Layers of change

Graduate student Evelyn Mervine traveled to Oman recently to study an area of uplifted ocean crust exposed to the atmosphere, the Samail Ophiolite. The photo shows accumulated layers of travertine, an alteration in the rock that draws carbon dioxide from the air—with a tape measure indicating depth. Mervine is studying the formation of travertine, seeking to understand its role in the global carbon cycle.
(Photo by Evelyn Mervine, Woods Hole Oceanographic Institution)