Despite the written records that give clues to the location of Helike, a principal city of ancient Greece in the Bronze Age, it was not until 2001 that scientists finally found traces of the lost city (the Classical site) under an inland lagoon after more than a century’s speculation about the actual site. Astonishingly, scientists of Helike Project also discovered a well-preserved Early Bronze Age (EBA) city nearby (in Saitis area) dating back to 2400 BC.
An excavation site at the ancient Greek city of Helike
Ancient written accounts attributed the destruction of Helike to Poseidon, the Greek God of the sea and earthquakes, who brought an earthquake followed by a large tsunami in 373 BC. Through the analysis of microfauna assemblages, archaeologists were able to confirm the incidents that obliterated the city and reconstructed the environmental history of the ancient sites. The indicator species, whose presence or absence reflects specific environmental conditions, of Helike Delta are ostracods (Crustacea) and foraminifers (Protozoas). Their distribution is influenced by the salinity (freshwater, brackish or marine environments), temperature, oxygen levels or food availability. The microfossils are calcareous (resistant to decomposition) with low tolerance levels towards the environment (high sensitivity), thus accurately reflecting the microclimate with our assumption that their responsiveness to the environment is similar to that of the living species.
By gathering sediment samples and selecting paleoenvironmental indicators, researchers found that the sediment indicates a wide range of aquatic environments. Species with varied tolerance levels coexisting suggests transitional zones, maybe nearshore waters with seasonally different input of freshwater; terrestrial snail shells in aquatic microfauna assemblages indicate reworking of sediments from different environments (extreme case of damaged shells suggests tsunami transportation). Microfossil samples are also used to propose a stratigraphic correlation. Brackish water sediments (usually found below sea level) found above sea level show that the Helike Delta experienced tectonic shift (earthquake); majority of reworked shells from brackish water shows that the reworking was possibly due to wave action (tsunami) instead of run off from storms and floods.
Scanned micrographs of paleoenvrionmental microfauna indicators
Researchers thus carefully reconstructed the environmental conditions of Helike, concluding that submergence of EPA city, possibly a nearshore environment, was caused by earthquake, while sedimentation and tectonic activity caused its nearby area to reemerge as dry land and occupied by human populations in historical times. The Classical site was buried in a lagoon by the strong earthquake along with a powerful tsunami, and the sedimentation by the demolition continually uplifted the area, forming today’s Helike Delta.
Microfauna analysis showed its strength in use for deducing the past environment compared to the ambiguity of macrofauna which could be transported to the area. By conjecturing what the local environment of an archaeological site was like, researchers could not only reconstruct historical events of the rise and fall of ancient cities or geographical distribution of the land, but also further deduce how humans lived because environment, which determines food source, influences human lifestyle and activity (hunting, fishing…) to a great extent.
References:
Alvarez-Zarikian, C. A., Soter, S., & Katsonopoulou, D. (2008). Recurrent Submergence and Uplift in the Area of Ancient Helike, Gulf of Corinth, Greece: Microfaunal and Archaeological Evidence. Journal of Coastal Research, 1, 110-125.
http://www.ancient-origins.net/ancient-places-europe/uncovering-lost-city-helike-002510
https://en.wikipedia.org/wiki/Helike
Images:
Alvarez-Zarikian, C. A., Soter, S., & Katsonopoulou, D. (2008). Recurrent Submergence and Uplift in the Area of Ancient Helike, Gulf of Corinth, Greece: Microfaunal and Archaeological Evidence. Journal of Coastal Research, 1, 110-125.
Further readings:
https://historyandsoon.wordpress.com/2015/10/22/uncovering-the-lost-city-of-helike/ (including videos analyzing microscopic life that shed light on the Helike mystery).