On May 26 - June 2, 2007, the Polish Salt Mining Association organized another scientific expedition under the slogan SICILY 2007, devoted to research on contemporary and fossil evaporites and methods of their exploitation.

The route of the expedition, in which 17 members of the Association participated (representing mining plants, scientific and academic institutions as well as state administration units dealing with salt issues), ran through the area of Sicily, where there are very rich deposits of rock salts of the Messina age (end of the Neogene, their formation dates back to the period between 6.08 Ma and 5.5 Ma, formed in the youngest salt "giant" in the geological history of the Earth) and salt is obtained in the process of evaporation of sea water in numerous coastal salt pans.

Education and methods of rock salt exploitation were studied in the underground (adit system from the surface to a depth of 500 m, the length of the excavations reaches 70 km) in the Realmonte mine near Agrigento. Here, using the blasting method (chambers up to 7.5 m high), an inclined (sometimes plastically disturbed) seam of rock salt is mined with a thickness of 400-600 m (annual production reaches 60,000 tons), with a content of 98-99% NaCl and the share of insoluble parts ( clay, anhydrite, polyhalite) up to 1.5%. The salt series is divided in the central part by a set of up to 100 m thick, consisting of 6 kainite-polyhalite seams (up to 18 m thick) interbedded with rock salt. Underlying and overlying the salt complex, the Messinian clay-sulfate-carbonate formations with a rich set of sedimentary structures (e.g. laminated "balatino"-type sulfate formations, selenite gypsum and gypsum arenites with wrinkled layers) and microfauna were visible in the coastal cliffs in the area of Siculiana. Brine pools (there are currently 40 pools in operation covering an area of 25 km2 and producing up to 1-1.5 thousand tons of salt per year in two 3-month cycles, but salt extraction in this area was carried out as early as the 7th century BCh.) and a small museum in Nubia near Trapani made it possible to trace the process of selective concentration of sea water up to the precipitation of sodium chloride and old (still used in many salt pans today!) techniques of extracting salt from brine pools and its packaging.

Observations of volcanic phenomena associated with the submarine rift stretching along the eastern edge of Sicily were an important point of the scientific program of the expedition. Observations were carried out both on active volcanic cones, such as the formation and development of eruptive formations (lava flows and pyroclasts in the form of ash, sand, lapilli and volcanic bombs) on the slopes of Etna and on the dormant volcano Vulcano in the Aeolian Islands. At the edge of the Wulkano crater, next to layers of lavas, glazes and volcanic ashes (and lateritic deposits developed on them), there are hydrogen sulphide fumaroles accompanied by concentrations of native sulfur, and at the foot of the volcano, in the beach and coastal zone - hot mud-sulphur pools and underwater emissions gas (hydrogen sulphide, carbon monoxide) of medicinal importance. On the island of Lipari, a gigantic (over 200 m thick) layer of pumice, lying on the slope of the former cone and until recently exploited, attracted attention. The walls of the Alkantara river gorge in the region of Taormina (cut in the old covers of basalt lavas flowing from Mount Etna) showed the internal structure of the former lava flows, with different directions of lava flow emphasized by the blow characteristic of basalts.

The scientific program of the expedition was complemented by a rich tourist program, enabling the visit to the most important monuments of the island, illustrating its rich and complicated history (from the Phoenicians, through the Greeks, Romans, Arabs and Normans, to modern times!). The ruins of temples and theaters in Taormina, Syracuse, Segesta, palaces, monasteries and churches in Messina, Syracuse, Noto, Erica, Monreale, Palermo, narrow streets of towns like Lipari, Erice or Taormina - where time stopped tens or centuries ago! – give Sicily a unique atmosphere.

Krzysztof Bukowski, Stanisław Burliga, Grzegorz Czapowski, Hanna Tomassi-Morawiec, Jacek Wachowiak