Did you know that there are caves in the hills around Bennington?
Tim Schroeder‘s The Geology of the Bennington Region class explored one such cave on the north side of Mount Anthony on a recent class field trip. The caves are present in the Ordovician marble deposits that have been quarried in this region for centuries. The rocks were originally deposited as limestone in a reef-like setting when Bennington was on the margin of North America 500 million years ago. The rocks were metamorphosed to become marble during the tectonic events that built the Appalachian Mountains. The caves form now because the mineral calcite, which composes the marble, is slightly soluble in acidic rain water, and it slowly dissolves openings as the rainwater infiltrates into fractures in the marble. This particular cave is located very near one of the major faults that formed the Taconic range, which we also mapped on this field trip.