A Major Change in the Stratigraphy of the Santorini Volcano in Greece

Abstract

Two prominent and similar pumice series were described on Thera in 1879— the Upper and Lower Pumice Series (UPS and LPS). Since then, geologists have treated the two series separately because they seemingly occurred at distinct levels and had different ages. Here we show that these two pumice series are identical; there is no LPS on Santorini. All stratigraphic conclusions based on the LPS from Santorini should therefore be discarded. The water-filled Santorini caldera with its steep inner slopes existed before the eruption. Volcano-tectonic effects in connection with caldera formation created concentric terraces that were mantled by the products of the Late Bronze Age (LBA) eruption. Subsequent erosion only left remnants of the mantle behind. Topographic effects followed by slumping during sedimentation caused confusion of the stratigraphy on the caldera wall. Our results are supported by geological, paleontological and archaeological evidence. Furthermore, the caldera with its minerals, pigments, harbours and hot springs was accessible for the Thereans. This reinterpretation opens new perspectives for archaeological research. The catastrophic LBA eruption (previously called the Minoan eruption) destroyed a flourishing culture on Santorini and impacted neighbouring cultures around 1613 BC.