Show simple item record

dc.contributor.authorAnderson, Molly  Concept link
dc.contributor.authorWanless, V. Dorsey  Concept link
dc.contributor.authorSchwartz, Darin M.  Concept link
dc.contributor.authorMcCully, Emma  Concept link
dc.contributor.authorFornari, Daniel J.  Concept link
dc.contributor.authorJones, Meghan R.  Concept link
dc.contributor.authorSoule, Samuel A.  Concept link
dc.date.accessioned2018-12-06T17:38:04Z
dc.date.issued2018-10-25
dc.identifier.citationGeochemistry, Geophysics, Geosystems 19 (2018): 3945–3961en_US
dc.identifier.urihttps://hdl.handle.net/1912/10771
dc.descriptionAuthor Posting. © American Geophysical Union, 2018. 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 19 (2018): 3945–3961, doi:10.1029/2018GC007632.en_US
dc.description.abstractTo investigate the initial phases of magmatism at the leading edge of the upwelling mantle plume, we mapped, photographed, and collected samples from two long, deep‐water lava flows located at the western base of the Galápagos Platform using the remotely operated vehicle Hercules. Lavas were recovered from four areas on the seafloor west of Fernandina volcano, including the western flow fronts of two deep‐water flows, heavily sedimented terrain between the two flows, and the eastern, shallower end of one flow. The sediment cover and morphologies are distinct between the western flow fronts and the eastern region based on seafloor imagery, suggesting that the long lava flows are not a single eruptive unit. Major and trace element concentrations reveal both tholeiitic and alkalic compositions and support the interpretation that multiple eruptive units comprise the deep‐water flows. Alkalic lavas have higher [La/Sm]N ratios (2.05–2.12) and total alkali contents (5.18–5.40) compared to tholeiitic lavas, which have [La/Sm]N ratios ranging from 1.64 to 1.68 and total alkali contents ranging from 3.07 to 4.08 wt%. Radiogenic isotope ratios are relatively homogeneous, suggesting a similar mantle source. We use petrologic models to assess three alternative mechanisms for the formation of the alkalic magmas: (1) high‐pressure crystallization of clinopyroxene, (2) mixing of high silica and mafic magmas, and (3) variable extents of melting of the same mantle source. Our modeling indicates that the alkalic samples form from lower extents of melting compared to the tholeiitic lavas and suggests that the deep‐water alkalic lavas are analogous to the initial, preshield building phase observed south of Hawaii and at the base of Loihi Seamount.en_US
dc.description.sponsorshipDalio Explorer Fund; National Science Foundation (NSF) Grant Number: OCE‐1634952en_US
dc.language.isoen_USen_US
dc.publisherJohn Wiley & Sonsen_US
dc.relation.urihttps://doi.org/10.1029/2018GC007632
dc.subjectSubmarine volcanismen_US
dc.subjectGalápagosen_US
dc.subjectAlkalic magmatismen_US
dc.subjectMantle plumeen_US
dc.subjectMantle meltingen_US
dc.subjectRadiogenic isotopesen_US
dc.titleSubmarine deep‐water lava flows at the base of the western Galápagos Platformen_US
dc.typeArticleen_US
dc.description.embargo2019-04-25en_US
dc.identifier.doi10.1029/2018GC007632
dc.embargo.liftdate2019-04-25


Files in this item

Thumbnail
Thumbnail
Thumbnail
Thumbnail
Thumbnail
Thumbnail

This item appears in the following Collection(s)

Show simple item record