Jurassic Jurassic The Jurassic (; from Jura Mountains) was a geologic period and system that spanned 56 million years from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period Mya. The Jurassic constitutes the middle period of the Mesozoic Era, also known as the Age of Reptiles. The start of the period was marked by the major Triassic–Jurassic extinction event. Two other extinction events occurred during the period: the Pliensbachian-Toarcian extinction in the Early Jurassic, and the Tithonian event at the end; however, neither event ranks among the "Big Five" mass extinctions. The
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