GROUNDWATER GEOCHEMISTRY AND WATER RITUAL AT THE TEMPLES OF APOLLO AT DELPHI, DIDYMA, AND CLAROS

This paper presents new geochemical results from a multiyear study of groundwater at the three most influential oracular centers in the ancient Greek and Roman world, the Temple of Apollo at Delphi, Didyma, and Claros. The aqueous geochemical data from each site is linked to: a) the regional geology that instills the observed geochemistry; b) the divination ritual recorded by observers in antiquity; and c) the general settlement, land-, and water-use history. This study reveals that the mosaic of ore deposits in close proximity to both Claros and Didyma infuses groundwater with injurious concentrations of several metals and metalloids, namely arsenic (As), antimony (Sb), and lead (Pb). Authors who documented these sites in antiquity—Iamblichus, Pliny, Tactitus, Pausanius, Diodorus, Plutarch, and others—report the important role groundwater played in the divination process. According to these sources, ingestion of water from specific springs located near or inside the temples effectively catalyzed the connection between the ordinary and the supernatural, facilitating divinely inspired prophesy. At Claros, Pliny reflects that the water “which causes marvelous oracular utterances to be produced” greatly shortened the lives of those that consumed it. The geochemical results presented in this study substantiate his observations. The geochemical character of water resources also affected settlement systems and land-use practices at each site. Claros only existed as an isolated sanctuary in antiquity, never developing into a substantial settlement. In contrast, Delphi, with its salubrious springs, witnessed multiple iterations of settlements spanning from the Late Bronze Age (ca. 1700 BCE) to the late 19^th Century CE. Oracular responses from Delphi, Didyma, and Claros influenced ancient Greek and Roman societies in both intangible and palpable ways. Wars were fought, distant lands colonized, and religious groups persecuted after oracular consultations. Deciphering the geochemistry of groundwater from these sites revealed the capacity of abiotic ecosystem components to influence elements of culture and health. The three case studies also illustrate the interlocking of socio-cultural systems with hydrologic systems and further our understanding of the relationship between humans and hydrosphere.