The Late Neoproterozoic magmatism in the Ediacaran series of the Eastern Pyrenees: new ages and isotope geochemistry

Abstract

Geochronological U-Pb (LA-ICP-MS), geochemical and isotopic data from metavolcanic felsic rocks of the Canigó and Cap de Creus massifs in the Eastern Pyrenees provide evidence of an Ediacaran magmatic event lasting 30 Ma in NE Iberia. These data also constrain the age of the Late Neoproterozoic succession in the Cap de Creus massif, where depositional ages range from 577 to 558 Ma, and in the Canigó massif, where the data (575-568 Ma) represent minimum ages. The geochemistry of the felsic rocks indicates that they were formed in a back-arc environment and they record a fragment of a long-lived subduction-related magmatic arc (620-520 Ma) in the active northern Gondwana margin. The homogeneity shown by all these crustal fragments along this margin suggests that the individualization of the Pyrenean basement from the Iberian Massif started later, probably during its transition from an active to a passive margin in Cambro-Ordovician times.