A method for palinspastic reconstruction of
rift basins is described here. It is based on the
assumption of isostatic equilibrium and calculated from the present topography and sediment
thickness in a rift basin. Passive continental
margins along eastern South America
and western Africa were moved landward from
the ocean-continent boundary approximately
100 km. When South America is rotated to
Africa, a tight fit with Africa results along the
northern and central margins of South America.
The southern part of South America was rotated
to fit against Africa based on the palinspastic reconstruction of the San Jorge,
Colorado and Salado marginal rift basins in
Argentina. The method could also be applied
to passive margins to calculate the total amount
of crustal stretching that occurred during
continental extension and rifting. The pre-rift
condition of passive margins could then be
calculated for more accurate initial fits between conjugate passive margins
