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dc.contributor.authorMontesi, Laurent G. J.  Concept link
dc.contributor.authorBehn, Mark D.  Concept link
dc.contributor.authorHebert, Laura B.  Concept link
dc.contributor.authorLin, Jian  Concept link
dc.contributor.authorBarry, Jennifer L.  Concept link
dc.date.accessioned2011-11-08T15:59:19Z
dc.date.available2012-04-04T08:32:59Z
dc.date.issued2011-10-04
dc.identifier.citationJournal of Geophysical Research 116 (2011): B10102en_US
dc.identifier.urihttps://hdl.handle.net/1912/4881
dc.descriptionAuthor Posting. © American Geophysical Union, 2011. 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 116 (2011): B10102, doi:10.1029/2011JB008259.en_US
dc.description.abstractCrustal thickness variations at the ultraslow spreading 10–16°E region of the Southwest Indian Ridge are used to constrain melt migration processes. In the study area, ridge morphology correlates with the obliquity of the ridge axis with respect to the spreading direction. A long oblique “supersegment”, nearly devoid of magmatism, is flanked at either end by robust magmatic centers (Joseph Mayes Seamount and Narrowgate segment) of much lesser obliquity. Plate-driven mantle flow and temperature structure are calculated in 3-D based on the observed ridge segmentation. Melt extraction is assumed to occur in three steps: (1) vertical migration out of the melting region, (2) focusing along an inclined permeability barrier, and (3) extraction when the melt enters a region shallower than ∼35 km within 5 km of the ridge axis. No crust is predicted in our model along the oblique supersegment. The formation of Joseph Mayes Seamount is consistent with an on-axis melt anomaly induced by the local orthogonal spreading. The crustal thickness anomaly at Narrowgate results from melt extracted at a tectonic damage zone as it travels along the axis toward regions of lesser obliquity. Orthogonal spreading enhances the Narrowgate crustal thickness anomaly but is not necessary for it. The lack of a residual mantle Bouguer gravity high along the oblique supersegment can be explained by deep serpentization of the upper mantle permissible by the thermal structure of this ridge segment. Buoyancy-driven upwelling and/or mantle heterogeneities are not required to explain the extreme focusing of melt in the study area.en_US
dc.description.sponsorshipThis work was supported by grants OCE‐ 0623188 and OCE‐0937277 from the National Science Foundation.en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/2011JB008259
dc.subjectMid-ocean ridgesen_US
dc.subjectSouthwest Indian Ridgeen_US
dc.subjectCrustal accretionen_US
dc.subjectMelt migrationen_US
dc.subjectSerpentinizationen_US
dc.titleControls on melt migration and extraction at the ultraslow Southwest Indian Ridge 10°–16°Een_US
dc.typeArticleen_US
dc.identifier.doi10.1029/2011JB008259


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