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
St Brides Major (community) St Brides Major, the Dunraven estate and Clemenstone Meadow SSSI. Much of the coastline of the community is designated as the Southerndown Coast SSSI, both for its geology and botanic value. The stretch of shore, cliff, cliff-top, and several short, steep valleys, reveal the local geological strata. Carboniferous Limestone from upwards of 300 million years ago lies at the present sea level. By the Triassic period, 200 million years ago, these rocks were already tilted and eroded. A new deposition phase created more sedimentary rocks, including a red Triassic conglomerate, and a creamy white Jurassic limestone known as Sutton Stone,