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dc.contributor.authorSmith, Deborah K.  Concept link
dc.contributor.authorSchouten, Hans A.  Concept link
dc.contributor.authorParnell-Turner, Ross  Concept link
dc.contributor.authorKlein, Emily M.  Concept link
dc.contributor.authorCann, Johnson R.  Concept link
dc.contributor.authorDunham, Charles  Concept link
dc.contributor.authorAlodia, Gabriella  Concept link
dc.contributor.authorBlasco, Iker  Concept link
dc.contributor.authorWernette, Benjamin  Concept link
dc.contributor.authorZawadzki, Dominik  Concept link
dc.contributor.authorLatypova, Elvira  Concept link
dc.contributor.authorAfshar, Sara  Concept link
dc.contributor.authorCurry, Scott  Concept link
dc.date.accessioned2020-07-30T20:56:29Z
dc.date.issued2020-05-11
dc.identifier.citationSmith, D. K., Schouten, H., Parnell-Turner, R., Klein, E. M., Cann, J., Dunham, C., Alodia, G., Blasco, I., Wernette, B., Zawadzki, D., Latypova, E., Afshar, S., & Curry, S. (2020). The evolution of seafloor spreading behind the tip of the westward propagating Cocos-Nazca spreading center. Geochemistry Geophysics Geosystems, 21(6), e2020GC008957.en_US
dc.identifier.urihttps://hdl.handle.net/1912/26034
dc.descriptionAuthor Posting. © American Geophysical Union, 2020. 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 21(6), (2020): e2020GC008957, doi:10.1029/2020GC008957.en_US
dc.description.abstractAt the Galapagos triple junction in the equatorial Pacific Ocean, the Cocos‐Nazca spreading center does not meet the East Pacific Rise (EPR) but, instead, rifts into 0.4 Myr‐old lithosphere on the EPR flank. Westward propagation of Cocos‐Nazca spreading forms the V‐shaped Galapagos gore. Since ~1.4 Ma, opening at the active gore tip has been within the Cocos‐Galapagos microplate spreading regime. In this paper, bathymetry, magnetic, and gravity data collected over the first 400 km east of the gore tip are used to examine rifting of young lithosphere and transition to magmatic spreading segments. From inception, the axis shows structural segmentation consisting of rifted basins whose bounding faults eventually mark the gore edges. Rifting progresses to magmatic spreading over the first three segments (s1–s3), which open between Cocos‐Galapagos microplate at the presently slow rates of ~19–29 mm/year. Segments s4–s9 originated in the faster‐spreading (~48 mm/year) Cocos‐Nazca regime, and well‐defined magnetic anomalies and abyssal hill fabric close to the gore edges show the transition to full magmatic spreading was more rapid than at present time. Magnetic lineations show a 20% increase in the Cocos‐Nazca spreading rate after 1.1 Ma. The near‐axis Mantle Bouguer gravity anomaly decreases eastward and becomes more circular, suggesting mantle upwelling, increasing temperatures, and perhaps progression to a developed melt supply beneath segments. Westward propagation of individual Cocos‐Nazca segments is common with rates ranging between 12 and 54 mm/year. Segment lengths and lateral offsets between segments increase, in general, with distance from the tip of the gore.en_US
dc.description.sponsorshipE. M. and H. S. are grateful to the National Science Foundation for funding this work and to InterRidge and the University of Leeds for providing support for a number of the international students and scholars who were able to participate on the cruise. We are also grateful for the extraordinary work of the Captain and crew of R/V Sally Ride , whose efficiency and good cheer made the cruise such a success. We thank M. Ligi and two anonymous reviewers for their comments which greatly improved the manuscript. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.en_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/2020GC008957
dc.subjectGalapagos triple junctionen_US
dc.subjectmid‐ocean ridgesen_US
dc.subjectseafloor spreadingen_US
dc.subjectGalapagos microplateen_US
dc.subjectplate boundariesen_US
dc.titleThe evolution of seafloor spreading behind the tip of the westward propagating Cocos-Nazca spreading centeren_US
dc.typeArticleen_US
dc.description.embargo2020-11-11en_US
dc.identifier.doi10.1029/2020GC008957
dc.embargo.liftdate2020-11-11


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