Resumen de Evolución petrogenética del magmatismo básico mesozoico en las Zonas Externas de las Cordilleras Béticas (S. España)

Diego Antonio Morata Céspedes, Encarnación Puga Rodríguez, Alain Demant, Luis Aguirre le Bert

• Mesozoic basic magmatism from the Externa/ Zones of the Betic Cordilleras consisted of two magmatic events. The first one began at the end of the Triassic and the second developed during the Jurassic. Whole-rock geochemical characteristics and primary mineralogical compositions allow to define a tholeiitic affinity far the Triassic magmatism and a transitional to alkaline affinity far the Jurassic magmatism. Trace e/ement ratios evidence an incompatible e/ement enriched source ((La/Ce),, > 1, La/Nb < 1.5) far both the Triassic and }urassic magmatisms. Moreover, differences in other trace e/ement ratios (Th/Nb, Th/Yb, Zr/Nb, Zr/Y, Ba/Zr, etc.) indicate a higher influence of a lithospheric component far the Triassic magmatism regarding to the Jurassic magmatism. This temporal evo/ution of the magmatism, is related with the distensive events which affected the Sudiberic margin during the Mesozoic, in relation with the opening of the Central Atlantic ocean.