AMHERST, Mass. - Laurie Brown, professor of geosciences at the University of Massachusetts, has received a Fulbright Research Scholarship which will take her to Norway for six months during the year 2000. She will conduct research at the prestigious Norwegian Geologic Survey in Trondheim. Her work has previously taken her to locations as diverse as the Adirondacks, the Southwestern United States, Hawaii, and South America.
A geophysicist, Brown’s primary interest is in paleomagnetism - the magnetic signature that is embedded in rocks when they’re formed. This signature shows scientists exactly where on the Earth the rocks were formed relative to the North Pole. This information can help scientists map where the continents have drifted over millions of years. "We know that the continents have moved and continue to move," Brown said.
Scientists theorize that roughly a billion years ago, the seven continents sat together in one "supercontinent." Brown’s research supports this theory: rocks in Norway and the Adirondack Mountains, which are of the same age, carry extremely similar magnetic signatures, Brown said. This indicates that they may have been geographically near each other when they gained their magnetization. Scientists also suspect the supercontinent broke apart about 550 million years ago. Brown’s upcoming work may shed some light on when such a split may have occurred.
Brown and her students collect samples from outcroppings; that is, sections of rock still attached to the Earth. The researchers drill inch-wide cylinders of rock, then cut the cylinders into inch-long segments that are marked to note where they were situated, related to the present North Pole. In the lab, the magnetic signature is read by a device called a cryogenic magnometer. "This technique allows us to look far into the geologic past," Brown said. Some rocks are better recorders than others, according to Brown. The best samples are igneous, or volcanic rocks, which have strong magnetism. "You’ve got to make sure you understand the magnetic history of each sample," Brown noted.
Brown has been a member of the UMass faculty since 1974. She won an Outstanding Educator Award from the Association for Women Geoscientists in 1991.