From the International Herald Tribune: Microbes eating away at pieces of history.

At Angkor Wat, the dancers’ feet are crumbling.

The palatial 12th-century Hindu temple, shrouded in the jungles of Cambodia, has played host to a thriving community of cyanobacteria ever since unsightly lichens were cleaned off its walls nearly 20 years ago. The microbes have not been good guests.

These bacteria (Gloeocapsa) not only stain the stone black, they also increase the water absorbed by the shale in morning monsoon rains and the heat absorbed when the sun comes out. The result, says Thomas Warscheid, a geomicrobiologist based in Germany, is a daily expansion and contraction cycle that cracks the temple’s facade and its internal structure. Warscheid, who has studied Angkor Wat for more than a decade, said in an interview that these pendulum swings had broken away parts of celestial dancer sculptures on the temple walls.

"It is getting worse — up to 60 or 70 percent of the temple is black," he added.

Once chalked up to weathering, the damage at Angkor Wat is now seen as [continue]