Belvedere to the north

To the north, below, we can find hills of gray clays. Insignificantly, these clays and the fossils they contain allowed the creation, in 1840, of one of the stages of the international stratigraphic scale which breakdown the history of the Earth, in eras, period, stages .. . Since its formation more than 4 billion years ago. This floor is the Aptian, which takes its name from Apt, of course, between -125 and -113 million years ago.