A review of available paleomagnetic data from stable South America reveals a serious deficiency of data for the Late Cretaceous and a complete lack od data for the Early Tertiary. The Patagonian basalt plateau contains flat-lying basalt and basaltic andesites ranging in age from Late Cretaceous through Early Tertiary. The region is far inboard of the Andean Range and has been essentially unaffected by tectonic activity from the Late Mesozoic to present. Preliminary paleomagnetic data from one Late Cretaceous and one Early Tertiary sequence demonstrate that these volcanic sequences possess a very stable characteristic component of natural remanent magnetization which is almost certainly a thermoremanence acquired during original cooling. A one year project of through collection and analysis of paleomagnetic samples from the Patagonian basalt plateau will be carried out. The resulting data will: (1) fill a severe gap in knowledge of the apparent polar wander path for South America; (2) provide much more reliable reference poles for present and future paleomagnetic studies of the Andean orogen; and (3) provide much needed input data for global syntheses of plate motions with respect to the geomagnetic field reference frame.
