. First Paleomagnetic Results on the Sarmiento Ophiolite, Southern Chile: Implications for the Patagonian Orocline

RAPALINI, AUGUSTO E.; CALDERÓN, MAURICIO; HERVÉ, FRANCISCO; CORDANI, UMBERTO; SINGER, SILVIA

BOLLETTINO DI GEOFISICA TEORICA ED APPLICATA

Istituto Nazionale di Oceanografia e di Geofisica Sperimentale

Lugar: Trieste, Italia; Año: 2004 vol. 45 p. 246 - 249

0006-6729

The Andean orogen presents a dramatic change of about 90° on its strike around 53°S, where from a dominantly roughly North-South direction to the north turns into an East-West orogen. This bend is known as the Patagonian Orocline, after Carey (1955). As already pointed out by Cunningham et al. (1991), a yet unresolved problem in the evolution of the Southern Andes is whether the Patagonian Orocline formed as a curved orogen, is a non-rotational arc with domains offset by strike-slip faults or it has been produced by orogenic rotation (“oroclinal bending”). Paleomagnetism is a very powerful tool to discriminate between such end-models and to unravel the kinematic evolution of an orocline both in space and time (see for instance Morris and Anderson, eds., 1998). Therefore, reliable paleomagnetic data from outcrops distributed along the whole Andean orogen between  50°S and 56°S would be significant for unravelling the tectonic evolution of this region.