20 August 2006

Bolivian dinosaur tracks

Did you know that the largest site for dinosaur footprints is in Bolivia? Unfortunately, however, that the site is in danger from erosion:
"It surpasses anything I've ever seen," said palaeontologist Christian Meyer, the director of Basel's Natural History Museum, who led the first team of scientists to map the site in 1998.

Around 68 million years ago herds of dinosaurs used to flock to Cal Orck'o, then a lakeside, in search of food and fresh water.

They left behind an extremely rich geological record: 350 trackways of over 5,000 footprints belonging to 330 different species.

Not to fear, though; a Swiss engineering firm, Gasser Felstechnik - the folks who recently secured the rock above the highway leading to the Gotthard tunnel - have been called in to protect the footprints.
To combat the damage caused by rainwater seeping through the cracks from above, the cliff-face at Cal Orck'o has been covered with a layer of clay and plastic. Plants have been ripped out and a layer of protective Goretex-like webbing is being tested. Detectors have been installed to measure movement.

The Swiss team is intending to sink up to 900 five-metre long, zinc-plated nails into the rockface to prevent its collapse. But this could be problematic.

"We are still trying to find machinery and heavy equipment to stabilise the wall, but nothing is available in South America," Meyer said. "But our main goal is to stop quarry workers from continuing to blast away – sometimes they are only 20 metres from the wall," he explained.

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