Philipp Brandl (Igneous Petrologist, University of Erlangen-Nürnberg, Germany) examines thin section samples. Thin sections are samples of stone or sand-like material which are bonded to a glass microscope slide. In the Thin Section Laboratory aboard the ship, the samples are cut and finally polished to a thickness of 30 µm or less. This is approximately the thickness of a human hair. When the sample is this thin, visible light will pass through it. A special microscope contrasting method called cross polarization reveals unique colors and densities which to a petrologist can indicate the type of mineral being viewed. “We have been pleasantly surprised by such ‘fresh’ crystals.” said Brandl. “These crystals have not been subjected to corrosive influences of fluids, heat, and mechanical factors which can degrade the specimen. Fresh crystals allow us to get much more accurate data. Such a find has been exciting to see.” Philipp is currently working with Richard Arculus in Australia. (Credit: Bill Crawford, IODP/TAMU) [Photo ID: exp351_039] Back to expedition photos. |