Thera olive tree recounts life 60,000 years ago

THESSALONIKI – The oldest olive tree in the world, which had remained underground on Thera for 60,000 years, stole the show at the recent Philoxenia 2004 tourism exhibition in Thessaloniki. The only exhibit to travel from Santorini, it fascinated thousands of visitors with the sight of a plant fossil taken from the walls of the caldera. Hundreds of domesticated olive, mastic and pistachio trees that were preserved in the volcanic ash of successive eruptions thousands of years ago have been revealed by Athens University researchers, who are documenting the island’s natural resources, geological monuments, geotopes and geological heritage. The rare paleobotanical finds that the team retrieved from the quarries of Fira over a decade of research are heavily freighted with scientific and museological significance, mainly because they contain valuable information about the flora and climatic conditions of the Cyclades at that time. The plant fossils that were found in layers of volcanic ash 60,000 years old were isolated by special conservation methods, Evangelos Velitzelos, head of Athens University’s Department of Historical Geology and Paleontology, told Kathimerini. Apart from leaves of the European olive, there were accumulations of leaves from two types of palm trees (the dwarf palm and the Cretan palm tree, or Phoenix Theophrasti, which survives at Vai on Crete), mastic and tamarisk trees. The fossilized flora found in the volcanic ash indicates that the prevailing climate was warm, without harsh winters. «The climate of Santorini 60,000 years ago was very warm, not even Mediterranean but subtropical,» said Velitzelos. Repeated volcanic eruptions covered the island’s flora in layers of ash, he explained. «Plants with thin leaves were destroyed, while the rest began the process of fossilization. Plants with tough leaves, such as olives or palms, retained their original epidermis in most cases. That is why we able to determine their genus and species with such certainty.» The plant fossils were discovered at an old pumice quarry on the outskirts of Fira, and three new plant fossil sites were recently located in abandoned quarries elsewhere on the promontory. The later finds uncovered a new species of plant, Ramnos alaternos, and others, which are being studied. Volcanic plaque on the wall of the caldera in the Old Fira quarries contains feathers, leaves and olive stones, refuting the view that the trees at that time did not bear fruit. There is evidence of plant fossils at Akrotiri and Thirasia, where rescue digs are needed «to save the largest possible number of plant fossils from the rare geotope and geological monument of Santorini,» said the professor. Fossil finds from the caldera are already on display at the Prehistory Museum of Santorini and the island’s Cultural Association, the Fossilized Forest Natural History Museum of Mytilene and the Museum of the Olive and Greek Oil in Sparta, but there is enough paleobotanical material for a paleontology museum on Santorini. The Santorini municipality and experts are examining a proposal for such a museum to highlight the Aegean’s plant history.