"Petit spot" rejuvenated volcanism superimposed on plume-derived Samoan shield volcanoes: Evidence from a 645-m drill core from Tutuila Island, American Samoa
Reinhard, Andrew A.
Jackson, Matthew G.
Blusztajn, Jerzy S.
Koppers, Anthony A. P.
Simms, Alexander R.
Konter, Jasper G.
MetadataShow full item record
In 2015 a geothermal exploration well was drilled on the island of Tutuila, American Samoa. The sample suite from the drill core provides 645 m of volcanic stratigraphy from a Samoan volcano, spanning 1.45 million years of volcanic history. In the Tutuila drill core, shield lavas with an EM2 (enriched mantle 2) signature are observed at depth, spanning 1.46 to 1.44 Ma. These are overlain by younger (1.35 to 1.17 Ma) shield lavas with a primordial “common” (focus zone) component interlayered with lavas that sample a depleted mantle component. Following ~1.15 Myr of volcanic quiescence, rejuvenated volcanism initiated at 24.3 ka and samples an EM1 (enriched mantle 1) component. The timing of the initiation of rejuvenated volcanism on Tutuila suggests that rejuvenated volcanism may be tectonically driven, as Samoan hotspot volcanoes approach the northern terminus of the Tonga Trench. This is consistent with a model where the timing of rejuvenated volcanism at Tutuila and at other Samoan volcanoes relates to their distance from the Tonga Trench. Notably, the Samoan rejuvenated lavas have EM1 isotopic compositions distinct from shield lavas that are geochemically similar to “petit spot” lavas erupted outboard of the Japan Trench and late stage lavas erupted at Christmas Island located outboard of the Sunda Trench. Therefore, like the Samoan rejuvenated lavas, petit spot volcanism in general appears to be related to tectonic uplift outboard of subduction zones, and existing geochemical data suggest that petit spots share similar EM1 isotopic signatures.
Author Posting. © American Geophysical Union, 2019. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 20(3), (2019): 1485-1507, doi:10.1029/2018GC007985.
Suggested CitationReinhard, A. A., Jackson, M. G., Blusztajn, J., Koppers, A. A. P., Simms, A. R., & Konter, J. G. (2019). "Petit spot" rejuvenated volcanism superimposed on plume-derived Samoan shield volcanoes: Evidence from a 645-m drill core from Tutuila Island, American Samoa. Geochemistry Geophysics Geosystems, 20(3), 1485-1507.
Showing items related by title, author, creator and subject.
Seafloor seismic monitoring of an active submarine volcano : local seismicity at Vailulu'u Seamount, Samoa Konter, Jasper G.; Staudigel, Hubert; Hart, Stanley R.; Shearer, Peter M. (American Geophysical Union, 2004-06-26)We deployed five ocean bottom hydrophones (OBHs) for a 1-year seismic monitoring study of Vailulu'u Seamount, the youngest and easternmost volcano in the Samoan Archipelago. Four instruments were placed on the summit crater ...
238U-Th-230-Ra-226-Pb-210-Po-210, Th-232-Ra-228, and U-235-Pa-231 constraints on the ages and petrogenesis of Vailulu'u and Malumalu Lavas, Samoa Sims, Kenneth W. W.; Hart, Stanley R.; Reagan, Mark K.; Blusztajn, Jerzy S.; Staudigel, Hubert; Sohn, Robert A.; Layne, Graham D.; Ball, Lary A.; Andrews, J. E. (American Geophysical Union, 2008-04-01)We report 238U-230Th-226Ra-210Pb-210Po, 232Th-228Ra and 235U-231Pa measurements for a suite of 14 geologically and geochemically well-characterized basaltic samples from the Samoan volcanoes Vailulu'u, Malumalu, and Savai'i. ...
Hudak, Michael R.; Bindeman, Ilya N.; Loewen, Matthew W.; Giachetti, Thomas (American Geophysical Union, 2021-11-15)Magma-water interaction can dramatically influence the explosivity of volcanic eruptions. However, syn- and post-eruptive diffusion of external (non-magmatic) water into volcanic glass remains poorly constrained and may ...