Evolución de Iberia durante el Jurásico a partir de datos paleomagnéticos

Resumen

New palaeomagnetic studies at 11 well-dated sedimentary sections (from the Iberian Ranges and the Betic Cordillera) and a review of published Jurassic palaeomagnetic data have been carried out in order to constrain the evolution of Iberia during the Jurassic. Two magnetic components were observed in the investigated rocks: A low-temperature component of normal polarity and maximum unblocking temperature of about 400-450QC which has been interpreted as a secondary Cretaceous or Tertiary remagnetisation. And a higher-temperature component (the ChRM) that was isolated from 450 up to 550-575QC. The ChRM exhibited both normal and reversed polarities. ChRM directions pass the fold test and the reversal test. Consistent results in paleolatitudes were obtained from both areas indicating high paleolatitudes for the Toarcian (close to the present palaeolatitude of Iberia) and lower for the Upper Jurassic. Paleomagnetic poles obtained from the Iberian Ranges have been transferred and compared with two segments of the North-American Apparent Polar Wander Path that have been proposed in the literature. Iberian results allow to discriminate between these two proposed segments.