Palaeomagnetism of Palaeozoic rocks from the Cabo de Penas, Asturia, Spain

Abstract

Ordovician volcanic samples of the Cab0 de Penas area yielded a primary remanent magnetization (D = 202", I = 78', ag5 = 6') which is partially or entirely overprinted by a Late Palaeozoic remagnetization.Late Devonian-Early Carboniferous sedimentary samples reveal a pre-or syntectonic Carboniferous remanent magnetization similar to the secondary one of the volcanic samples.A soft post-tectonic component appears also in few samples, for which a Late Carboniferous age is inferred.Comparison of the Carboniferous remanent magnetizations and structural parameters suggests that in a late stage of the deformation, the sites have undergone minor rotations around a vertical axis.A 'strike correction' is therefore proposed to take such an effect into account.The average of the corrected mean-site directions (D = 178", I = 19', og5 = 9") is considered to be a good approximation of the Early or Middle Carboniferous palaeomagnetic direction in Asturia.' series end up with a volcano-detritic succession, including basaltic lavas in the upper part.Then, there is an uninterrupted period of sedimentation up to Early Carboniferous times, with large amounts of fossils giving well-determined stratigraphical ages.Several periods of red sedimentation occur in the sequence.In particular the Siluro-Devonian 'Furada'