The Chimney Gwenen
Juan de Fuca Ridge, northeastern Pacific Ocean
These are two halves of the top of Gwenen, a five story-high spire that was venting water at 179 degrees Centigrade. It bristled with a profusion of tube worms and other animals, vestiges of which can still be seen on its surface. The microbes on which these animals lived were sustained by the hot, nutrient-rich water that leaked out the sides of the chimney. As the chimney grew, built up irregularly by minerals precipitating from the water, animals were trapped and buried in the walls. The holes on the left are places where core samples were taken for study of the microbial community that once lived in the chimney.