The Argentine Precordillera: A Traveler from the Ouachita Embayment of North American Laurentia
The Argentine Precordillera is a continental fragment rifted from the Ouachita embayment of the southern margin of Laurentia (North America) during Cambrian time [about 515 million years ago (Ma)] and accreted to the western margin of Gondwana (South America) during Ordovician time (about 455 Ma). Similarities of Cambrian stratigraphic successions and faunas, Grenville basement rocks, and dimensions link the Argentine Precordillera to the Ouachita embayment. Evidence of rifting during Cambrian time and of a wide ocean basin during Ordovician time indicates that the Precordillera traveled as an independent microcontinent to collide with Gondwana.
Thomas
WA
W. A. Thomas is in the Department of Geological Sciences, University of Kentucky, Lexington, Kentucky 40506-0053, USA. R. A. Astini is at the Catedra de Estratigrafia y Geologia Historica, Facultad de Ciencias Exactas, Fisicas, y Naturales, Universidad Nacional de Cordoba, Avenida Velez Sarsfield 299 Casilla de Correo 395, 5000 Cordoba, Argentina.
Astini
RA