Textural evidence of peperites inside pillow lavas at Acicastello Castle Rock (Mt. Etna, Sicily)

Globular and microglobular peperites, with mingled sediment in millimetric to decimetric domains, are described from inside pillow lavas at Acicastello Castle Rock, Mt. Etna, Sicily for the first time. The peperites now comprise basalt and minor remnants of fine-grained detrital material, with smectite and zeolite crystallised during late hydrothermal activity. We propose that peperites formed when the magma, ascending towards the surface, intruded and intermixed with the unconsolidated wet Pleistocene bluish marly clays of the substrate. Subsequently they were transported by the uprising magma from the source region towards the surface, where they are preserved in pillow lavas.