The Iberian Peninsula has some of the most extensive Cambrian outcrops in Europe (Lotze 1961c), including a diverse, continuous record of fossils and facies, and is thus a fundamental source of biostratigraphic information for the Cambrian System and its intercontinental correlations. Most exposures of Iberian Cambrian rocks occur in the Iberian Massif, but they are also known from the Pyrenees, the Catalonian Coastal Ranges and the Iberian Ranges (Fig. 3.1).
Many exposures are geographically isolated and/or show tectonic boundaries, and facies changes are common, and these characteristics have led to a profuse stratigraphic nomenclature (see Fig. 3.2; Zamarreño 1983;, Liñán et al. 1993a). Following Lotze (1961c), however, the Cambrian sequence can be overviewed as a diachronous Lower to Middle Cambrian carbonate sequence sandwiched by silici-clastic successions (Fig. 3.2). The lower of the siliciclastic units is entirely Lower Cambrian, whereas the upper unit ranges from upper Lower or Middle Cambrian to Upper Cambrian (Fig. 3.2). The Lower Cambrian series has been subdivided into the Corduban, Ovetian, Marianian and Bilbilian stages, and the Middle Cambrian series subdivided into the Leonian, Caesaraugustan and Languedocian stages (Fig. 3.2).
The Precambrian/Cambrian boundary stratotype was erected by the International Subcommission on Cambrian Stratigraphy (ISCS) at the Fortune Head section in eastern Newfoundland (Canada) with the first appearance datum (FAD) of Phycodes (= Trichophycus) pedum (Landing 1994). This FAD coincides with behavioural changes, increased