Chilean flat slab subduction controlled by overriding plate thickness and trench rollback

Research Article| January 01, 2012 Chilean flat slab subduction controlled by overriding plate thickness and trench rollback Vlad C. Manea; Vlad C. Manea * 1Computational Geodynamics Laboratory, Centro de Geociencias, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, México *E-mail: vlad@geociencias. unam. mx; vladₘanea@yahoo. com. Search for other works by this author on: GSW Google Scholar Marta Pérez-Gussinyé; Marta Pérez-Gussinyé 2Department of Earth Sciences, Royal Holloway, University of London, Egham Hill, TW20 0EX Egham, UK Search for other works by this author on: GSW Google Scholar Marina Manea Marina Manea 1Computational Geodynamics Laboratory, Centro de Geociencias, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, México Search for other works by this author on: GSW Google Scholar Author and Article Information Vlad C. Manea * 1Computational Geodynamics Laboratory, Centro de Geociencias, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, México Marta Pérez-Gussinyé 2Department of Earth Sciences, Royal Holloway, University of London, Egham Hill, TW20 0EX Egham, UK Marina Manea 1Computational Geodynamics Laboratory, Centro de Geociencias, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, México *E-mail: vlad@geociencias. unam. mx; vladₘanea@yahoo. com. Publisher: Geological Society of America Received: 09 Jun 2011 Revision Received: 02 Aug 2011 Accepted: 16 Aug 2011 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2012 Geological Society of America Geology (2012) 40 (1): 35–38. https: //doi. org/10. 1130/G32543. 1 Article history Received: 09 Jun 2011 Revision Received: 02 Aug 2011 Accepted: 16 Aug 2011 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Vlad C. Manea, Marta Pérez-Gussinyé, Marina Manea; Chilean flat slab subduction controlled by overriding plate thickness and trench rollback. Geology 2012;; 40 (1): 35–38. doi: https: //doi. org/10. 1130/G32543. 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 How flat slab geometries are generated has been long debated. It has been suggested that trenchward motion of thick cratons in some areas of South America and Cenozoic North America progressively closed the asthenospheric wedge and induced flat subduction. Here we develop time-dependent numerical experiments to explore how trenchward motion of thick cratons may result in flat subduction. We find that as the craton approaches the trench and the wedge closes, two opposite phenomena control slab geometry: the suction between ocean and continent increases, favoring slab flattening, while the mantle confined within the closing wedge dynamically pushes the slab backward and steepens it. When the slab retreats, as in the Peru and Chile flat slabs, the wedge closure rate and dynamic push are small and suction forces generate, in some cases, flat subduction. We model the past 30 m. y. of subduction in the Chilean flat slab area and demonstrate that trenchward motion of thick lithosphere, 200–300 km, currently ∼700–800 km away from the Peru-Chile Trench, reproduces a slab geometry that fits the stress pattern, seismicity distribution, and temporal and spatial evolution of deformation and volcanism in the region. We also suggest that varying trench kinematics may explain some differing slab geometries along South America. When the trench is stationary or advances, the mantle flow within the closing wedge strongly pushes the slab backward and steepens it, possibly explaining the absence of flat subduction in the Bolivian orocline. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.