The salt rivers of the Crotone area, a marvel of tourism and geological research

CROTONE Zinga is a small hilly part of the municipality of Casabona in the Crotone area. The houses are up on the rock, and they were even more so when the entire inhabited core stood on a real natural “castrum”, then abandoned after an earthquake. Some remains of the walls are still visible. It would be an anonymous village if it weren’t for a phenomenon only recorded here in Italy and in a few other parts of the world: salt water diapirism. A “diapiro” is a molten rock that rises to the surface through layers of other, denser rocks. And in Zinga this happens with salt. The town’s attraction is actually the “saline diapiri”, real rivers of saltsome solidified, others still “alive”, which can be admired with a short walk of a few kilometers, just outside the city, in the valley of the Vitravo river, now almost dry.
The geologist Mario Cimieri is doing work with the Italia Nostra group to involve residents and tourists to improve these places. “This site is unique in Europe in extension and sizebecause there are several salt diapirs and it is the only one in Italy where the phenomenon has been observed”, says the geologist toOuch.
“They are evaporating rocks – he explains – linked to a geological event which took place 5.6 million years ago, the Messinian salinity crisis, this is when the Strait of Gibraltar closed due to tectonic movements and the Mediterranean no longer exchanged water with the colder Atlantic. And then – says Cimieri – the Mediterranean began to evaporate and turned into a huge salt lake”. And meanwhile, as we descend from the ridge towards the valley, we begin to glimpse the white of the salt that “seeps” from the darker rocks. “All these areas were submerged by the sea, and the presence of diapirs and many fossils tell us this which is still easily found in these Hills ». Cimieri bends down to pick up a stone. He turns it over and discovers the remains of a petrified shell. He puts the stone back in its place and we continue down into the valley. “The salt is therefore deposited and compacted by the sediments above it, and little by little though it began to float upwards because it was lighter than the other stones – explains the geologist – also thanks to the tectonic movements. The preferred channels for the ascent are fractures and faults ».
You arrive right next to the water of the river, and from a hole in the rock you can clearly see the flow of salt, almost petrified, which then concentrates in a kind of pond. White. Immaculate. It looks like snow. “Today again some village elders come to collect the salt here because they say it’s better than what you buy – says Cimieri – and it’s true that it’s very clean. Until the 60s it was exploited industrially, there were shallow mines, as salt is also found on the surface. And there are still the ruins of the Guardia di Finanza barracks, which controlled the extraction of salt ».
But why are the Zinga diapirs important? “Because in these salt formations, microdroplets of water dating back more than 5 and a half million years ago have been found, which contains small algae. In short, life! And it was possible to highlight – adds the geologist – the levels of salinity and temperature in the Mediterranean at that time, thanks to studies carried out by Rocco Dominici and Mara Cipriani from the University of Calabria ». But there have been also researchers who came here from other parts of the world, to observe and study this phenomenon. What is most surprising is the saline diapiro of Russomanno, one of the localities in the valley. It almost seems to observe the small Dolomites, with their sharp peaks shining under the reflections of the sunlight. “This one is different from the others – says Cimieri – it has a different aspect: it is more translucent, it has a greater presence of salt. Diapirs were formed over a period of about 200,000 years, therefore each in different ways over time’.
But what will be the future of this geosite? “As an association” Italia Nostra – Casabona and Valle del Neto “we focus on a form of geotourism, to make this place known to everyone – says Mario Cimieri – so that here you can live a naturalistic and also a geological experience, to also interest the new generations. Who knows, maybe we’ll intercept future geologists’. (Ouch)

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