Petrogenesis of Permian alkaline lamprophyres and diabases from the Spanish Central System and their geodynamic context within western Europe

Basic to ultrabasic alkaline lamprophyres and\uddiabases intruded within the Spanish Central System (SCS)\udduring Upper Permian. Their high LREE, LILE and HFSE\udcontents, together with positive Nb–Ta anomalies, link\udtheir origin with the infiltration of sublithospheric K-rich\udfluids. These alkaline dykes may be classified in two distinct\udgroups according to the Sr–Nd isotope ratios: (1) a\uddepleted PREMA-like asthenospheric component, and (2) a\udBSE-like lithospheric component. A slight enrichment in\udradiogenic 207Pb and 208Pb allows the contribution of a\udrecycled crustal or lithospheric component in the mantle\udsources. The intrusion of this alkaline magmatism is likely\udto have occurred due to adiabatic decompression and\udmantle upwelling in the context of the widespread rifting\uddeveloped from Carboniferous to Permian in western\udEurope. The clear differences in the geochemical affinity of\udLower Permian basic magmas from north-western and\udsouth-western Europe might be interpreted in terms of a\udmore extensive separation of both regions during that\udperiod, until they were assembled during Upper Permian