Using sediment samples collected in the Bay of Biscay, scientists from the University of Cambridge, the University of Bordeaux and several other French institutions have been able to build up an accurate picture of the so-called Fleuve Manche, a prehistoric ‘super river’ that carved out the English Channel.

Previous studies in coastal Europe had pointed to the existence of the river during a series of ice ages that began around 450,000 years ago. It was formed following the overflow of a huge glacial in the North Sea, as water surged into the basin between Britain and France, scouring out the chalky rock. The river met the ocean in the Bay of Biscay, discharging the sediments collected for the new study, which revealed conclusively that it existed between three different ice ages 450,000, 160,000 and 90,000–30,000 years ago. 

‘This is the first time we have looked at what flowed out of the channel and into the bay during these crucial periods, said Professor Phil Gibbard of the University of Cambridge. ‘It provides the final piece of the puzzle, forming a complete record that reconstructs the dramatic events that cut Britain off from Europe and gave it its island status.’

February 2010