Towards reconstruction of the lost Late Bronze Age intra-caldera island of Santorini, Greece
Résumé
During the Late Bronze Age, the island of Santorini had a semi-closed caldera harbour inherited from
the 22 ka Cape Riva Plinian eruption, and a central island referred to as ‘Pre-Kameni’ after the presentday
Kameni 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 granulometry
and high-precision K-Ar dating. Furthermore, the topography of Late Bronze Age Santorini is
reconstructed by creating a new digital elevation model (DEM). Pre-Kameni and other parts of Santorini
were destroyed during the 3.6 ka Minoan eruption, and their fragments were incorporated as lithic
clasts 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 the
island started to grow at 20.2 ± 1.0 ka soon after the Cape Riva eruption. This implies a minimum longterm
lava extrusion rate of ~0.13–0.14 km3/ky during the growth of Pre-Kameni.
Domaines
Volcanologie
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