Paleomagnetismo de la Fromación Chon Aike: Estabilidad de Patagonia respecto a américa del Sur desde el Jurásico tardío

TAYLOR G.K.; BOLTSHAUSER, BÁRBARA; HALLER M.; VIZÁN H.; RUÍZ GONZÁLES V.; FERNÁNDEZ R.; ZAFFARANA C.B.; PUIGDOMENECH C.G.

Congreso; XX Congreso Geológico Argentino; 2017

The aim of this work is to report paleomagnetic results from thirty four sites of ca 155 Ma ignimbrites in the Deseado Massif, southern Patagonia. After removing site-mean directions with a95 greater than 15° and VGPs loca? ted more than 45° from the full mean pole we obtained a palepole located at Lat. 86.3°S, Long. 183.4°E (A95 = 10.1°; K= 10; N= 23) which is 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.