Many of the precambrian shields or cratons are transgressed by "mobile belts" that have been the loci of deformation and metamorphism subsequent to craton formation. These belts are generally consistent with an origin by plate collision at former plate margins, however, the style and relative displacements associated with these collisions are not well constrained. This renewal will continue a paleomagnetic and Ar/Ar age dating program from rock units on opposite sides of the Brasilian mobile belt. Results, combined with existing data from the extension of the Brazilian belt in west Africa, the Pharusian belt, will allow assessment of the displacement and timing associated with a possible late Proterozoic continental collision.