[en] The Santa Eulalia batholith (Alto Alentejo, Portugal) is a plutonic complex of lateVariscan age located in the Northern part of the Ossa-Morena Zone. This pluton is made up of granites grouped in two facies: (i) the external granite, formed by granites showing equigranulartexture, dominant K-feldspar and biotite as the main mafic mineral, (ii) the central granite, has equigranular texture and a biotite ? muscovite asociation. Several gabbro-diorite and granodioritetonaliteigneous bodies also occur. The external granite shows a ring-type outcrop pattern, and includes most of the gabbro-diorite and tonalite-granodiorite rocks as well as large metasedimentary country rocks. The central granite forms a circular outcrop and is totally surrounded by the external granite. The data available suggest that all of the igneous units formingthis batholith are coeval although petrogenetically independent. We propose that the gabbrodioriterocks derive from an enriched mantle source. These rocks show no or little crustal contamination. Partial melting in the low-middle crust of mafic/gneissic lithologies and intermediate igneous/metasedimentary lithologies generated the tonalite-granodiorite rocks and the granite rocks of the pluton respectively. The emplacement in the upper crust probably startedwith the gabbro-diorite and tonalite-granodiorite igneous magmas, being followed almostsimultaneously by the external granite. The central granite might have intruded shortly after the extenal granite, pushing aside all of the previous units and thus generating the annular outcroppattern.

[es] El plut?n de Santa Eulalia (Alto Alentejo, Portugal) constituye un complejo intrusivode edad tardi-varisca emplazado en el l?mite septentrional de la zona de Ossa-Morena. Est? formadopor dos facies gran?ticas: (i) granito externo, de textura equigranular, con feldespato pot?sicopredominante y biotita y (ii) granito central, de textura equigranular, biot?tico y con escasa moscovita. Tambi?n aparecen una serie de cuerpos ?gneos gabro-dior?ticos y granodior?ticotonal?ticos, dispuestos en configuraci?n anular y mayoritariamente incluidos en el granito externo.Aparecen enclaves de considerables dimensiones formados por metasedimentos provenientesdel encajante. Considerando los datos previos y el estudio de campo, petrogr?fico y geoqu?micorealizado, se propone que las diferentes unidades ?gneas que integran el plut?n son contempor?neasen su emplazamiento pero independientes petrogen?ticamente. Se propone que las rocas gabrodior?ticas derivan de un manto enriquecido y presentan escasa contaminaci?n cortical. Procesos de fusi?n parcial en la corteza inferior-media afectando litolog?as ?gneas m?ficas y ne?sicas pudieron formar las rocas granodior?tico-tonal?ticas del plut?n. Estos mismos procesos afectandoa litolog?as ?gneas de composici?n intermedia y metasedimentos pudieron dar origen a las rocasgran?ticas. El emplazamiento de los magmas gabro-dior?ticos y granodior?tico-tonal?ticos pudoocurrir primero, aunque fue aproximadamente simult?neo con la intrusi?n del granito externo.De forma contempor?nea, aunque ligeramente m?s tard?a se emplazar?a el granito central desplazando las rocas previamente emplazadas hacia la periferia del plut?n, gener?ndose as? laconfiguraci?n anular observada.