John R. Hale

New evidence for the geological origins of the ancient Delphic oracle (Greece)

Ancient tradition linked the Delphic oracle in Greece to specific geological phenomena, including a fissure in the bedrock, intoxicating gaseous emissions, and a spring. Despite testimony by ancient authors, many modern scholars have dismissed these traditional accounts as mistaken or fraudulent. This paper presents the results of an interdisciplinary study that has succeeded in locating young faults at the oracle site and has also identified the prophetic vapor as an emission of light hydrocarbon gases generated in the underlying strata of bituminous limestone.

The Delphic Oracle: A Multidisciplinary Defense of the Gaseous Vent Theory

Ancient historical references consistently describe an intoxicating gas, produced by a cavern in the ground, as the source of the power at the oracle of Delphi. These ancient writings are supported by a series of associated geological findings. Chemical analysis of the spring waters and travertine deposits at the site show these gases to be the light hydrocarbon gases methane, ethane, and ethylene. The effects of inhaling ethylene, a major anesthetic gas in the mid-20th century, are similar to those described in the ancient writings. We believe the probable cause of the trancelike state of the Priestess (the Pythia) at the oracle of Delphi during her mantic sessions was produced by inhaling ethylene gas or a mixture of ethylene and ethane from a naturally occurring vent of geological origin.

The Geological Origins of the Oracle at Delphi, Greece

Abstract Ancient authors from Plato to Pausanias have left descriptions of Delphi’s oracle and its mantic sessions. The latter were interpreted as events in which the Pythia (priestess) placed herself on a tripod over a cleft (fissure) in the ground below the Apollo temple. Here she inhaled a vapour rising from the cleft, and became inspired with the power of prophecy. French archaeologists who excavated the oracle site at the turn of the century reported no evidence of either fissures or gaseous emissions and concluded that the ancient accounts were myths. As a result, modern classical scholars and many archaeologists reject the ancient testimonies concerning the mantic sessions and their geological origin. However, the geological conditions at the oracle site do not a priori exclude the early accounts. A major WNW-ESE fault zone and a minor swarm of NNW-SSE fractures intersect below the site. These intersection(s) provided pathways for rising ground water, including a spring below the Apollo temple. The faults broke through a bituminous limestone formation at relatively shallow depth. Hydrocarbon gases that originated in this formation may have escaped during and after seismo-tectonic events. Such gases can induce mild narcotic effects. It is highly probable therefore that the Pythia’s inspiration resulted from the inhalation of light hydrocarbon gases, which rose along a fissure (fracture) in the adyton below the Apollo temple.