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Non-hotspot volcano chains produced by migration of shear-driven upwelling toward the East Pacific Rise

2013; Geological Society of America; Volume: 41; Issue: 4 Linguagem: Inglês

10.1130/g33804.1

1943-2682

Maxim Ballmer, Clinton P. Conrad, Eugene I. Smith, Nicholas Harmon,

Geology and Paleoclimatology Research

Research Article| April 01, 2013 Non-hotspot volcano chains produced by migration of shear-driven upwelling toward the East Pacific Rise Maxim D. Ballmer; Maxim D. Ballmer 1Department of Geology and Geophysics, School of Ocean and Earth Sciences and Technology, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA Search for other works by this author on: GSW Google Scholar Clinton P. Conrad; Clinton P. Conrad 1Department of Geology and Geophysics, School of Ocean and Earth Sciences and Technology, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA Search for other works by this author on: GSW Google Scholar Eugene I. Smith; Eugene I. Smith 2Department of Geoscience, University of Nevada Las Vegas, Las Vegas, Nevada 89154, USA Search for other works by this author on: GSW Google Scholar Nicholas Harmon Nicholas Harmon 3National Oceanography Centre Southampton, Ocean and Earth Science, University of Southampton, Southampton SH14 3ZH, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Maxim D. Ballmer 1Department of Geology and Geophysics, School of Ocean and Earth Sciences and Technology, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA Clinton P. Conrad 1Department of Geology and Geophysics, School of Ocean and Earth Sciences and Technology, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA Eugene I. Smith 2Department of Geoscience, University of Nevada Las Vegas, Las Vegas, Nevada 89154, USA Nicholas Harmon 3National Oceanography Centre Southampton, Ocean and Earth Science, University of Southampton, Southampton SH14 3ZH, UK Publisher: Geological Society of America Received: 29 Jun 2012 Revision Received: 08 Nov 2012 Accepted: 24 Nov 2012 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2013 Geological Society of America Geology (2013) 41 (4): 479–482. https://doi.org/10.1130/G33804.1 Article history Received: 29 Jun 2012 Revision Received: 08 Nov 2012 Accepted: 24 Nov 2012 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Maxim D. Ballmer, Clinton P. Conrad, Eugene I. Smith, Nicholas Harmon; Non-hotspot volcano chains produced by migration of shear-driven upwelling toward the East Pacific Rise. Geology 2013;; 41 (4): 479–482. doi: https://doi.org/10.1130/G33804.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract While most oceanic volcanism is associated with the passive rise of hot mantle beneath the spreading axes of mid-ocean ridges (MOR), volcanism occurring off-axis reflects intraplate upper-mantle dynamics and composition, yet is poorly understood. Off the south East Pacific Rise (SEPR), volcanism along the Pukapuka, Hotu-Matua, and Sojourn ridges has been attributed to various mechanisms, but none can reconcile its spatial, temporal, and geochemical characteristics. Our three-dimensional numerical models show that asthenospheric shear can excite upwelling and decompression melting at the tip of low-viscosity fingers that are propelled eastward by vigorous sublithospheric flow. This shear-driven upwelling is able to sustain intraplate volcanism that progresses toward the MOR, spreads laterally close to the axis, and weakly continues on the opposite plate. These predictions can explain the anomalously fast eastward progression of volcanism, and its spatial distribution near the SEPR. Moreover, for a heterogeneous mantle source involving a fertile component, the predicted systematics of volcanism can explain the geochemical trend along Pukapuka and the enriched anomaly of SEPR mid-oceanic ridge basalt at 16°–20.5°S. Our study highlights the role of horizontal asthenospheric flow and mantle heterogeneity in producing linear chains of intraplate volcanism independent of a (deep-rooted) buoyancy source. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.