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dc.contributor.authorSmith, Deborah K.  Concept link
dc.contributor.authorSchouten, Hans A.  Concept link
dc.contributor.authorZhu, Wenlu  Concept link
dc.contributor.authorMontesi, Laurent G. J.  Concept link
dc.contributor.authorCann, Johnson R.  Concept link
dc.date.accessioned2011-12-14T17:17:27Z
dc.date.available2014-10-22T08:57:24Z
dc.date.issued2011-11-08
dc.identifier.citationGeochemistry Geophysics Geosystems 12 (2011): Q11003en_US
dc.identifier.urihttps://hdl.handle.net/1912/4937
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 Geochemistry Geophysics Geosystems 12 (2011): Q11003, doi:10.1029/2011GC003689.en_US
dc.description.abstractThe Galapagos triple junction is not a simple ridge-ridge-ridge (RRR) triple junction. The Cocos-Nazca Rift (C-N Rift) tip does not meet the East Pacific Rise (EPR). Instead, two secondary rifts form the link: Incipient Rift at 2°40′N and Dietz Deep volcanic ridge, the southern boundary of the Galapagos microplate (GMP), at 1°10′N. Recently collected bathymetry data are used to investigate the regional tectonics prior to the establishment of the GMP (∼1.5 Ma). South of C-N Rift a band of northeast-trending cracks cuts EPR-generated abyssal hills. It is a mirror image of a band of cracks previously identified north of C-N Rift on the same age crust. In both areas, the western ends of the cracks terminate against intact abyssal hills suggesting that each crack initiated at the EPR spreading center and cut eastward into pre-existing topography. Each crack formed a short-lived triple junction until it was abandoned and a new crack and triple junction initiated nearby. Between 2.5 and 1.5 Ma, the pattern of cracking is remarkably symmetric about C-N Rift providing support for a crack interaction model in which crack initiation at the EPR axis is controlled by stresses associated with the tip of the westward-propagating C-N Rift. The model also shows that offsets of the EPR axis may explain times when cracking is not symmetric. South of C-N Rift, cracks are observed on seafloor as old as 10.5 Ma suggesting that this triple junction has not been a simple RRR triple junction during that time.en_US
dc.description.sponsorshipHS was supported by the U.S. National Science Foundation (NSF) grant OCE‐0751831, DS by NSF grant OCE‐1028537, WZ by NSF grant EAR‐1056317, and LM by NSF grant EAR‐0911151.en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/2011GC003689
dc.subjectEast Pacific Riseen_US
dc.subjectGalapagos triple junctionen_US
dc.subjectCrack propagationen_US
dc.subjectTriple junctionen_US
dc.titleDistributed deformation ahead of the Cocos-Nazca Rift at the Galapagos triple junctionen_US
dc.typeArticleen_US
dc.description.embargo2012-05-08
dc.identifier.doi10.1029/2011GC003689


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