of a local fracture zone. The major and trace element results are consistent with the Bathymetrists Seamount Province having formed in an intraplate setting. The isotopic composition of the seamount lavas resemble a HIMU-like signature (206Pb/204Pbin = 19.23–20.35) similar to the nearby St. Helena hotspot composition. Based on plate tectonic reconstructions, a formation of the Bathymetrists Seamount Province by the postulated Sierra Leone plume, believed to be responsible for the geochemical anomaly at the mid ocean ridge at 1.7°N and the nearby St. Peter and Pauls rocks, is not supported. An alternative model that the Bathymetrists Seamount Province was created by edge driven convection in the upper mantle along the boundary of the neighboring Sierra Leone Rise plateau is also not supported by the available data. Plate tectonic reconstructions, however, are consistent with a hotspot origin for the Bathymetrists Seamount Province, as is the presence of a seismic tomographic anomaly at the southwest end of the seamount belt.Citation
Long, X., van der Zwan, F. M., Geldmacher, J., Hoernle, K., Hauff, F., Garbe-Schönberg, C.-D., & Augustin, N. (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. doi:10.1016/j.chemgeo.2020.119599Sponsors
We thank Captain Ralf Schmidt and his crew for their support during the MSM70 cruise, the Leitstelle Deutsche Forschungschiffe for the organization of the cruise and the MSM70 scientific party for their help in obtaining the samples. In addition, we are very grateful to Silke Hauff, Karin Junge, Marcus Gutjahr (all GEOMAR) and Ulrike Westernströer (Kiel University) for their help with the sample analysis. X.L. was funded by the China Scholarship Council (CSC, funding reference number: [2015]0672). Analytical work was funded by the DFG (MSM70 initial postcruise funding) and GEOMAR. We thank Catherine Chauvel for editorial handling of this manuscript and Dennis Geist, Tyrone Rooney and one anonymous reviewer for providing constructive reviews.Publisher
Elsevier BVJournal
Chemical GeologyAdditional Links
https://linkinghub.elsevier.com/retrieve/pii/S0009254120301388ae974a485f413a2113503eed53cd6c53
10.1016/j.chemgeo.2020.119599