Van Dijk and Fernandez search for siderites

Van Dijk and Fernandez search for siderites

Joep van Dijk and Alvaro Fernandez in Argentina

Researchers Joep van Dijk (left) and Alvaro Fernandez look for siderite minerals in the soils marking the Paleocene-Eocene boundary in Jujuy, Argentina. An international research team, which includes Timothy White, research professor in Penn State's Earth and Environmental Systems Institute, used siderites to reconstruct the climate nearly 56 million years ago.

IMAGE: Stefano Bernasconi/ETH Zurich