The Rise of Continents: Megan Holycross

Megan Holycross, formerly a Peter Buck Fellow and National Science Foundation Fellow at the Smithsonian’s National Museum of Natural History and now an assistant professor at Cornell University, uses a special device—similar to a car jack—in a laboratory at the museum to bring an experiment to the pressures needed to stabilize the mineral garnet.

A study, published today in Science, uses laboratory experiments to show that the iron-depleted, oxidized chemistry typical of Earth’s continental crust likely did not come from crystallization of the mineral garnet, as a popular explanation proposed in 2018. The iron-poor composition of continental crust is a major reason why vast portions of the Earth’s surface stand above sea level as dry land, making terrestrial life possible today.