Paleomagnetismo de la Formación Chon Aike: estabilidad de Patagonia con respecto a América del Sur desde al menos el Jurásico Tardío

CARLA PUIGDOMENECH; RUBÉN SOMOZA; GRAEME K. TAYLOR; EMILIANO RENDA; HAROLDO VIZÁN; MIGUEL HALLER; VÍCTOR RUIZ GONZÁLEZ; BÁRBARA BOLTSHAUSER; CLAUDIA ZAFFARANA; RAÚL FERNANDEZ

Tucuman

Congreso; XX Congreso Geológico Argentino; 2017

We report paleomagnetic results from 34 sites of ca 155 Ma ignimbrites in the Deseado Massif, southern Patagonia. Although the paleomagnetic data may not fully average out the secular variation of the paleofield, the computed time-averaged paleomagnetic vector yields a paleopole indistinguishable from Late Jurassic and Early to mid-Cretaceous poles of South America, strongly suggesting that a) Patagonia has been in its present-day position with respect to the main continent since at least the Late Jurassic; and b) the continent has had negligible polar drift during a period of ca 60 m.y. in those times. Applying appropriate reconstructions of the South and Central Atlantic Ocean the results further indicate that ~155 Ma poles of South America (Patagonia) and North America are compatible with a GAD geometry of the paleofield.