At the beginning of the Paleozoic, the continents of Gondwana and Baltica are in the southern hemisphere and are separated by the Rheic Ocean.
The south-east of France is located on the northern margin of Gondwana under an epicontinental sea between the 30th and 60th degrees of southern latitude.
It is under this warm and dry tropical climate that marine sediments accumulate.
From 540 to 440 million years ago, the closure of the Rheic Ocean led to the formation of a new mountain range (New Caledonian orogeny) which transformed these sediments into metamorphic rocks, such as the phyllites of the peninsula. Giens, dated 440 million years ago.
