BOONE—A $43,495 grant from the National Science Foundation (NSF) will be used to purchase a cathodoluminescence (CL) microscopy system for Appalachian State University’s Department of Geology.

Dr. Sarah Carmichael, an assistant professor in the department, said the microscope will enable faculty and students to identify features that otherwise remain invisible through traditional light microscopy or scanning electron microscopy.

This image of a common mineral called anhydrite was taken with a cathodoluminescence (CL) microscopy system. Appalachian State University has received a $43,495 National Science Foundation award to purchase a CL microscope for the Department of Geology. The zones and colors seen in the photo are not visible under any other kind of microscope or imaging system.
Currently, researchers must travel four hours from campus to use such equipment. The new microscope should be in use by spring semester 2010. (Photo by Dr. Sarah Carmichael, Department of Geology)

“When a polished rock or forensic evidence sample is bombarded with electrons from a cathode ray, certain minerals or man-made materials will emit visible light,” she explained. “This light is emitted at specific wavelengths, which allows geologists to see fine differences in material composition as well as any structural defects. This makes the CL microscope an invaluable tool for mapping microstructures, trace element variability and growth zones in a variety of minerals, and also for identification of a variety of materials in forensic science applications.

Carmichael co-wrote the grant with Dr. Cynthia Liutkus, also an assistant professor in the Department of Geology. Carmichael will use the microscope to map manganese mobility in cave deposits and carbonate rocks in the southern Appalachians and to obtain images of fluid-rock interactions in altered basalts and hydrothermal vent chimneys at the 9°50′N East Pacific Rise Integrated Study Site, a hydrothermal vent field approximately 500 miles south of Manzanillo, Mexico, in the Pacific Ocean where the Pacific Plate and the Cocos Plate are separating and a new ocean crust is being formed.

Liutkus will use the microscope to investigate mineral precipitation around plants in both modern and ancient lake and wetland environments, and to determine whether or not groundwater has interacted with sediment samples prior to chemical analysis.

The new equipment should be in operation by spring semester 2010. It will be housed in the Department of Geology’s Optical Petrography Lab and will be used primarily by faculty and students from the departments of geology and chemistry. It will also be available to researchers from other academic institutions in western North Carolina, East Tennessee, and southwest Virginia.  Until now, there was no CL system available within a four-hour radius of the university.

Because the CL requires minimal sample preparation, is easy to use, and has a colorful visual output, it will be used as a teaching tool in a variety of undergraduate classes in the geology and chemistry departments.

Undergraduates conducting independent research in mineralogy, petrology, sedimentology, paleontology, structural geology and forensic science will also use this microscope.  Other professors who will use the new microscope include Libby Puckett, an assistant professor in the Department of Chemistry; Professor Richard Abbott, Associate Professor Steve Hageman, Instructor Crystal Wilson and Technician Anthony Love from the Department of Geology; and Assistant Professors Yongli Gao and Arpita Nandi in the Department of Geosciences at East Tennessee State University.

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