The U.S. Department of Energy (DOE) will give $4.8 million to 21 U.S. universities for new instruments for energy-related research, it was announced last week. The 24 successful proposals were selected from 188 applications. Four of the University Research Instrumentation Awards are designated for geoscience research.
The minute sources of remanent magnetization in rocks will be investigated by John Geissman of the Univeristy of New Mexico in Albuquerque (UNM) with a magnetometer of special design, funded by a DOE grant of $115,000. Paleomagnetic measurements are generally based on a bulk determination of magnetization of 11 cm3 or so of rock. “But the size of particles that are the source of geologically stable remanent magnetism is very small,” says Geissman. His magnetometer is designed to analyze particles as small as a micron. It will be used with a scanning/transmission electron microscope (STEM) at UNM to explore where the small grains reside in rocks and to gain a fuller understanding of the paleomagnetism measured by conventional means. Future work may also involve using a laser to destroy selected magnetic phases and minimize the effects of parts of the magnetic mineralogy, permitting examination of any magnetic material that remains.