The study by Shelley and BossieÁre (2000) is an important
contribution to the discussion concerning the Ibero±Armorican
arc (IAA) generation model. This model comes as one
of a sequence of previous ideas already published in several
papers (Bard, 1971; Matte and Ribeiro, 1975; Lefort and
Ribeiro, 1980; Ribeiro et al., 1980; Burg et al., 1981;
Brun and Burg, 1982; Julivert, 1987; Ribeiro et al., 1990;
Dias and Ribeiro, 1995; Ribeiro et al., 1995; Silva, 1997). A
common feature of the interpretations in these papers is the
great importance attributed to two major transcurrent faults:
the dextral Porto±Tomar shear zone (PTSZ) and the sinistral
Tomar±Badajoz±Cordoba shear zone (BCSZ), to explain
the extension of the Iberian structures into the Armorican
Massif in the form of trace the arcuate shape of the IAA
