Skarn development in calcareous-pelitic succession affected by thermal metamorphism and fluid flow at Acquarilli beach (Elba Island, Italy)

Skarn deposits represent one of the most significant ore types occurring throughout the world. Skarn mineralization is formed as a consequence of the emplacement of magmatic bodies at relatively shallow depth which trigger metamorphic and metasomatic reaction involving both intrusive host rocks in the presence of magmatic- and/ or metamorphic-derived fluid. In the Elba Island (Tuscan Archipelago, Italy), two magmatic bodies intruded into the upper crust (c. 6 km depth): the Monte Capanne (western side) and the Porto Azzurro (eastern side) monzogranite plutons, dated at c. 7.2 and 6.5 Ma, respectively. Acquarilli beach (near Norsi locality, north–west of Capoliveri) can be considered one of the best geosites highlighting how metamorphic and metasomatic processes, linked to the emplacement of the Porto Azzurro magmatic body, affected selected beds of an original sedimentary succession made up of siliceous limestone alternated with shale. Two different skarn types can be recognised at outcrop scale.