mantle structure Argentina 8 Tectonics 8 Magnetotellurics 6 Structural geology 6 magnetotelluric method 6 slab 6 Electrical conductivity 4 Electrically conductive 4 Volcanoes 4 electrical conductivity 4 subduction zone 4 upper mantle 4 Altiplano 2 Altiplano-Puna 2 Andes 2 Annealing 2 Basalt 2 Basaltic volcanism 2 Benioff zone 2 Birefringence 2 Bouguer anomaly 2 Conjugate gradient algorithms 2 Constrained inversions 2 Convergent plate boundaries 2 Crustal thickness 2 Crystal preferred orientations 2 Crystallographic preferred orientations 2 Deformation 2 Densification 2