Sicily to Tunisia

12 Mar 2012

In a book picked up from a charity shop, Art and History of Egypt by Alberto Carlo Carpiceci, it begins with some extraordinary geological information on the Mediterranean basin. The Italians would be more concerned with this part of the world than people over against the Atlantic seaboard. It says that in the Palaeolithic era the Mediterranean Sea was cut into two basins - divided by a tongue of land that joined Tunisia and Italy, the islands of Malta being a remnant. This is not obvious from a map of the sea floor, Atlas of the Oceans, as it can be seen that Malta and the continental shelf off Sicily were once dry land and a huge area of fairly shallow water lies off Tunisia - but it is separated from Malta by a deep channel.

Carpiceci coninues - an immense ring of forests surrounded the Mediterranean, even the Nile Valley. European and North African fauna co-existed until between 10,000 and 80000BC some kind of cataclysm changed the face of this part of the world. The land bridge betweeen Tunisia and Sicily sank - leaving the islands of Malta poking out of the sea. In North Africa the thick forest began to dwindle and lakes and streams dried up - just a few thousand years ago.

The Maltese islands in the Multi Media Encyclopedia - see where it says that some 6.5 million years ago there was a land bridge between Malta and Sicily/Italy, possibly connecting Africa too. This was the situation through much of the Plioceneand there is evidence of rivers that once flowed. About 2 million years ago the Pleistocene Ice Ages began when ice locked up in the north is supposed to have led to lower global sea levels - lower by some 150m (in the Mediterranean). Hence, Malta would have been connected to Sicily and Italy. At some points in the Pleistocene Malta must have been isolated as dwarfism developed among mammal species and gigantism among rodents and lizards etc (as it did on other Mediterranean islands). The Pleistocene is a period of time that was inserted in order to accommodate the Ice Ages (at 100,000 year intervals) - which is interesting in respect of what was just said about the Pliocene. Malta did not have any ice but it did have a series of pluvial periods (wet climate episodes). The complete was on occasion characterised by cool summers and warmer winters when the forest zone currently located in central Europe, to the north, was instead located in a circle around the Mediterranean. Another climate regime involved unsettled summers (lots of rain) as if the jet stream was much further south to what it is nowadays - with obvious analogies. We can suppose this regime was in place during the Late Glacial Maximum when the ice sheet covered a large part of NW Europe and NE Canada. This was followed by a rapid return to present day conditions with a decline in precipitation befitting the Mediterranean. However, the article then claims, in a somewhat contradictory fashion, that during the Ice Ages the Maltese climate was arid and vegetation was sparse - punctuated by the wetter pluvials. Does this imply a largely semi desert regime? Apparently not so, the arid and dry conditions reflect an atmosphere that was more dusty (and globally it is thought to have been drier and deserts were larger). Now, we know that the Younger Dryas was much more dusty than the prior and after periods and the same seems to apply to the various Heinrich periods that dot the last 70,000 years or so. Is this what caused the dry and arid phases seen in the sediment layers in Maltese caves?

There is a nice diagram (page 5) which claims that in the Holocene (from 10,000 years ago) Malta has been separated from Sicily but in the Late Pleistocene, between 23,000 and 10,000 years ago, Malta was joined to Sicily and Italy. However, before that it was separated but way back in the last interglacial, from 150,000 to 125,000 years ago, it was connected to Sicily. Not only that, before 150,000 years ago Malta was connected to Sicily in one direction and to Tunisia and Libya in the other direction - and even to Sardinia.

At we are told the Apennines are the spine of Italy and the same chain of mountains runs through Sicily and ends up in Tunisia (mostly under the sea).