Long Durational Natural Phenomenon

Existence of Verdon Gorge 

Duration: 199.6 Million Years

Text via Wikipedia
Cover photograph CC BY-SA 3.0 Benh Lieu Song

The Verdon Gorge, in south-eastern France, is a river canyon that is often considered to be one of Europe's most beautiful. It is about 25 kilometers long and up to 700 meters deep. It was formed by the Verdon River, which is named for its startling turquoise-green color and is one of the location's distinguishing characteristics. The most impressive section lies between the towns of Castellane and Moustiers-Sainte-Marie, where the river has cut a 700-meter deep ravine through the limestone mass. At the end of the canyon, the Verdon River flows into the artificial lake of Sainte-Croix-du-Verdon. 

Photograph CC BY-SA 3.0 Joseph Plotz

During 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 for the growth of coral. During the Cretaceous period, Basse Provence was raised and the sea reached 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 features. The origins of the Verdon Gorge can be traced to this era. The dawn of the Quaternary period had large-scale glaciation, transforming water pockets and lakes into unstoppable rivers of ice, which remodeled the topography, scouring and striating the landscape. At the end of this activity, erosion by rivers continued, forming the Gorge as it is today. 

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