The nearest anyone has come to explaining the origins of the remarkable rocks of the Meteora – meaning suspended in air in Greek – is the German geologist Alfred Philippson. In 1897, he suggested that a river once ran into an ancient lake that covered what is now the plain of Thessaly, depositing in the same place where the Meteora have risen its rippling debris of silt, gravel, mud and water-smoothed pebbles and stones. Some 60 million years ago the river’s estuary was an alluvial fan that opened and spread from its point of entry into the lake. Over the course of thousands of years the layers of the fan deepened, eventually being compressed by the immense forces of water and earth into conglomerate – a type of sedimentary rock composed of the pre-existing stones that the river had washed into the lake – that was concreted together by hardened sandstone.
When a massive earthquake emptied the Thessalian lake by cleaving open a channel to the Aegean Sea, the deltaic cone at the end of the river was raised from the lake bed into the sky. Loose sandstone was rinsed away by rain and the stone pillars were further worn into their present sinuous forms, riddled and pocked with caves and fault lines, by wind, weather and subsequent movements of the earth.– from Notes from Near and Far by Julian Hoffman