Fig. 3: Plate tectonic reconstructions of the South Atlantic from 85 to 45 Ma.
From: 40Ar/39Ar dating reveals over 30 million years of plume-ridge interaction formed the Rio Grande Rise
Reconstructions were made in GPlates72 using the rotation parameters of Zahirovic et al.73 and plotted in GMT70. Each dated panel shows the locations of dated samples from RGR (this study) and WR6,7,10,11,20,21. Symbol color denotes timing of volcanism relative to reconstruction age. Active volcanism (within 5 Myrs of the reconstruction time) is shown by red symbols, recently active (within 5-10 Myrs) by orange symbols, and inactive ( > 10 Myrs) by black symbols. The hatched region indicates the approximate area of a proposed microplate2 now incorporated into the South American plate. The red line is the paleo-MAR, white lines are fracture zones including PFZ Peleg Fracture Zone, RFZ Rachel Fracture Zone, and dashed black lines are isochrons (labeled in the 45 Ma plot with chron numbers and ages in Ma) from Seton et al.43.
