%0 Journal Article
%A Orejana García, David
%A Villaseca González, Carlos
%A Billstrom, Kjell
%A Paterson, Bruce A.
%T Petrogenesis of Permian alkaline lamprophyres and diabasesfrom the Spanish Central System and their geodynamic contextwithin western Europe
%D 2008
%@ 0010-7999
%U https://hdl.handle.net/20.500.14352/49620
%X Basic to ultrabasic alkaline lamprophyres anddiabases intruded within the Spanish Central System (SCS)during Upper Permian. Their high LREE, LILE and HFSEcontents, together with positive Nb–Ta anomalies, linktheir origin with the infiltration of sublithospheric K-richfluids. These alkaline dykes may be classified in two distinctgroups according to the Sr–Nd isotope ratios: (1) adepleted PREMA-like asthenospheric component, and (2) aBSE-like lithospheric component. A slight enrichment inradiogenic 207Pb and 208Pb allows the contribution of arecycled crustal or lithospheric component in the mantlesources. The intrusion of this alkaline magmatism is likelyto have occurred due to adiabatic decompression andmantle upwelling in the context of the widespread riftingdeveloped from Carboniferous to Permian in westernEurope. The clear differences in the geochemical affinity ofLower Permian basic magmas from north-western andsouth-western Europe might be interpreted in terms of amore extensive separation of both regions during thatperiod, until they were assembled during Upper Permian.
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