Aseismic ridge subduction focused late Cenozoic exhumation above the Peruvian flat slab

Late Miocene Exhumation of the Western Cordillera, Ecuador, Driven by Increased Coupling Between the Subducting Carnegie Ridge and the South American Continent

“…The subduction of bathymetric highs has been suggested to trigger widespread deformation and uplift at subduction margins (e.g., Dominguez et al., 1998; George et al., 2023; Lallemand et al., 1992; Ramos, 2005; Rosenbaum & Mo, 2011; von Huene et al., 1997). In addition, the subduction of oceanic aseismic ridges also appears to cause changes in the geochemical composition of magmatism with a shift to a more juvenile isotope signal in magmas (Chiaradia et al., 2020).…”

“…In Costa Rica, the subduction of the aseismic Cocos Ridge was associated with the growth of a bivergent orogenic wedge and localized rock uplift (Morell et al, 2012). In northern Peru similar processes have taken place: Miocene uplift and exhumation of the Western Cordillera and contemporaneous deformation of the sub-Andean ranges was associated with the onset of subduction of the Nazca Ridge and subsequent slab flattening (George et al, 2023;Margirier et al, 2015). The Nazca Ridge is furthermore suggested to promote localized shortening in the overriding plate in southern Peru (Sébrier et al, 1988).…”

“…While the influence of aseismic ridge subduction in the forearc and foreland regions is reasonably well documented, the influence of ridge subduction with respect to the high-elevation regions of the northern Andes has remained uncertain. Some authors suggest that the subduction of the Nazca Ridge and subsequent slab flattening triggered regional uplift in the Western Cordillera and the sub-Andean ranges of northern Peru (e.g., Bishop et al, 2018;George et al, 2023;Margirier et al, 2015); similarly, other authors have linked uplift and exhumation of the Eastern Cordillera in Ecuador and Colombia to ridge subduction (Spikings et al, 2001(Spikings et al, , 2010Spikings & Simpson, 2014). However, owing to pulses of shortening unrelated to ridge subduction in the eastern Andes (e.g., Mégard, 1984;Sébrier et al, 1988), an unambiguous link between exhumation and ridge subduction in the northern Andes does not exist.…”

Coupling Between Exhumation and Subduction: A Case Study From the Southern Great Xing'an Range, NE Asia

“…These processes embody the coupling between deep subduction into the mantle, deformation within the crust, and climatic changes in the hydrosphere at convergent plate boundaries (Barnes et al., 2012; Spikings & Simpson, 2014; Stalder et al., 2020). A multi‐disciplinary approach encompassing diverse fields such as magmatic evolution, sedimentary basin analysis, paleoclimate studies and low‐temperature thermochronology is thus required to explore the coupling between subduction and the overlying lithosphere (e.g., Barnes et al., 2012; George et al., 2022).…”

“…At convergent plate boundaries, the configuration of the subduction system plays a profound role in the formation and migration of regional stress fields, tectonic deformation, topography and magmatism on the overlying plate (Bendick & Ehlers, 2014; Cassel et al., 2018; Conrad & Lithgow‐Bertelloni, 2002; Saylor et al., 2023). Flat‐slab subduction triggers compression (thus exhumation) (Axen et al., 2018; Dávila & Lithgow‐Bertelloni, 2015) such as in the Central Andean Plateau (e.g., George et al., 2022), while roll‐back of the subducted plate induces (migrating) extension and associated magmatism and exhumation (Buiter et al., 2002; Gvirtzman & Nur, 1999) such as in the North American Cordillera (e.g., Coney and Reynolds, 1997). In addition, subduction‐related deformation modifies the regional topography of the overriding plate, which in turn affects the regional precipitation regime, thus affecting denudation and exhumation (Barnes et al., 2012; Clift, 2010; Jepson et al., 2021).…”