%0 Journal Article
%A Seghedi, I.
%A Brandle, J.L.
%A Szakács, A.
%A Ancochea Soto, Eumenio
%A Vaselli, O.
%T El manto litosférico en el sureste de España: aportaciones de los xenolitos englobados en rocas alcalinas del mioceno-plioceno
%D 2002
%@ 0213-683X
%U https://hdl.handle.net/20.500.14352/58292
%X Pliocene-Quaternary nephelinitic and alkali basaltic lavas and pyroclastic deposits from Cofrentes andTallante and Miocene lamproitic lavas from Aljorra host xenoliths and megacrysts of lithospheric mantleorigino The xenolith suite consists of spinel Iherzolites and harzburgites and with protogranular,porphyroclastic and equigranular or transitional (protogranular to porphyroclastic) textures. The texturalfeatures provide evidence of ductile-brittle deformation of Tallante xenoliths, whose mineralogy and mineralchemistry data (presence of kaersutite and phlogopite) also bear evidence of fluid-induced metasomatismof the lithospheric mantle. P-T estima tes suggests that mostly protogranular xenoliths are reliable to definea palaeogeotherm, which is from 950-1185°C at 2,5-3.0 epa, 794-805°C and 1,1-1,3 epa for Cofrentesto 936-958°C, at 1,1-1,2 epa for Tallantes. The Aljorra peridotite suggests a temperature of -880 oC anda pressure of -1,8 epa. The picture of equilibrium P-T conditions indicates that the differences in themantle lithosp-here composition is related to (1) its deformation state and (2) metasomatic events, but alsoto (3) the location of entrapment during magma ascent in the lithosphere generated by diapiric uprising ofasthenospheric mantle. The location of the entrainment is either close to the magma generation area or issituated at the mantle-crust boundary.
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