Major geodynamic and sedimentary constraints on the chronostratigraphic correlation of the lower-middle Cambrian transition in the western Mediterranean region

摘要

The sedimentary rocks of the lower-middle Cambrian transition in the western Mediterranean region have recorded a superposition of extensive tectonic, volcanic, epeirogenic, and eustatic events that led to a complex sequence framework that, in some cases, makes detailed chronostratigraphic correlations difficult. This paper summarizes and updates the relationships between event stratigraphy, fluctuations of relative sea level, setting of major stratigraphic discontinuities, unconformities, and condensed levels, and succession of benthic community replacements displayed by outcrops located in the Iberian Peninsula (Iberian, Cantabrian and Córdoba platforms), Moroccan Atlas (Souss Basin), and the Montagne-Noire and Sardinian platforms. The resulting mosaic of inter-related geodynamic processes is correlated by trilobite, archaeocyath-and acritarch-based chronostratigraphic scales, taking as reference for the base of the Middle Cambrian in West Gondwana the immigration of paradoxidid trilobites.