Paleomagnetic data from volcanic rocks studied by Princeton University scientists at Mamainse Point in Ontario, Canada, are helping researchers understand continental motion during the assembly of the ancient supercontinent Rodinia. Here, Adam Maloof, an assistant professor of geosciences at Princeton, observes these rocks along the edge of Lake Superior as part of the study. (Photo: Nicholas Swanson-Hysell)

The well-exposed layering of basalt flows in formations near Lake Superior is aiding scientific understanding of the geomagnetic field in ancient times. Nicholas Swanson-Hysell, a Princeton graduate student, examines the details of the top of a lava flow. (Photo: Catherine Rose)