Santorini

During the development of the Santorini volcanic complex several huge eruptions have produced massive layers of pumice. Older deposits were deposited roughly 100'000 and 60'000 years ago and can be seen in some of the lower parts of the inner caldera wall (lower and miffle pumice layers).

More obvious, however, are the pumice layers of the great Minoan Eruption (1600 BC), which, in many parts of the island, lies ontop of all other volcanic deposits. Blocks of dark, older lava are embedded in most pumice layers. Until 1990 pumice was mined and exported, mainly as an ingredient to a type of cement which can harden under water and is resistant to seawater.

Erosion has sculptured pumice into remarkable shaps in various places on the islands, like in the picture above, taken on Thirasia. Differential weathering often forms curious patterns of holes on vertical cliff faces in the pumice, like in the picture below.