Paleontology and geologyAlmost as soon as Pangea formed, it began to break apart. As the continents separated, part of Gondwana and its accumulated continental and marine deposits were left behind, and these rocks became part of the Northeastern Region of Mexico. This rifting formed large basins, pushed other areas up, and thinned the crust, allowing magma to approach the surface. Blocks of granite formed below older rocks and volcanoes poured lava and ash over the land. Rivers carried eroded sediments to seas in the east and west. Many different plants covered the land, as evidenced by fossil pollen, spores, and wood found in continental sandstones and mudstones. By the end of the period, subduction along the western edge of the continent pushed oceanic deposits up against the continent. Many of these rocks have been altered, folded, and faulted, and only poorly preserved coral fossils have been recovered from them. Exposures of Triassic rocks can be found in a few small areas in the south. |