Ice Ages

The New York Times (see www.nytimes.com/2010/12/18/world/middleeast/18deadsea.html ) has picked up on the story of the Dead Sea sediment cores that are currently being drilled out of the middle of what is the world's deepest inland basin. The first bore hole is thought to have passed through four Ice Ages, some 400,000 years. The cores will be sent to Germany for analysis so the above date is a bit of guesswork. What emerges is going to be very interesting in respect of the Ice Ages – and indeed, for the hypothesis there is a 100,000 year cycle of ice sheet growth and retraction. The C14 methodology of dating is useless after 40,000 years ago – and probably for the period leading up to that date. However, minerals common to the Dead Sea enable a different dating method – but this is not described. Already, from just a rough look at the cores, it is clear there were varying levels of salt and mud representing dry phases and wet ones. A fragment of wood was found in some sand indicating, it was said, it had been carried into the Dead Sea during a flood event. A layer of gravel was also found, dating between 50,000 and 100,000 years ago which might suggest the lake virtually disappeared at one point.