Geology of the Appalachians craton. The collisional belt spread into the Ozark-Ouachita region and through the Marathon Mountains area of Texas. Continent vs. continent collision raised the Appalachian-Ouachita chain to a lofty mountain range on the scale of the present-day Himalaya. The massive bulk of Pangea was completed near the end of the Paleozoic Era (Permian Period) when Africa (Gondwana) plowed into the continental agglomeration, with the Appalachian-Ouachita mountains near the core. Pangea began to break up about 220 million years ago, in the Early Mesozoic Era (Late Triassic Period). As Pangea rifted apart a new passive tectonic margin was born and the forces
Robert Frost Trail (Massachusetts) Hadley, South Hadley, Amherst, Granby, Belchertown, Pelham, Shutesbury, Leverett, Sunderland, Wendell and Montague. The Robert Frost Trail might be divided into three general geo-ecological landscapes. Both the Holyoke Range and Mount Toby were formed 200 million years ago between the end of the Triassic period and the beginning of the Jurassic. The Holyoke Range, part of the Metacomet Ridge that extends south to Long Island Sound, are composed of basalt, an extrusive volcanic rock. This basalt ridge is the product of several massive lava flows hundreds of feet deep that welled up in faults created by the rifting apart of