Ice Age Graveyard

25 Jan 2011

The Daily Telegraph (see www.telegraph.co.uk January 23rd) ... construction of a dam on a reservoir near Aspen high in the Colorado mountains, has led to the discovery, so far, of 600 bones preserved in sediment at the bottom of what was an Ice Age lake. Mastadon, bison, deer, and a ground sloth are among the remains, the bones still white and pieces of trees with bark still on the branches and leaves that have been preserved in an uncurled green condition. The stock explanation has been trotted out by scientists - many of the animals drowned after going to the waters edge to drink. Experts (not the use of that word in the report) say the animals may have been walking across a frozen surface of the lake when it cracked and they disappeared beneath the ice and were were preserved in the sediments at the bottom. However, the report says there were a variety of fossils from different environments - or at least two different eco-systems. Mammoth and Mastodon aren't usually found together. This suggests more than one deposition event. At one stage there was mastadon, ground sloth and deer, covered in five feet of peat. The forest eco-system changed and the lake became a marsh and in that sediment there were mammoths - or this is the way it is being interpreted at the moment. Contrary to the popular image of the Ice Age this part of North America was not a frozen wasteland. A large amount of plant matter, fossilised insects and small vertebrae have been found preserved in the deposit, a veritable wonderland for palaeontologists.