Structure of the Castellaccio Pluton (Asinara Island, Italy)

This paper illustrates the geological and structural map (scale 1:10,000) of the Castellaccio Pluton (Asinara island – Italy), a peraluminous granodioritic intrusion of Variscan age that belongs to the Corsica-Sardinia Batholith. This small pluton, about 15 km2, emplaced within Paleozoic amphibolite-facies rocks during the post-collisional exhumation of the chain. The map shows the fine details of the magmatic structure of the pluton. Field-structural survey, coupled with remote sensing and major-elements geochemical mapping, allowed to recognize the occurrence of five magmatic units and the magmatic flow trajectories within the pluton. These outcomes provide useful insights into the architecture of the magmatic system. The results presented improve substantially the cartographic database of the Variscan crust of Sardinia and, finally, may serve as a robust background supporting further studies on the emplacement mechanism, or targeted to more specific petrologic studies.