Subduction of the ridge beneath South America is thought to have caused the Pampean flat-slab and its associated inland tectonic deformation and reduced magmatic activity.[1][2]
von Huene, R.; Corvalán, J.; Flueh, E. R.; Hinz, K.; Korstgard, J.; Ranero, C. R.; Weinrebe, W. (1997), "Tectonic control of the subducting Juan Fernández Ridge on the Andean margin near Valparaiso, Chile", Tectonics, 16 (3): 474–488, Bibcode:1997Tecto..16..474V, doi:10.1029/96TC03703, S2CID129668321