Hydrothermal sedimentation in the caldera of Santorini, Hellenic Volcanic Arc

Abstract

ABSTRACTSediments in the caldera of Santorini are receiving a hydrothermal input of iron and manganese from presently active hydrothermal vents off the Kameni Islands, and are enriched in these elements in their surface layer. However, greater Fe‐Mn enrichments occur in discrete layers at depth in the cores separated from the surface by Fe‐Mn poor sediments, suggesting that a past hydrothermal event may have been more intense than the present one. The buried Fe‐Mn enriched layers occur above a turbidite thought to have resulted from sediment slumping due to a major volcanic eruption and earthquake in 1650, and are thought to have formed consequent on the activation of faults related to the magma chamber by the eruption facilitating seawater‐rock interaction processes and the formation of metal‐rich hydrothermal solutions.