Appalachian mountains the Appalachian mountains continental collision Appalachian Highlands continental collision http://geomaps.wr.usgs.gov/parks/province/appalach.html approximately 300 million years ago http://geomaps.wr.usgs.gov/parks/province/appalach.html оригіналу http://geomaps.wr.usgs.gov/parks/province/appalach.html http://geomaps.wr.usgs.gov/parks/province/appalach.html continental collision Appalachian highlands Appalachians оригіналу continental collision http://geomaps.wr.usgs.gov/parks/province/appalach.html Appalachian Highlands Province - USGS Geology in the Parks http://geomaps.wr.usgs.gov/parks/province/appalach.html http://geomaps.wr.usgs.gov/parks/province/appalach.html