How did those big crystals of blue quartz get locked into the pink granite of Mudd Hall? How come they’re blue? In Part 3 of the Columbia Geology Tour, David Walker of the Lamont-Doherty Earth Observatory explores the mysteries of granite formed deep in the earth more than 600 million years ago. Walker has for a decade or so led students and colleagues on a tour of the Columbia University campus, using building stones and features to illuminate the geological history of the planet.
Coming next week: At the Teachers College’s Russell Hall, evidence of the great oxygenation that transformed life on Earth. (You can watch all of the videos on YouTube here.)
