PALEOMAGNETISM OF PERMIAN AND TRIASSIC RED BEDS OF NW SPAIN AND IMPLICATIONS FOR THE TECTONIC EVOLUTION OF THE ASTURIAN-CANTABRIAN ARC

A palaeomagnetic study of Permo-Triassic cover rocks in the Asturian-C antabrian Are has revealed characteristic magnetizations in 136 sample s from 14 sites, yielding a mean palaeopole for each of the three regi ons studied (Cabo de Penas, Villaviciosa, and Tudanca). Previous work on remagnetized Palaeozoic formations in the area revealed Permian (or younger) tightening of the Are on the basis of palaeomagnetic declina tions that show relative rotations of more than 100 degrees. According to the new palaeopoles obtained in this study, these rotations are no t present to any comparable extent in the Permo-Triassic deposits, all owing us to conclude that the bulk of the rotations in the Are is Perm ian in age.