2010/12/01 by Matthew G. Jackson, Stanley R. Hart, J. G. Konter +5 · 101 citations
Earth and Planetary Sciences · #Geological and Geochemical Analysis #earthquake and tectonic studies #High-pressure geophysics and materials #Samoan #Geology #Mantle plume #Mantle (geology) #Hotspot (geology) #Lithosphere #Seamount #Volcano #Geochemistry #Seismology #Tectonics
paper · pdf · doi:10.1029/2010gc003232
published in Geochemistry Geophysics Geosystems 11(12) (Wiley)
openalex publication_date 2010/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We report new geochemical data for submarine lavas from the Samoan region that greatly enhance the geochemical data set for volcanoes from the hot spot. Additionally, two volcanoes dredged in the northern Lau Basin, Futuna Island and Manatu seamount, are young (<5 Ma), appear to be genetically related, and may have been generated by melting a component of Samoan mantle that has been advected into the region. We also find evidence for three seamounts and one atoll along the Samoan hot spot track that are not geochemically related to Samoa. We use a plate motion model to show that three non‐Samoan hot spots, currently active in the Cook‐Austral Islands, provided volcanism to the Pacific Plate now in the Samoan region approximately 10–40 Ma. The four interloping volcanoes in the Samoan region exhibit geochemical affinities with the three hot spots. All three hot spots would have left a depleted, viscous, refractory keel that is coupled to the base of the Pacific lithosphere that has been “rafted” to the Samoan region. Therefore, the new data also have implications for the origin of the Samoan hot spot as its origin has been suggested to be a result of either a deep‐seated mantle plume or a consequence of lithospheric cracking. Without major modification of the current “propagating lithospheric cracks” model, it is not clear how such cracks could yield melts from the refractory keel present under the Samoan lithosphere. Instead, a region of buoyantly upwelling mantle, or plume, is suggested to generate the shield stage volcanism in the Samoan region.