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The subduction of bathymetric highs such as aseismic ridges, oceanic plateaus, and seamounts has been posited as the primary driver of flat slab subduction. [3] The Andean flat slab subduction zones, the Peruvian slab and the Pampean (Chilean) flat slab, are spatially correlated with the subduction of bathymetric highs, the Nazca Ridge and the Juan Fernandéz Ridge, respectively.
To the south, the CVZ is limited by the Pampean flat-slab segment or Norte Chico flat-slab segment, a region devoid of volcanism due to a lower subduction angle caused by the subduction of Juan Fernández Ridge. The CVZ is characterized by a continental crust that reaches a thickness of approximately 70 km (43 mi). [2]
Low angle subduction or flat-slab subduction has been common during the Andean orogeny leading to crustal shortening and deformation and the suppression of arc volcanism. Flat-slab subduction has occurred at different times in various part of the Andes, with northern Colombia (6–10° N), Ecuador (0–2° S), northern Peru (3–13° S) and ...
The subducting Nazca plate, which exhibits unusual flat slab subduction, is tearing as well as deforming as it is subducted (Barzangi and Isacks). The subduction has formed and continues to form the volcanic Andes Mountain Range. Deformation of the Nazca plate even affects the geography of Bolivia, far to the east (Tinker et al.).
Flat-slab subduction is ongoing beneath part of the Andes, causing segmentation of the Andean Volcanic Belt into four zones. The flat-slab subduction in northern Peru and the Norte Chico region of Chile is believed to be the result of the subduction of two buoyant aseismic ridges, the Nazca Ridge and the Juan Fernández Ridge, respectively
The Pampean flat-slab has also caused a lull in the volcanism in the Andes seen in the lack of modern volcanoes between the Central Andean Volcanic Zone and the Southern Andean Volcanic Zone. [3] As the flat slab migrated from west to east under South America, so did volcanic activity, until it vanished 1.9 Ma ago, about 750 kilometres (470 mi ...
The flat slab subduction associated with the Nazca Ridge has been linked to the cessation of volcanism in the Andes Mountains at about 4 Ma. [6] The subduction has also been linked with the formation of the Fitzcarrald Arch, which is a 400,000 km 2 (150,000 sq mi), 400 to 600 m (1,300 to 2,000 ft) high, domed topographic feature that defines ...
Despite being a typical location for calc-alkalic and subduction volcanism, the Andean Volcanic Belt has a large range of volcano-tectonic settings, such as rift systems, extensional zones, transpressional faults, subduction of mid-ocean ridges, and seamount chains apart from a large range of crustal thicknesses and magma ascent paths, and ...