Abstract

Two families of dykes are distinguished in the Taliga-Barcarrota area with directions NW-SE and
E-W (the younger one). Chemical affinity is tholeiitic shifting from Ol+Hy normative in the first to
Q+Hy normative in the second. A K-Ar whole rock age gives 250±5 M. A. (i.e. Upper Permian).
Evolution by olivine and minor pyroxene fractionation is proposed. These dykes likely represent
an earlier post Hercynian ensialic extensional magmatism which should be taken into a account
in any geodynamic model of post Hercynian evolution of the Iberian Peninsula.