====== Messinian salinity crisis ======

The //Messianian Salinity Crisis// refers to very large deposits of sea salt found in the Mediterranean region, about 1km below the current sea bed.  (Named after //Messina//, a southern Italian city, where the deposits were first identified)

The salt deposits are around 50 times greater (at around a million cubic kilometres) than would be expected if the whole Mediterranean sea had evaporated at some stage.

The enormous quantities of salt are thought to have come from //mutiple //evaporation and refilling events of the Mediterranean basin. Probably around 500 million years ago.

Because the repeated filling episodes (from the Atlantic) would have cut extremely deep gorges - which are not present - the geological mechanisms are hard to explain. But various possible explanations have been put forward :

>Several possible causes of the series of Messinian crises have been considered. While there is disagreement on all fronts, the most general consensus seems to agree that climate had a role in forcing the periodic filling and emptying of the basins, and that tectonic factors must have played a part in controlling the height of the sills restricting flow between the Atlantic and Mediterranean (Gargani and Rigollet, 2007).<sup> </sup>The magnitude and extent of these effects, however, is widely open to interpretation (see, e.g., van Dijk et al. (1998)"\\ \\ Source : [[https://en.wikipedia.org/wiki/Messinian_salinity_crisis#Causes|Wikipedia]]

For technical details, see this research report in //[[https://www.nature.com/articles/nature10651|Nature]] //volume 480, pages 359–363 ( a full copy of which may be found  [[https://docs.google.com/uc?id=0B_xuyENh5ksFN2MwYWE5YjUtNzNkOS00OGZlLWFkMDYtOWMxYTViYjRiZjc0&export=download&hl=en|here]] {{:oa_padlock_grn.png?16&nolink|Open Access}})

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Also see : [[content:earth_sciences:salt_deposits]]