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dc.contributor.authorDunn, Robert A.  Concept link
dc.contributor.authorLekic, Vedran  Concept link
dc.contributor.authorDetrick, Robert S.  Concept link
dc.contributor.authorToomey, Douglas R.  Concept link
dc.date.accessioned2010-05-27T13:08:26Z
dc.date.available2010-05-27T13:08:26Z
dc.date.issued2005-09-09
dc.identifier.citationJournal of Geophysical Research 110 (2005): B09101en_US
dc.identifier.urihttps://hdl.handle.net/1912/3540
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 Journal of Geophysical Research 110 (2005): B09101, doi:10.1029/2004JB003473.en_US
dc.description.abstractWe gathered seismic refraction and wide-angle reflection data from several active source experiments that occurred along the Mid-Atlantic Ridge near 35°N and constructed three-dimensional anisotropic tomographic images of the crust and upper mantle velocity structure and crustal thickness. The tomographic images reveal anomalously thick crust (8–9 km) and a low-velocity “bull's-eye”, from 4 to 10 km depth, beneath the center of the ridge segment. The velocity anomaly is indicative of high temperatures and a small amount of melt (up to 5%) and likely represents the current magma plumbing system for melts ascending from the mantle. In addition, at the segment center, seismic anisotropy in the lower crust indicates that the crust is composed of partially molten dikes that are surrounded by regions of hot rock with little or no melt fraction. Our results indicate that mantle melts are focused at mantle depths to the segment center and that melt is delivered to the crust via dikes in the lower crust. Our results also indicate that the segment ends are colder, receive a reduced magma supply, and undergo significantly greater tectonic stretching than the segment center.en_US
dc.description.sponsorshipThis research was supported by U.S. National Science Foundation grants OCE-0203228 and OCE-0136793; support for V. Lekic was provided by the IRIS undergraduate internship program.en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/2004JB003473
dc.subjectMid-Atlantic Ridgeen_US
dc.subjectSeismic tomographyen_US
dc.subjectSeismic anisotropyen_US
dc.titleThree-dimensional seismic structure of the Mid-Atlantic Ridge (35°N) : evidence for focused melt supply and lower crustal dike injectionen_US
dc.typeArticleen_US
dc.identifier.doi10.1029/2004JB003473


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