Urgonia

Urgon limestone above the Calanque de Sugiton (top left: the Grande Candelle , in the background the cliffs of Cassis )

Urgonian rocks of Grand Veymont and Mont Aiguille (from the south)

The urgonische Limestone is a limestone which abundant in the French Alps mountains ( Vercors , Chartreuse mountains and Bauges ) and in the southeast of France found. It is characterized by a very clear, frequent white color and its purity of calcium carbonate . It is very widely used as a building material because of its strength and white color.

Its name is derived from the municipality of Orgon ( Département Bouches-du-Rhône ), where the stone was mined or is still mined by the Omya company .

Origin and creation

The facies of the rock can be traced back to the way in which it was formed: it was formed by the deposition of barrier reef on the floor of a shallow sea and by a tropical climate. Dead animals ( rudists and orbitolines ) and algae were deposited in this ocean 115 million years ago and formed the “Uronic” limestone reef. As a result of the compression and uplift of the Pyrenees and Alps , the sea withdrew. After tectonic activities and the lowering of the sea level , this limestone was in the mountain massifs and was subsequently exposed by weathering.