PALEOMAGNETIC EVIDENCE OF AN EARLY PALEOZOIC ROTATED TERRANE IN NORTHWEST ARGENTINA - A CLUE FOR GONDWANA-LAURENTIA INTERACTION

Paleomagnetic results from three Lower Ordovician units in northwest A rgentina are reported. When assessed with available geologic evidence, these data permit the definition of the Puna Oriental-Famatina rotate d terrane. Paleogeographic reconstructions based on these paleomagneti c results place Puna Oriental-Famatina in the South Iapetus ocean, clo se to the Gondwana margin and near some of the Lower-Middle Ordovician Central Mobile belt terranes of the Northern Appalachians, The accret ion of Puna Oriental-Famatina may have resulted from the closure of th is ocean in Middle Ordovician time.