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The Monte Croce pluton (MCP), in the centraleastern Southern Alps, belongs to a large calcalkaline magmatic association of Permian age also including the Bressanone, Ivigna, Cima d'Asta and Monte Sabion granitoid intrusions, as well as the Atesina volcanics. The MCP was intruded into the lowmedium grade basement of the Southern Alps, at depths corresponding to a crystallization pressure of about 3.1±0.6 kbar. Rb/Sr biotite dating yields a value of 273±3 Ma for the intrusion age. The MCP consists of mediumgrained to porphyritic biotite±hornblende granodiorite/monzogranite (GD) con taining mafic microgranular enclaves (MME) of tonalitic to granodioritic composition. Field, petrographic and mineralogical evidence strongly supports a model of extensive interaction between partially crystallized mafic and felsic magmas, with incorporation, fragmentation and dispersal (ie mingling±mixing) of the mafic component into the granitic host magma. The occurrence of mafic enclaves having distinct textures and particular compositions for the Ferich biotite and amphibole, suggests that at least two pulses of hybridized intermediate magmas were involved in the petrogenesis of the Monte Croce granitoids. The GD and the hosted MME are metaluminous to weakly peraluminous granitoids with highK calcalkaline affinity, mostly following linear trends on Harker diagrams. On chondritenormalized spider diagrams, both GD and MME show patterns with low HFSE/(LILE, LREE) ratios and distinct Ba, Nb, Sr, P, and Ti negative spikes, similar to those of orogenic suites. Initial 87Sr/86Sr ratios range from 0.7086 to 0.7114 in the GD, and from 0.7080 to 0.7099 …