THE BIRTH AND EVOLUTION OF THE MEDITERRANEAN
The formation of the Mediterranean basin up until the present has been
by no means a simple process
The formation of the Mediterranean basin up until the present has been
by no means a simple process
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As we can see from the earthquakes which occur along its shores and the slow but constant increase in sea level, is definitely not yet completed. In the Mediterranean, ancient and recent history are superimposed upon one another, revealing a dynamic sea, more like a mosaic composed of interlocking ridgess, trenches, basins and islands,born of a succession, sometimes protracted and sometimes sudden, but all on a geological scale whose commonest units of measurement are intervals of a million years. Once again, the main agents responsible for the creation of the Mediterranean were the movements of the plates which make up the earth's surface . |
Floating like huge rafts above the earth's mantle, over time they changed the shape,the dimensions and the position of both land masses and oceans. The mechanism has remained unchanged for billions of years and, judging by the movements still going on on the earth's surface - where continents are still drifting together, moving apart and breaking up, new oceans are being formed - is still going on today. The titanic jigsaw puzzle ofthe plates led, around 65 million years ago, to the formation of the ancestral Mediterranean, made up roughly of the intermediate part of the Tethys, between the Atlantic and the Pacific. |
At the beginning of the Palaeocene the seas began gradually to retreat, leaving huge areas out of the water, but they were destined to be submerged once again during a new phase of encroachment in the Eocene (55 million years ago) period, when Europe was once again invaded by shallow seas. This was not a rapid phenomenon, but a continuous series of oscillations in the sea level, similar to gigantic tidal waves, which drew the waters into areas like present-day Germany and Russia, which up until then had always been out of the water. Fossils show that these aquatic and continental areas were inhabited by organisms similar, or even identical, in shape and biology, to the ones which live in our planet's seas today. ln fact in that period the Mediterranean was one of the centers of differentiation and of the diffusion of marine molluscs, both bivalves and gastropods, which were able to spread throughout the whole of the Tethys, thanks to the equatorial currents from the east and those heading in the opposite direction which bathed the African and Asian shorelines. By comparing ancient and current flora and fauna, it has been possible to reconstruct the climatic and environmental conditions of that geological period.
The distribution and the abundance of coral barriers and the remainsof tropical-type vegetation lead to the hypothesis that the Mediterranean of the time had a hot climate, where coral fish swam and the aquatic algae and plants were like those of the present Indo-Pacific area. The "Pesciara"at Bolca, in Verona, Italy, is in fact a petrified sea of the Eocene era, as its famous fossil deposits show. If we could transport ourselves back to the shores of the primordial Mediterranean and dive in its waters, it would feel very similar to divingon the seabed of the Red Sea or the Maldives or the Great Barrier Reef in Australia. The scene before our eyes would be one of sections of coral reef made of colonies of stony corals such as Goniastrea, Goniopora, Euphyllia, Stylophora and blue corals like the Heliopora amongst which would swim Nautilus with their triangular shells, batfish (Platax sp.), rabbitfish (Siganus sp.), carangids, burrfish, surgeonfish, trumpetfish and soldierfish.