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dc.contributor.authorWorkman, Rhea K.  Concept link
dc.contributor.authorHart, Stanley R.  Concept link
dc.contributor.authorJackson, Matthew G.  Concept link
dc.contributor.authorRegelous, Marcel  Concept link
dc.contributor.authorFarley, Kenneth A.  Concept link
dc.contributor.authorBlusztajn, Jerzy S.  Concept link
dc.contributor.authorKurz, Mark D.  Concept link
dc.contributor.authorStaudigel, Hubert  Concept link
dc.date.accessioned2006-01-26T16:12:23Z
dc.date.available2006-01-26T16:12:23Z
dc.date.issued2004-04-27
dc.identifier.citationGeochemistry Geophysics Geosystems 5 (2005): Q04008en
dc.identifier.urihttps://hdl.handle.net/1912/462
dc.descriptionAuthor Posting. © American Geophysical Union, 2005. 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 5 (2005): Q04008, doi:10.1029/2003GC000623.
dc.description.abstractAn in-depth Sr-Nd-Pb-He-Os isotope and trace element study of the EMII-defining Samoan hot spot lavas leads to a new working hypothesis for the origin of this high 87Sr/86Sr mantle end-member. Systematics of the Samoan fingerprint include (1) increasing 206Pb/204Pb with time - from 18.6 at the older, western volcanoes to 19.4 at the present-day hot spot center, Vailulu'u Seamount, (2) en-echelon arrays in 206Pb/204Pb – 208Pb/204Pb space which correspond to the two topographic lineaments of the 375 km long volcanic chain – this is much like the Kea and Loa Trends in Hawai'i, (3) the highest 87Sr/86Sr (0.7089) of all oceanic basalts, (4) an asymptotic decrease in 3He/4He from 24 RA [Farley et al., 1992] to the MORB value of 8 RA with increasing 87Sr/86Sr, and (5) mixing among four components which are best described as the “enriched mantle”, the depleted FOZO mantle, the (even more depleted) MORB Mantle, and a mild HIMU (high 238U/204Pb) mantle component. A theoretical, “pure” EMII lava composition has been calculated and indicates an extremely smooth trace element pattern of this end-member mantle reservoir. The standard recycling model (of ocean crust/sediment) fails as an explanation for producing Samoan EM2, due to these smooth spidergrams for EM2 lavas, low 187Os/188Os ratios and high 3He/4He (>8 RA). Instead, the origin of EM2 has been modeled with the ancient formation of metasomatised oceanic lithosphere, followed by storage in the deep mantle and return to the surface in the Samoan plume.en
dc.description.sponsorshipWe acknowledge NSF support, through grant OCE-9819038 (SRH and HS), and EAR-0125917 (SRH).en
dc.format.extent2075846 bytes
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen
dc.publisherAmerican Geophysical Unionen
dc.relation.urihttps://doi.org/10.1029/2003GC000623
dc.titleRecycled metasomatized lithosphere as the origin of the Enriched Mantle II (EM2) end-member : evidence from the Samoan Volcanic Chainen
dc.typeArticleen
dc.identifier.doi10.1029/2003GC000623


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