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dc.contributor.authorGeist, Dennis J.  Concept link
dc.contributor.authorDiefenbach, Bridget A.  Concept link
dc.contributor.authorFornari, Daniel J.  Concept link
dc.contributor.authorKurz, Mark D.  Concept link
dc.contributor.authorHarpp, Karen S.  Concept link
dc.contributor.authorBlusztajn, Jerzy S.  Concept link
dc.date.accessioned2010-04-20T15:51:47Z
dc.date.available2010-04-20T15:51:47Z
dc.date.issued2008-03-19
dc.identifier.citationGeochemistry Geophysics Geosystems 9 (2008): Q03015en_US
dc.identifier.urihttps://hdl.handle.net/1912/3268
dc.descriptionAuthor Posting. © American Geophysical Union, 2008. 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 9 (2008): Q03015, doi:10.1029/2007GC001795.en_US
dc.description.abstractNew multibeam bathymetric and side-scan sonar data from the southwestern edge of the Galápagos platform reveal the presence of ∼60 large, stepped submarine terraces between depths of 800 m and 3500 m. These terraces are unique features, as none are known from any other archipelago that share this geomorphic form or size. The terraces slope seaward at <2° and are surrounded by escarpments that average ∼300 m in height with average slopes of 24°. The stepped morphology, fine-scale features, and sinuous planform continuity of terrace edges indicate that each terrace results from a sequence of major submarine volcanic eruptions, similar in extent to young deep-water (>3000 m) lava flow fields west of Fernandina and Isabela Islands. The terraces are formed of thick sequences of lava flows that coalesce to form the foundation of the Galápagos platform, on which the subaerial central volcanoes are built. The compositions of basalts dredged from the submarine terraces indicate that most lavas are chemically similar to subaerial lavas erupted from Sierra Negra volcano on southern Isabela Island. There are no regular major element, trace element, or isotopic variations in the submarine lavas as a function of depth, relative stratigraphic position, or geographic location along the southwest margin of the platform. We hypothesize that magma supply at the western edge of the Galápagos hot spot, which is influenced by both plume and mid-ocean ridge magmatic processes, leads to episodic eruption of large lava flows. These large lava flows coalesce to form the archipelagic apron upon which the island volcanoes are built.en_US
dc.description.sponsorshipThis work was supported by the National Science Foundation grants OCE0002818 and EAR0207605 (D.G.), OCE0002461 (D.J.F. and M.K.), OCE05-25864 (M.K.), and EAR0207425 (K.H.).en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/2007GC001795
dc.subjectSubmarine volcanismen_US
dc.titleConstruction of the Galapagos platform by large submarine volcanic terracesen_US
dc.typeArticleen_US
dc.identifier.doi10.1029/2007GC001795


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