Triassic Triassic The Triassic () is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.9 million years ago (Mya), to the beginning of the Jurassic Period Mya. The Triassic is the first period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it would take well into the middle of this period for life to recover its former diversity. Therapsids and archosaurs were the chief terrestrial
Verdon Gorge the Triassic period, the French region of Provence subsided and was covered by the sea, leaving thick layers of various limestone deposits. Several million years later, with the arrival of the Jurassic period, the area was covered by a warm shallow sea, which allowed the growth of various Corals. The Cretaceous period saw what is now Basse Provence being raised and the sea reaching the current location of the Alps, which were themselves erected during the tertiary era. As a result of the large-scale geological activity, many of the Jurassic limestone deposits fractured, forming relief with valleys and other such