The alkaline monzo-syenitic porphyries from the Spanish Central System (SCS) show a heterogeneous
composition ranging from basic to acid terms which give rise to major and trace element compositional
trends in accordance with fractional crystallization of amphibole, plagioclase, biotite, alkaline feldspar, Timagnetite
and apatite. The whole-rock geochemistry of the basic porphyries shows clear similarities with
respect to the SCS isotopically enriched alkaline lamprophyres, indicating that a genetic link between both
groups of dykes might exist. This relationship would probably represent an origin of the monzo-syenitic
porphyries after differentiation of parental lamprophyric magmas due to fractional crystallization