Victory through silt

Alexander the Great had ''Mother Nature'' on his side when he conquered the island fortress of Tyre in 332 BC . . .

Now archeologists have at last worked out how Alexander's engineers managed to build a causeway to enable his army to conquer what had become a bastion of resistance. . .

Archaeologists have known for some time that Alexander used the debris of the abandoned mainland city to build a causeway 3,000 yards long and up to 180 yards across. Once within reach of the city walls, he used siege engines to batter and finally breach the fortifications.

But building a causeway in deep water would have meant raising the level of the sea floor considerably - an impossible feat in such a short space of time. However, researchers in France who analysed the coastal sediment record for the past 10,000 years have discovered how Alexander's engineers exploited a natural underwater "sandbridge".

The ''sandbridges'' are formed when sediment is deposited rapidly at a spot behind an island.

Posted by David on May 17, 2007 10:06 AM