Iron Deposits on Palea Kameni

November 06, 2005

2638

Provided by: Enver Murad, Bayerisches Landesamt für Umwelt
Summary authors & editors: Enver Murad

The Santorini island group (Greece) in the southern Aegean Sea is renowned for its volcanic phenomena. A violent eruption some 3,600 years ago covered the original island with a thick layer of pumice and created a flooded caldera. Subsequent lava eruptions starting in 197 B.C. formed two small islands, Palea Kameni and Nea Kameni, in the center of the caldera. Hot fumarolic exhalations that contain sulfur dioxide persist to the present day and have resulted in an aggressive environment that leaches numerous elements, among them iron, from the rocks constituting these islands. If such exhalations emerge into the cool and more or less neutral submarine environment, selected precipitation of the leached components will take place, which is the case at several localities along the coasts of Nea and Palea Kameni. The most spectacular of these precipitates is an up to 3 meter thick ochreous deposit that has accumulated in a narrow bay on Palea Kameni. The upper, oxidized zone of this deposit is of a striking rusty, yellow-brown colour and consists mainly of the iron oxyhydroxides, goethite and ferrihydrite, as well as siderite, an iron carbonate. The locals used to shy away from this bay, but in the age of inflationary tourism, the sediment is now touted as a “warm therapeutic mud.” For an overview of Santorini see EPOD for 08/25/2005.

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