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- The Bemposta Migmatite Complex (Central-Iberian Zone, NE Portugal): a petrographic and geochemical studyPublication . Martins, Fábio André Craveiro; Damas, A.; Azevedo, M.R.; Gomes, Maria Elisa Preto; Valle Aguado, Beatriz; Nogueira Neto, J. A.ABSTRACT: The Bemposta Migmatite Complex (CMB) belong to the Central-Iberian Zone, NE Portugal. It is a high-grade metamorphic belt composed by metasediments of Ediacarian-Lower Cambrian age affected by partial melting during the second Variscan deformation event (D2). The anatexis culminated with intrusion of syn-tardi-D2 leucogranite sills in the CMB. Field and petrographic evidence suggest that the anatexis of the metasediments was controlled by muscovite dehydration-melting reactions. On the other hand, the stromatic leucosomes show that they were probably produced at a slightly deeper structural level (through biotite dehydration-melting reactions) and subsequently injected in these lithologies. The geochemical data reveals that leucosomes no longer correspond to the original melt compositions. During melt migration and ascent, they underwent fractional crystallization and accumulation of K-feldspar. Syn-tardi-D2 leucogranites that intrude CMB were most likely produced by higher degrees of partial melting. They have fractionated compositions and variable degrees of contamination with residual accessory mineral phases. Thus, CMB is interpreted as a Migmatite Injection Complex, where anatectic melts produced at slightly deeper levels were accumulated.