Recently, many members of the Geosciences Faculty took a field trip to the Stetson-Sawyer construction site to do what they love – examine rocks. In particular, they were interested in the ledge that has been the subject of great attention and the source of a tremendous amount of noise both on campus and throughout town. Here is what the faculty had to say about the ledge:
“The rock ledge that lies beneath the Stetson-Sawyer building site is mostly quartzite. There are interlayers of micaceous rock (phyllite or schist) that mark old fault zones. The rocks are close to half a billion years old, and record the presence of a shallow, probably warm, ocean in this area. The quartzite is extremely hard. It consists of quartz sand grains (with some carbonate material) that are completely cemented together with silica, and there are almost no joints or fractures in the rock—which explains why it’s such a difficult (and noisy) job to hammer out the building site.”
BBL/Skanska engineer Peter Usher led the tour and took all but the first photo.