Towards reconstruction of the lost Late Bronze Age intra-caldera island of Santorini, Greece

co-auteur étrangerInternational audienceDuring the Late Bronze Age, the island of Santorini had a semi-closed caldera harbour inherited fromthe 22 ka Cape Riva Plinian eruption, and a central island referred to as ‘Pre-Kameni’ after the presentdayKameni Islands. Here, the size and age of the intracaldera island prior to the Late Bronze Age(Minoan) eruption are constrained using a photo-statistical method, complemented by granulometryand high-precision K-Ar dating. Furthermore, the topography of Late Bronze Age Santorini isreconstructed by creating a new digital elevation model (DEM). Pre-Kameni and other parts of Santoriniwere destroyed during the 3.6 ka Minoan eruption, and their fragments were incorporated as lithicclasts in the Minoan pyroclastic deposits. Photo-statistical analysis and granulometry of these lithics,differentiated by lithology, constrain the volume of Pre-Kameni to 2.2–2.5 km3. Applying the Cassignol-Gillot K-Ar dating technique to the most characteristic black glassy andesite lithics, we propose that theisland started to grow at 20.2 ± 1.0 ka soon after the Cape Riva eruption. This implies a minimum longtermlava extrusion rate of ~0.13–0.14 km3/ky during the growth of Pre-Kameni