Magmatism in the Asunción-Sapucai-Villarrica Graben (Eastern Paraguay) Revisited: Petrological, Geophysical, Geochemical, and Geodynamic Inferences
Figure 10
(a) General map, including ASV, showing contours (red lines) of the depth (km) of the subducting Nazca slab based on seismic data of [96]. Heavy lines (black) outline the Cretaceous rift systems. The hatched area roughly marks the extension of intense early Paleozoic reworking of Proterozoic material, but the exact border to the Brazilian Craton remains unknown [97]. Pink fields delineate inferred positions of major cratonic fragments below Phanerozoic cover [98]: AAB, Arequipa-Antofalla; AC, Amazon Craton; AB, Apa Block; PR, Paranapanema; LP, Rio de la Plata; PA, Pampia. (b) Seismic tomography image [99] across a profile approximately at 24° Lat. S. Note that the low-velocity feature in the mantle to the East has been interpreted as a fossil mantle plume [100].
