Munching Microbes Cause Caves To Grow
Carlsbad Caverns in New Mexico jb10okie/Flickr CC by ND 2.0 For single-celled creatures, microbes are both industrious and ubiquitous. They are just about everywhere, from high up in the atmosphere, to deep below the planet's surface, and it turns out that these tiny lifeforms are able to shape the very Earth itself, just by eating. In a new study published in Chemical Geology, researchers took a look at a still-growing cave system in Italy. The cave was made of limestone, a type of rock that is easily dissolved by acids. The cave also contained hydrogen sulfide, a foul-smelling gas. While hydrogen sulfide can be poisonous to humans, to some types of microbes, it's a food source. Microbes in caves don't have access to other food sources like plants or algae that rely on the...