The Science of Salt The sprawling Realmonte Salt Mine of southern Sicily is a perfect location to ex
The Science of SaltThe sprawling Realmonte Salt Mine of southern Sicily is a perfect location to experience the engineering feats of both nature and man. With over 100 km of tunnel cut into salt deposits at depths of up to 300 ft below sea level, a number of sites are of particular interest.Salt deposits in the geological record are broadly referred to as evaporites, as they precipitate from solution (such as seawater) when rates of evaporation are high. Naturally this only occurs in hot, arid environments such as the Great Salt Lake in Utah and in many areas of the Middle Eastern region. During the deposition of these Sicilian salts approximately 5 million years ago, the Mediterranean was experiencing a phenomenon known as the Messinian Salinity Crisis. This was a period where the Mediterranean Ocean was blocked off from the Atlantic by plate tectonics, resulting in super-saline conditions of the Mediterranean Ocean as it effectively ‘dried-up’ and in turn facilitating the deposition of vast quantities of evaporites.The temperature at which a solution is evaporating can affect the type of salt which precipitates, meaning that a different type of salt is formed during the winter than during the summer. Thus, the light and dark salts seen in the walls of the mine actually represent summer vs. winter deposits respectively. These seasonal cycles are known as varves in the geological world, and create fascinating patterns in many outcrops worldwide. Here, subsequent deformation of these varve deposits has resulted in the extraordinary outcrop seen in the photo above (imagine cutting a flat plane through a dome/bowl-shape).In addition to the natural wonders of the Realmonte Salt Mine, the workers have painstakingly created their own contender for the most impressive site within the labyrinth of tunnels. The church is a hollowed-out hall which can cater for up to 800 people, and comes complete with pulpit, alter, and a number of incredibly detailed religious statues carved out of the walls. Ceremonies are held annually in early December to celebrate St Barbara, the patron saint of all underground workers.Regardless of religion, it is hard to argue that these miners are blessed to work in such a fascinating place.A.G.C.Image credit:http://bit.ly/1kuudpmhttp://bit.ly/1NWbyPQSources:http://bit.ly/1GVUkKN -- source link
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