Geochemical characterization of endmember mantle components

dc.contributor.author Workman, Rhea K.
dc.coverage.spatial Vailulu'u
dc.coverage.spatial Muli
dc.coverage.spatial Malumalu
dc.coverage.spatial Ta'u
dc.coverage.spatial Savai'i
dc.coverage.spatial Upolu
dc.date.accessioned 2007-05-09T14:21:45Z
dc.date.available 2007-05-09T14:21:45Z
dc.date.issued 2005-06
dc.description Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2005 en
dc.description.abstract This thesis uses trace elements and radiogenic isotope tracers to define elemental abundances in reservoirs of the Earth's mantle, including EM2 (the Enriched Mantle 2), as seen in the Samoan hotspot track, and DMM (the depleted upper mantle), which is sampled at mid-ocean ridges. Together these components comprise up to -50% of the total mantle mass. Much of the mantle's chemical heterogeneities are suspected to originate by either the removal of mass from the mantle (in the case of DMM) or the addition of mass to the mantle through subduction zones (in the case of EM2). We show that DMM represents mantle that 1) has been previously depleted by 2-3% melt removal, 2) mass-balances well with the continental crust, 3) has only 15% of the radiogenic heat production in primitive upper mantle and 4) can generate present-day ocean crust by 6% aggregated fractional melting. EM2 is classically interpreted as mantle material enriched in trace elements through the ancient, subduction-zone recycling of terrigenous sediments; here we show this model is unlikely and provide two other working hypotheses. The first is recycling of melt-impregnated oceanic lithosphere; the second is recycling of a mantle wedge impregnated with melt from a subducting oceanic plate. en
dc.description.sponsorship Very generous financial support for this thesis has been provided by WHO17s Academic Programs Office, NSF grants 8 1903800,80489100 and 82591700 to Stan Hart and the Cole Ocean Ventures Fund. en
dc.format.mimetype application/pdf
dc.identifier.citation Workman, R. K. (2005). Geochemical characterization of endmember mantle components [Doctoral thesis, Massachusetts Institute of Technology and Woods Hole Oceanographic Institution]. Woods Hole Open Access Server. https://doi.org/10.1575/1912/1622
dc.identifier.doi 10.1575/1912/1622
dc.identifier.uri https://hdl.handle.net/1912/1622
dc.language.iso en_US en
dc.publisher Massachusetts Institute of Technology and Woods Hole Oceanographic Institution en
dc.relation.ispartofseries WHOI Theses en
dc.subject Chemical elements en_US
dc.subject Mantle en_US
dc.subject Melville (Ship) Cruise AVON 2 en_US
dc.subject Melville (Ship) Cruise AVON 3 en_US
dc.title Geochemical characterization of endmember mantle components en
dc.type Thesis en
dspace.entity.type Publication
relation.isAuthorOfPublication 2fee66ac-0cc1-4926-982e-5b8db5d7f385
relation.isAuthorOfPublication.latestForDiscovery 2fee66ac-0cc1-4926-982e-5b8db5d7f385
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