Rock Pages

This 8-foot outcrop of folded limestone bumps up in a valley wetlands near the base of Mount Everett in southwestern Massachusetts. Hemlock, small pine, and various hardwoods subsist in the acidic, thin soil of decaying forest litter, their roots probing the cracked limestone beneath. If one imagines this nub without the trees and thin soil, one can see how the Wisconsin glacier ground the rock boundary into shape some 10,000 years ago.
Hundreds of millions of years before that, as shown by the thin layers at right, sea sediments alternated between relatively short periods of accumulating sea shells overlaid by coastal erosion. Moving up and left, the layers of calcium carbonate grow thicker as coastal sediments came less frequently or perhaps the coast moved further from this spot.
The layered sea floor was bent and folded in the slow collision of the North American Plate with the Eurasian/African plates in the making of the ancient supercontinent, Pangaea. At some point in that process, Mount Everett and other nearby high ground were pushed en masse over this limestone basement from perhaps 50 miles east of its present location. After several hundred million more years and the sundering of Pangaea by the growth of the Atlantic Ocean, at least three major glaciations scoured once-tall mountains and narrow valleys into today's Taconic and Berkshire Hills and broad valleys, underlaid by a deep bed of limestone, which in places offers its story on rock pages to those who take the time to read them.