The Cap Ferret is the small end of the peninsula of Lège-Cap-Ferret. The seaside resort was constructed by the accumulation of a stretch of sand which was greatly extended by the intermediary of the coastal currents which were derived from the north-south coast. This situation has happened 2,000 years ago, but actually this is what made of Cap Ferret what it is at the present time.
Wind and marine erosion has particularly shaped the Pointe du Cap Ferret through cyclical phenomena during the opening of the Bassin d'Arcachon passes during low tides. Experts have conducted some observations of the "sandy arrow" for 250 years and studies have shown a strong increase in 60 years: the sandy surface has a surplus of areas of 70 m while the internal shore has degraded.
The Cap Ferret is known for its shape of cord located to the littoral of the extreme south of the peninsula of Lège-Cap-Ferret in Gironde. It is used for a separation between the Atlantic Ocean and the Bassin d'Arcachon. Its floor is made of layer of sandstone coming from the cementation of the grains of quartz, it is what is also called "the layer of Alios". Its water flows in the sheet, this is what causes the presence loaded with iron in its consistency. When rivers throw themselves on the beach, the latter produce oxidized traces taking colors of rust.
Among other things, Cap Ferret is chock - full of drilling riches invading an oil slick located at a depth of 3,200 meters. These resources belong particularly to the Aquitaine basin. The peninsula inaugurated its first well in 1962, exploiting a deviated drill hole called "Lavergne". This one is found under the sea between the Point and the Bank of Arguins, but was then moved to the north because of the strong erosions.